Showing papers in "Endocrinology in 1962"
TL;DR: It is found that this explanation is too simple and that there are, in fact, 2 hormones from the parathyroid involved—parathormone, released by hypocalcemia, and a hypocalcemic factor, calcitonin, which is released by hypercalcemia.
Abstract: It has been assumed that the parathyroids control the level of blood calcium by a feedback mechanism whereby hypocalcemia stimulates parathormone production while hypercalcemia inhibits it. In the following experiments we have found that this explanation is too simple and that there are, in fact, 2 hormones from the parathyroid involved—parathormone, released by hypocalcemia, and a hypocalcemic factor, calcitonin, which is released by hypercalcemia. In studies on fasted anesthetized dogs, perfusion of the isolated thyroid-parathyroid glands with high calcium blood (12 mg per 100 ml) caused an immediate fall in systemic blood calcium, even in the presence of intact thyroid and parathyroid glands on the opposite side. Hypercalcemic perfusion of the thyroid gland alone was without effect. The fall in plasma calcium resulting from parathyroid hypercalcemia was significantly sooner and greater than that following total surgical thyroparathyroidectomy. This difference in response was even more striking after a ...
622 citations
TL;DR: The findings encountered give further support to the theory that a small portion of a protein hormone molecule may determine major differences in its physiologic function.
Abstract: A previously undescribed substance has been discovered in the peripheral and retroplacental sera of human pregnancy at term. This substance is immunochemically closely related to human pituitary growth hormone (HGH) and has been isolated in relatively large amounts and purified form from term human placentas. It is highly lactogenic both in pigeon crop sac assays (local intradermal injections) and in milk-promoting activity in the pseudopregnant rabbit, but is devoid of growth-promoting activity in the hypophysectomized rat tibial plate growth assay at the dose levels tested. The possible biologic role of this lactogenic material in pregnant primates is discussed. The findings encountered give further support to the theory that a small portion of a protein hormone molecule may determine major differences in its physiologic function.
324 citations
TL;DR: The effects of ovariectomy and ovarian hormones on brain excitability were investigated in rats by measuring: (a) minimal electroshock seizure threshold, and (b) maximal electro shock seizure pattern.
Abstract: The effects of ovariectomy and ovarian hormones on brain excitability were investigated in rats by measuring: (a) minimal electroshock seizure threshold, and (b) maximal electroshock seizure pattern. Increased excitability or greater convulsive reactivity is indicated by a decreased threshold and by alterations in the duration of the tonic and clonic components of a maximal seizure, i.e., shortening of tonic flexion and/or lengthening of tonic extension. These procedures and treatments were studied: (a) ovariectomy, before and after puberty, with or without hormonal replacement therapy; (b) administration of estradiol and progesterone, alone or in combination, in intact, castrated or hypophysectomized male or female rats; and (c) administration of testosterone and methylandrostenediol to compare the central nervous effects of male and female sex steroids. Body and organ weights were measured and compared with the changes in convulsability. The main results were: (a) Ovariectomy. After sexual maturation in...
226 citations
TL;DR: Various levels of dosage of prolactin and/or growth hormone, alone and in combination with thyroxine and prednisone, were injected daily for 10 days into hypophysectomized pigeons, finding greater increases in the weight of body and of organs when the auxiliary solution was found.
Abstract: Various levels of dosage of prolactin and/or growth hormone, alone and in combination with thyroxine and prednisone, were injected daily for 10 days into hypophysectomized pigeons. Adequate doses of prolactin or of growth hormone alone or together increased the weight of the body, liver, pancreas, intestines and kidney. There was no apparent synergism. Greater increases in the weight of these structures were found when the auxiliary solution of thyroxine (10 μg) and prednisone (1 mg) was injected simultaneously. Thyroxine and prednisone together did not increase organ weights but acted as permissive agents when combined with growth hormone and/or prolactin. Synergisms of the order of 50-fold were obtained when all 4 hormones were injected. Twenty μg of prolactin plus 20 μg of growth hormone with the auxiliary solution produced a greater increase in weight of body and of organs than was obtained with 2 mg of growth hormone and prolactin without the auxiliary solution. Prednisone appeared to conserve body f...
155 citations
TL;DR: It may be concluded that autologous parathyroid hormone in amounts secreted by the glands can act as a calciphylactic sensitizer.
Abstract: Earlier work has shown that pretreatment with parathyroid extract sensitizes the rat to the production of a calciphylactic syndrome characterized by selective calcinosis in the left auricular appendage and the extrahepatic bile-duct system. The present experiments indicate that similar sensitization can be achieved by bilateral nephrectomy, but only in the presence of the parathyroids. Hence, it may be concluded that autologous parathyroid hormone in amounts secreted by the glands can act as a calciphylactic sensitizer.
134 citations
TL;DR: The effects of hypophysectomy and of restitutional therapy with ACTH on the fine structure of the rat adrenal cortex were studied with the electron microscope and the predominant changes consist in degeneration and atrophy.
Abstract: The effects of hypophysectomy and of restitutional therapy with ACTH on the fine structure of the rat adrenal cortex were studied with the electron microscope. During the first week after hypophysectomy the only change was the lack of protruding mitochondrial vesicles frequently observed in the normal fasciculata and reticularis. After two weeks there are marked changes in the mitochondria of the outer fasciculata consisting in the modification of the normal vesicular pattern that leads to the appearance of tubulovesicular elements and convoluted tubules. At the same time the relative proportion of mitochondrial matrix increases. In more advanced stages mitochondria contain a few straight tubuli and assume a pattern similar to that found in the normal glomerulosa. In the inner zones the predominant changes consist in degeneration and atrophy. With time the lipid droplets of the entire gland become dissolved during the preparation of the material. The glomerular cells show no marked changes with hypophysec...
122 citations
TL;DR: The endocrine-morphologic relationship between the pancreatic islet cells of the fowl was investigated by morphologic observation of the architecture and distribution of the islets and physiologic examination of fowls deprived of the alpha-islet-containing portion of the pancreas.
Abstract: The endocrine-morphologic relationship between the pancreatic islet cells of the fowl was investigated by morphologic observation of the architecture and distribution of the islets and physiologic examination of fowls deprived of the alpha-islet-containing portion of the pancreas. There were 2 types of islets in the fowl pancreas: one was an “alpha” islet composed of alpha and delta cells and the other -was a “beta” islet made of beta and delta cells. Beta islets were scattered throughout the gland, while alpha islets were confined to the 3rd and splenic lobes. It was suggested that carbohydrate metabolism was essentially the same in the fowl as in the mammal, because they exhibited the same sensitive hyperglycemic response to glucagon and hypoglycemic response to insulin. A physiologic investigation of changes in fowls deprived of alpha islets was accomplished by means of selective removal of the alpha-islet-containing portion, or the 3rd and splenic lobes, from the pancreas. The birds having received su...
121 citations
TL;DR: It was demonstrated that the pituitary explants were capable of synthesizing and releasing almost as much prolactin each day as they contained at the beginning of culture.
Abstract: Explants from anterior pituitaries of mature female rats were cultured by a watch glass technique for 6 or 7 days in synthetic medium “199.” The medium was assayed for prolactin activity by the sensitive intradermal pigeon crop method. It was demonstrated that the pituitary explants were capable of synthesizing and releasing almost as much prolactin each day as they contained at the beginning of culture. An average of 0.8 Reece-Turner prolactin units (approximately 0.1 iu) was produced per pituitary each day in cultures maintained in 95% O2-5% CO2 atmosphere. Medium incubated without any tissue had no prolactin activity. Considerable prolactin activity was still detected in the medium at the end of a 3-week culture, showing that the explants continued to produce prolactin for the entire period. Histological examination of the pituitary explants at the end of the culture period revealed that the cells were in a viable state. In 10 trials, addition of 0.5 μg estradiol per cc of medium significantly increase...
118 citations
TL;DR: The retrograde technique, while less precise, provides greater adrenal sensitivity to minute doses of ACTH than heretofore described, and is adaptable to the measurement ofACTH in biologic fluids.
Abstract: Fluorometric determination of corticosteroids in adrenal venous plasma of the acutely hypophysectomized rat has led to the development of 2 new techniques for the measurement of ACTH. The first, consisting of jugular injection of test material, with adrenal venous bleeding 5 minutes later, gives linearity of response to log doses of ACTH ranging from 0.05 to 1.0 milliunits (mU). The second method, consisting of retrograde injection of ACTH up the adrenal vein, with adrenal venous bleeding 90 seconds later, gives linearity of response over a range from 0.005 to 0.5 mU ACTH. The retrograde technique, while less precise, provides greater adrenal sensitivity to minute doses of ACTH than heretofore described. These methods are adaptable to the measurement of ACTH in biologic fluids.
117 citations
TL;DR: Parametrial adipose- tissue taken from rats adrenalectomized 8 hours utilized more glucose and released less fatty acid than did tissue from normals; treatment with dexamethasone restored these values to normal.
Abstract: Parametrial adipose- tissue taken from rats adrenalectomized 8 hours utilized more glucose and released less fatty acid than did tissue from normals; treatment with dexamethasone restored these values to normal. Although the fatty acid release in vitro was 10-fold greater in rats given growth hormone and glucocorticoid, plasma free fatty acids and ketone bodies were the same as those in rats given either hormone alone.
116 citations
TL;DR: Other features of the giant cells indicating their function in the production of steroid hormones are a conspicuous amount of cytoplasmic lipid and a high capacity for making reduced triphosphopyridine nucleotide (TPNH) as a result of oxidation of glucose-6-phosphate.
Abstract: Implantation sites of rats (pregnant 10 to 21 days) and of mice have been assayed for Δ5-3β-hydroxysteroid dehydrogenase activity by histochemical and biochemical methods. Histochemically, activity was limited to the peripheral giant trophoblasts of the fetal placenta. In rats, enzymic activity was found by both methods to rise to a peak at about 13 to 15 days of gestation and thereafter to decline. This enzyme is required for oxidation of C19 and C21 Δ5-3β-hydroxysteroids to Δ4-3-ketosteroids and thus plays a key role in the biosynthesis of the active steroid hormones. Other features of the giant cells indicating their function in the production of steroid hormones are a conspicuous amount of cytoplasmic lipid and a high capacity for making reduced triphosphopyridine nucleotide (TPNH) as a result of oxidation of glucose-6-phosphate. Some confirmatory evidence has also been presented for local erosive activity and trophic-hormone production by the giant cells. The attributes of the giant cells in rat and ...
TL;DR: It is suggested that 5 of the 6 known anterior pituitary hormones (GH, LTH, TSH, LH and FSH) are produced by these 5 classes of cells.
Abstract: The secretory cytology of mouse anterior pituitary has been investigated by means of electron microscopy, controlled by light microscope procedures. The material examined included: tissue from animals in various normal functional states, and from animals which had been castrated. Five morphologically distinct and easily recognized varieties of secretory cells are present in mouse pituitary tissue. The fine structure of each variety is described and illustrated. Provisional functional identities have been assigned to these 5 cellular classes by studying their respective reactions to functional change. It is suggested that 5 of the 6 known anterior pituitary hormones (GH, LTH, TSH, LH and FSH) are produced by these 5 classes of cells. In light microscope studies, a group of cells homogeneous with respect to a particular staining affinity may well not be homogeneous with respect to function. The results of the present study suggest that each of the 5 groups of cells, identified in the electron microscope on ...
TL;DR: Synthetic Oxytocin and analogues of oxytocin exert an insulinlike action on the utilization of glucose by rat epididymal adipose tissue and appears to be dependent upon the factors that determine the oxytocic properties of the peptides.
Abstract: Synthetic oxytocin and analogues of oxytocin exert an insulinlike action on the utilization of glucose by rat epididymal adipose tissue. The insulinlike action appears to be dependent upon the factors that determine the oxytocic properties of the peptides.
TL;DR: The observation that insulin in its complex form is devoid of insulin activity, when assayed in vitro under specified conditions, resulted in the finding that factors present in adipose tissue extracts could dissociate the blood insulin complex (es).
Abstract: New techniques have been introduced by the authors and collaborators in the course of their studies on the state, transport and regulation of insulin in man. The discovery that a portion of insulin in blood circulates in a complex form extractable by cationic exchange resins (Nacycle) led to the development of a simple technique for the separation of this portion of insulin from whole serum. The observation that insulin in its complex form is devoid of insulin activity, when assayed in vitro under specified conditions, resulted in the finding that factors present in adipose tissue extracts could dissociate the blood insulin complex (es). Methods have been developed therefore for the extraction, storage, preservation and “standardization” of these factors from adipose tissue. Studies on the ratio of “free” and “bound” insulin-like activity in serum suggest that this ratio does not represent a purely physicochemical equilibrium between “bound” and “free” insulin. This ratio depends upon the metabolic state ...
TL;DR: The formation of estrogens and phenolic material from a large number of do Cis, C19 and C2i steroids and related structures has been investigated, employing a human placental microsomal preparation supplemented with TPNH and oxygen.
Abstract: The formation of estrogens and phenolic material from a large number of do Cis, C19 and C2i steroids and related structures has been investigated, employing a human placental microsomal preparation supplemented with TPNH and oxygen. The data from the incubation of 2 C 14-labeled androgens are included. There is a discussion of possible biosynthetic pathways for the estrogens.
TL;DR: After a single injection of thyroid- stimulating hormone (TSH) to rats, discrete droplets were located in one or more of 3 sites: within streamers of cytoplasm extending into the lumen from the apex of the follicular cells, within the body of the cells either toward the apex or toward the base.
Abstract: After a single injection of thyroid- stimulating hormone (TSH) to rats, discrete droplets, which stain like the colloid in the lumen, were located in one or more of 3 sites: 1) within streamers of cytoplasm extending into the lumen from the apex of the follicular cells, 2) within the body of the cells either toward the apex or 3) toward the base. In a first experiment, counts of colloid droplets in these 3 locations after TSH injection indicated that they appear first in the cell streamers, later in the apex, and finally in the base of the cells. In a second experiment, colloid droplets were produced again by TSH, but in animals given leucine-H3 either ½ hour before sacrifice (when radioautography showed labeling solely of follicular cells) or 5 ½ hours before sacrifice (when labeling predominated in the luminal colloid). Only in the latter case was there any significant labeling of the colloid droplets. The interpretation was that the droplets originate from the luminal colloid—a conclusion in keeping wi...
TL;DR: Two substances, peptides I and II, isolated from a crude extract obtained from the anterior pituitary glands of hogs, had a potent effect on lipid metabolism in rabbits; as little as .02 μg added to leporine adipose tissue in vitro stimulated the release of free fatty acids.
Abstract: Two substances, peptides I and II, isolated from a crude extract obtained from the anterior pituitary glands of hogs, had a potent effect on lipid metabolism in rabbits; as little as .02 μg added to leporine adipose tissue in vitro stimulated the release of free fatty acids. Following the injection of 10 μg intravenously, the concentration of free fatty acids in plasma increased threefold within 5 minutes, while 2.5 mg subcutaneously resulted in gross lipemia from 12 to 16 hours later. Their effect in man was slight; from 5 to 25 mg produced only a small increase in free fatty acids in one hour. Similarly, an impure preparation of peptides I and II from human pituitaries failed to produce a clear change in free fatty acids in man. Starch gel electrophoresis of the crude pituitary extract as well as of peptides I and II was performed, and by this method the major component of “Fraction H” prepared by Rudman was identical with peptide II.
TL;DR: Fatty acid synthesis in the carcass, liver and adipose tissues of rats was examined in vivo by measuring the amount of tritium recovered in fatty acid and Adrenalectomy did not result in any marked alteration of fatty acid synthesis.
Abstract: Fatty acid synthesis in the carcass, liver and adipose tissues of rats was examined in vivo by measuring the amount of tritium recovered in fatty acid. Fatty acid synthesis was accelerated in adult female rats fed a low fat diet as compared with animals fed laboratory chow. Adrenalectomy did not result in any marked alteration of fatty acid synthesis. In hypophysectomized rats, fatty acid synthesis was consistently depressed and was restored to normal by thyroxine treatment. Continued treatment with growth hormone had no effect on fatty acid synthesis in either normal or hypophysectomized female rats fed laboratory chow. In normal, but not adrenalectomized, rats on the low fat diet, continued growth hormone treatment depressed carcass fatty acid synthesis. A single dose of growth hormone depressed fatty acid synthesis by one half in fed female rats on laboratory chow, in which fatty acid synthesis was measured between the 6th and 14th hours after the administration of growth hormone.
TL;DR: The sexual dimorphism of the mouse submaxillary salivary gland was investigated with regard to the NGF content, and injections of testosterone in female mice called forth a marked increase of this factor and castration of adult male mice resulted in a sharp decrease of thisfactor.
Abstract: It has been reported in previous work that the mouse submaxillary salivary glands contain a potent nerve-growth factor (NGF) that promotes the differentiation and growth of the sympathetic ganglia. It also has been reported that this factor is a protein that is present in higher concentration in the adult male than in the adult female gland. In the present paper the sexual dimorphism of the mouse submaxillary salivary gland was investigated with regard to the NGF content. Injections of testosterone in female mice called forth a marked increase of this factor. Conversely, castration of adult male mice resulted in a sharp decrease of the NGF. The relationship of the salivary protease to the NGF, both located in the tubular components of the gland, was investigated after ligature of the excretory duct of the gland. The possible role of the submaxillary salivary gland in the production of the NGF is discussed in the light of the present findings.
TL;DR: Extracts of hog hypothalamus were chromatographed on carboxymethylcellulose and the following substances were tentatively identified in the effluents based on elution volumes and biological activities: oxytocin, β-MSH, α MSH, lysine vasopressin,β-CRF, an αMSH- like or ACTH-like peptide and ACTH.
Abstract: Extracts of hog hypothalamus were chromatographed on carboxymethylcellulose. The following substances were tentatively identified in the effluents based on elution volumes and biological activities: oxytocin, β-MSH, αMSH, lysine vasopressin, β-CRF, an αMSH-like or ACTH-like peptide and ACTH.
TL;DR: It was concluded that progesterone alone was incapable of reproducing the weight and water content of the deciduomata of intact pseudopregnant rats, and that combinations of estrogen and progester one that were effective were similar to those reported for the optimal maintenance of gestation.
Abstract: Massive deciduomata weighing 2,000 mg per uterine horn were induced mechanically in intact pseudopregnant rats. Castration and treatment with progesterone evoked maximal responses of only 1,000 mg. The concomitant administration of estradiol or estrone with progesterone reproduced the decidual weight observed in intact rats, but estriol in combination with progesterone was only slightly effective. The decidual cell response was found to be sensitive to alteration in steroid ratio as well as in absolute dose levels. The water content of deciduomata in intact rats was 84.3%. Only those combinations of hormones that produced maximal weights could reproduce the water content observed in the intact pseudopregnant rat. It was concluded that progesterone alone was incapable of reproducing the weight and water content of the deciduomata of intact pseudopregnant rats, and that combinations of estrogen and progesterone that were effective were similar to those reported for the optimal maintenance of gestation.
TL;DR: The thymus increased in weight after castration and decreased on androgen administration with concomitant changes in both DNA and RNA and the total RNA was increased during the period of rapid growth of the tissues to values above normal and then decreased to normal levels as the rate of growth ofThe tissues decreased.
Abstract: Castration of adult male mice produced a progressive decrease in the weight of the kidney to a plateau at about 65% of normal within 14 days accompanied by a proportionate decrease in s-RNA. The total DNA also decreased but to a smaller degree while the total RNA decreased to a greater degree than the weight. Similar but greater decreases were observed in the prostate and seminal vesicles. The administration of testosterone propionate, testosterone, 17-methyltestosterone or androstan-17β-ol, 3-one gradually reversed the effects of castration. In addition the total RNA was increased during the period of rapid growth of the tissues to values above normal and then decreased to normal levels as the rate of growth of the tissues decreased. The thymus increased in weight after castration and decreased on androgen administration with concomitant changes in both DNA and RNA. The liver weight decreased slightly with proportionate decreases in s-RNA and RNA but not in DNA. Androgen administration reversed these cha...
TL;DR: A soluble enzyme functioning as an iodide-peroxidase and tyrosine-iodinase complex has been prepared from sheep thyroid tissue and Methimazole behaves in the enzyme assay system as a strict competitive inhibitor of iodide.
Abstract: A soluble enzyme functioning as an iodide-peroxidase and tyrosine-iodinase complex has been prepared from sheep thyroid tissue. The enzyme is detached from cell particles by chymotrypsin digestion in the presence of deoxycholate, followed by a butanol and acetone extraction procedure. It can be purified by diethyl-amino-ethyl cellulose column chromatography. During preparation specific activity of the enzyme is enhanced fiftyfold. The enzyme appears to be a basic protein which does not contain a porphyrin group. It has no cytochrome oxidase activity. Iodinase activity is thermolabile, and dependent on an H2O2 source. Under suitable conditions the enzyme forms both diiodotyrosine and monoiodotyrosine from soluble tyrosines, and iodinates proteins. Tyrosine and monoiodotyrosine are its only well-defined amino acid substrates. Methimazole behaves in the enzyme assay system as a strict competitive inhibitor of iodide.
TL;DR: The adipose tissue of the rabbit treated with Fraction H exhibited hyperemia and contained an 11-fold greater average concentration of FFA than that of the normal rabbit, and lowering of serum CO2 content occurred during the mobilization of F FA.
Abstract: Previous reports described the preparation from hog pituitary glands of a fraction (labeled “Fraction H”) which is highly active in mobilizing free fatty acids (FFA) into the serum of the rabbit. In this report, certain metabolic changes produced in the rabbit by porcine Fraction H are examined in more detail. The adipokinetic activity of porcine Fraction H in the rabbit, guinea pig, rat and mouse are compared. The injection of 3 mg of porcine Fraction H in the rabbit caused a 10-fold increase in serum FFA within 2 hours, which persisted for more than 8 hours. The adipose tissue of the rabbit treated with Fraction H exhibited hyperemia and contained an 11-fold greater average concentration of FFA than that of the normal rabbit. Lowering of serum CO2 content occurred during the mobilization of FFA. A slight reduction in R.Q. was found but there was no change in blood sugar concentration. Acetonemia did not appear. Four hours after the injection, there were 5- to 8-fold increases in the concentrations of li...
TL;DR: Thyroxine-protein interactions in a variety of vertebrate species of the Classes Mammalia, Aves, Reptilia, Amphibia and Pisces have been studied by electrophoresis in filter paper and starch gel and it has been found that a specific thyroxin-binding alphaglobulin occurs only in mammals.
Abstract: Thyroxine-protein interactions in a variety of vertebrate species of the Classes Mammalia, Aves, Reptilia, Amphibia and Pisces have been studied by electrophoresis in filter paper and starch gel. It has been found that a specific thyroxine-binding alphaglobulin occurs only in mammals. All other vertebrates probably have proteins capable of binding thyroxine less strongly. Intraspecies genetic variability in thyroxine-binding patterns may occur. Each animal should be investigated thoroughly by a variety of methods in order to comprehend fully the thyroxinebinding capabilities of its serum proteins.
TL;DR: The amount of TSH reported to be present in the growth hormone preparations is sufficient to account for the effect of these preparations on the oxygen uptake of adipose tissue.
Abstract: An attempt has been made to define the principle (s) present in growth hormone preparations responsible for their effect in vitro on the oxygen uptake of rat epididymal adipose tissue. An examination of whole pituitary powder and 8 fractions derived therefrom revealed that the active principle was present in the largest amounts in those fractions richest in TSH, while the fractions richest in growth hormone possessed a relatively low activity. Purified samples of TSH were found to be very active in increasing the oxygen uptake, and this stimulatory activity was proportional to the TSH content of the preparations. The oxygen uptake of adipose tissue was increased by the addition of as little as a few tenths of a milliunit per ml of TSH. The amount of TSH reported to be present in the growth hormone preparations is sufficient to account for the effect of these preparations on the oxygen uptake of adipose tissue. It is suggested that certain previously described actions of growth hormone preparations on adip...
TL;DR: Evidence is presented to support the hypothesis that while some increase in intracellular concealing activity in rats incubated in vitro in a Krebs-Ringer bicarbonate medium, the unnatural L(+) isomers of adrenaline and noradrenaline are less active than the natural D(−) isomers.
Abstract: The uptake of glucose by rat epididymal adipose tissue incubated in vitro in a Krebs-Ringer bicarbonate medium is influenced by the presence or absence of bovine serum albumin in the medium. Without albumin glucose uptake is significantly higher than when albumin is present at concentration of 2–4%. Adrenaline, noradrenaline and ACTH, all of which stimulate lipolysis in adipose tissue in vitro, inhibit glucose uptake when there is no albumin in the medium and stimulate it when albumin is present. Insulin promotes glucose uptake irrespective of the presence of albumin, but this response to insulin is inhibited by the lipolytic hormones when there is no albumin in the medium. Both the inhibitory and stimulatory actions of ACTH in the different media are abolished by chemical inactivation of ACTH. Furthermore, the unnatural L(+) isomers of adrenaline and noradrenaline are less active than the natural D(−) isomers. Evidence is presented to support the hypothesis that while some increase in intracellular conce...
TL;DR: Injection of partially purified renin to animals pretreated with aldosterone plus salt caused a syndrome similar to the DCArenin disease which is characterized by occlusive glomerular lesions, renal failure, water retention, hemorrhages and acute vascular lesions.
Abstract: Daily doses of 0.2 mg of Daldosterone-21-acetate in sesame oil caused a mild type of hypertension without vascular disease in uninephrectomized rats given tap water or 1 % saline to drink. Renal secretion of pressor substances ceased and renal content decreased following aldosterone plus salt or water. Injection of partially purified renin to animals pretreated with aldosterone plus salt caused a syndrome similar to the DCArenin disease which is characterized by occlusive glomerular lesions, renal failure, water retention, hemorrhages and acute vascular lesions. The similarity of these symptoms and lesions to those seen during experimental malignant hypertension supports the hypothesis that high blood levels of renin and aldosterone may have some pathogenic significance in clinical malignant hypertension.
TL;DR: These experiments, in conjunction with other observations, suggest that the hamster ovary develops approximately 10 large follicles on Day 1 but has an additional 25 follicles in reserve that can be stimulated if increased amounts of FSH are available.
Abstract: Hamsters injected with 30 IU of pregnant mares' serum (PMS)1 on Day 1 of the estrous cycle ovulated an average of 70 eggs, with the duration of ovulation and cycle length slightly prolonged. If one ovary was removed at the time of PMS treatment, the remaining ovary ovulated 34.8 eggs. The injection of 30 IU PMS at Day 2 or 3 lengthened the estrous cycle to 6 and 7 days, respectively, and resulted in the ovulation of approximately 45 ova. After similar treatment at Day 4, only 10 eggs were ovulated on the very next morning, but 56 eggs were released at the following cycle. These experiments, in conjunction with other observations, suggest that the hamster ovary develops approximately 10 large follicles on Day 1 but has an additional 25 follicles in reserve that can be stimulated if increased amounts of FSH are available. In the event that PMS is injected after Day 1, the normally developing follicles eventually become atretic, thus limiting final maturation to the reserve follicles.
TL;DR: The prolactin preparation causes a slight but significant increase in oxygen consumption in the presence of glucose and the ability of the preparation to stabilize with time the burst inoxy consumption seen upon add...
Abstract: The glucose uptake, net gas exchange, lactic acid production, oxygen consumption (in the presence of various carbon compounds) and free fatty acid release by rat epididymal adipose tissue in vitro have been measured in the presence of a prolactin preparation (0.2–1.0 mg/ml) alone and in combination with insulin or Adrenalin. Glucose uptake and net gas exchange are stimulated by this pituitary preparation in a manner that mimics the action of insulin. Both these processes may be stimulated further by the concomitant addition of insulin and, in the case of net gas exchange, the effect is synergistic. The prolactin preparation diminishes the production of lactic acid by the tissue and counteracts the action of insulin or Adrenalin in stimulating the formation of this metabolite. The prolactin preparation causes a slight but significant increase in oxygen consumption in the presence of glucose. More striking is the ability of the preparation to stabilize with time the burst in oxygen consumption seen upon add...