Showing papers on "Corticosterone published in 1975"

Changes in blood hormone levels during the immune response.

Abstract: Injection of three different antigens into rats or mice led in the course of several days to about a threefold increase in serum corticosterone levels and concommitantly to a decrease in thyroxine (rats). In view of the known immuno-suppressive effect of the glucocorticoids the possibility is considered that the endocrine changes induced during the immune response could significantly modulate the subsequent character of the immune response, e.i. magnitude, duration and lymphoid cell proliferation, however, a more complete pattern of hormonal variations and their cause needs to be established. These findings while admittedly preliminary, suffice to provide an indication of a temporal pattern of hormonal change during the immune response which could be important in immunoregulation.

Stress response patterns of plasma corticosterone, prolactin, and growth hormone in the rat, following handling or exposure to novel environment.

Abstract: Corticosterone, prolactin, and growth hormone responses to 5 s of handling or 3 min of novel environment were compared in rats at crest and trough of the diurnal adrenal rhythm 0, 5, 15, 30, and 60 min after stimulation. All hormones responded to stimulation, corticosterone and prolactin with a dramatic rise, and growth hormone with a precipitous fall. Resting corticosterone levels evidenced the expected diurnal variation, and prolactin but not growth hormone also showed a baseline diurnal variation of small magnitude at the times studied. Growth hormone response characteristics were unaffected by time of day or type of stimulation. Both corticosterone and prolactin response profiles differed at both times of day and following both types of stimulation. Corticosterone and prolactin levels were highly correlated and each was negatively correlated with growth hormone levels. This study confirms that hormone responses to stress are complex and depend not only on the stimulus but the context of stimulation.

Maternal and foetal corticosterone levels during late pregnancy in rats.

Abstract: Adrenal and plasma corticosterone levels were determined in rat foetuses and in intact or adrenalectomized mothers during late pregnancy. Foetal adrenal and plasma corticosterone concentrations reached a peak on day 19 of pregnancy, while maternal plasma corticosterone increased on day 18 and remained high until parturition. From day 18, mothers adrenalectomized on day 14 had corticosterone levels similar to those of intact pregnant rats. At every stage of gestation (except day 21) plasma corticosterone levels were higher in the foetuses than in the mothers. The corticosterone concentration in the maternal plasma correlated with the number of live foetuses during the last 3 days of gestation. These results suggest that corticosterone can cross the placenta from foetus to mother as early as day 18 and that the foetus contributes to the maternal corticosterone pool after day 18.

Increased rate of response of the pituitary-adrenal system in rats adapted to chronic stress.

Abstract: The response and adaptation of the pituitary-adrenal system to chronic stresses was investigated. These included individual caging, confinement, and exposure to cold for varying periods of time. Studies were carried out demonstrating that during the period of adaptation when plasma corticosterone concentrations returned toward their prestress level despite continued exposure to the stressor, the animals responded to additional stimuli of ether for 1 min, a saline injection, or release from confinement with a faster increase (within 2.5 min) in plasma corticosterone than controls (10 min). It is concluded that during adaptation to a chronic stress the pituitary-adrenal system is not inhibited by the circulating steroid level but is actually hypersensitive to additional stimuli.

The ontogeny and regulation of corticosteroid secretion by the ovine foetal adrenal.

Abstract: Adrenal glands of foetal sheep of 40 days gestation to term were incubated with and without ACTH or an increased [K-+]. With ACTH, the 40 day foetal adrenal was capable of producing more cortisol and aldosterone per g body weight than was the term adrenal. ACTH was a potent stimulus to aldosterone and cortisol production in foetuses aged 60-90 days, and this effect declined significantly in the 91-120 day period. An increased [K-+] was stimulatory to aldosterone production only after 120 days gestation. Peripheral blood levels of aldosterone, corticosterone, cortisol, 11-deoxycortisol and 11-deoxycorticosterone were measured in foetuses 60 days to term and the levels of aldosterone and cortisol were significantly lower in 90-120 day foetuses than in the younger or older ones. Direct adrenal vein cannulation proved all five steroids to be secretory products of the foetal adrenal.

Inhibition of replication of normal adrenocortical cells in culture by adrenocorticotropin.

Abstract: Adrenocorticotropic hormone (ACTH) inhibited [3H]thymidine incorporation in normal adrenocortical cells of adult rats in culture, with a concomitant increase in corticosterone production and a characteristic retraction of cells. Both dibutyryl cyclic AMP and an analog of ACTH, which produces virtually no cyclic AMP, inhibited DNA synthesis and stimulated steroid production. ACTH inhibited the proliferation of adrenocortical cells obtained from suckling rats as well as the cells obtained from the capsular tissue of adult rat adrenal glands, whereas insulin caused a stimulation of DNA synthesis. These results suggest that the major role of ACTH is to induce the transformation of the undifferentiated cells of the adrenal gland into functional fasciculata cells and that the proliferation of adrenocortical cells may be under control of factors other than ACTH.

Glucocorticoid and mineralocorticoid receptors in gut mucosa.

Abstract: Both glucocorticoid and mineralocorticoid hormones are known to be involved in the physiology and pathophysiology of the gastrointestinal tract. Studies on the mechanism of action of steroid hormones indicate an initial obligatory step of binding to stereospecific receptor proteins in the cytoplasm of target tissue cells. Mucosal cells from the gastrointestinal tract of adrenalectomized, gonadectomized rats contain cytoplasmic glucocorticoid receptors which bind tritiated dexamethasone with an affinity (Kdiss4C) of approximately 10(-8)M. The concentration of glucocorticoid receptors per unit cytoplasmic protein is in order duodenum greater than jejunum greater than ileum=stomach greater than colon, and their affinity for steroid hormones is in order dexamethasone greater than corticosterone greater than deoxycorticosterone=aldosterone. No glucocorticoid receptors could be demonstrated in esophageal mucosal cells. Binding sites for tritiated aldosterone, with affinity characteristics appropriate for physiological mineralocorticoid receptors, were demonstrated in duodenum, jejunum, ileum and colon. No similar sites could be shown in the mucosa of the gastric antrum.

Diurnal variations in plasma corticosterone and growth hormone as corrlelated with regional variations in norepinephrine, dopamine and serotonin content of rat brain.

Abstract: Statistically significant diurnal variations in plasma growth hormone (GH) were found to occur in handled male rats. Peak GH values (at midday) appeared to be inversely correlated with the diurnal pea

Binding of glycyrrhetinic acid to kidney mineralocorticoid and glucocorticoid receptors.

Abstract: Whether the mineralocorticoid effect of glycyrrhetinic acid is mediated by the adrenal glands or is due to a direct action on the renal tubule remains controversial. The affinity of glycyrrhetinic acid for mineralocorticoid receptors has been studied by several types of competition experiments. When rat kidney slices were incubated with 2 × 10-9 M [3H]aldosterone, glycyrrhetinic acid (2 × 10-5 M) was able to compete with aldosterone for the cytosolic receptor and to decrease the formation of a chromatin-[3H] aldosterone- receptor complex. In cytosol, in vitro, 6 × 10-4 M glycyrrhetinic acid was able to inhibit aldosterone binding by 70%, whereas the same dose produced only a 20% inhibition of dexamethasone binding. The apparent KDIss of glycyrrhetinic acid for the mineralocorticoid receptor was 2 × 10-6 M. That glycyrrhetinic acid appeared to compete mainly with mineralocorticoid receptors was confirmed by sedimentation in sucrose gradients: [3H]Aldosterone specifically bound to an 8 S peak was displaced ...

Effects of acute and chronic stress on plasma corticosterone levels in the pregnant and non-pregnant mouse

Abstract: Plasma corticosterone levels were measured in the pregnant and non-pregnant mouse after acute and chronic stress. Acute surgical stress in the non-pregnant mouse increased plasma corticosterone from a mean resting level of 2-3 to 50-6 mug/100 ml 1 h after operation. By 24 h after operation, levels had fallen back to 7-6 mug/100 ml. In the pregnant mouse an acute surgical stress on day 14 or pregnancy increased plasma corticosterone levels to 525 mug/100 ml 1 h after surgery from a resting value of 80 mug/100 ml, with a return to resting levels by 24 h. During the chronic stress of 24 h restraint, plasma corticosterone levels in the non-pregnant mouse reached a peak (81-0 mug/100ml) 1 h after the start of restrain and were still raised (mean 24-0 mug/100 ml) after 24 h. In the pregnant restrained mouse a peak value of 733 mug/100 ml was seen at 1 h, with levels maintained at around 500-600 mug/100 ml during the next 16 h of restraint. Increased levels of 268 mug/100 ml were still present at 24 h. After the chronic stress of 24 h food deprivation, plasma corticosterone levels in the non-pregnant and pregnant mice were raised after 7 h to levels slightly lower than those observed in the restrained groups, and at 24 h levels in the respective restrained and food-deprived groups were similar, suggesting that food deprivation is a powerful chronic stressor in the mouse. During chronic stress in the pregnant mouse where plasma corticosterone levels of around 600 mug/100 ml were maintained fro some hours, protein binding studies indicated that 10 mug/100 ml was free, unbound corticosterone. The physiological and pathological consequences of such high levels of free corticosterone during stress in pregnancy are discussed.

Effect of Adrenocortical Hormones on Activity of the Serotoninergic System in Limbic Structures in Rats

Abstract: A single dose of corticosterone (1 mg/kg b.w. i.p.) increased the 5-hydroxytryptamine (5-HT) content in the mesencephalon, amygdala and hypothalamus. The maximum was observed at 15 min following admin

Corticosterone-induced changes in hypothalamic corticotropin-releasing factor (CRF) content after stress.

Abstract: Central and peripheral humoral responses of the adrenocortical system were measured for 2 h after the application of several stimuli. Two min after the onset of the stressesof shamadrenalectomy or laparotomy with intestinal traction there was a 4-6-fold increase inhypothalamic CRF content as compared to control content. This is the usual CRF response to stress. In contrast, after adrenalectomy or manipulation of the pedicles of adrenal glands, CRF content at 2 min was only slightly increased above baseline values. This finding suggests that touching the adrenal vascular and nervous supply results in a direct neural input to the hypothalamus that is qualitatively different from most other stimuli. At times later than 2 min after stress, when plasma corticosterone levels rise in the intact rat, the patterns of CRF and ACTH responses that were observed after adrenalectomy were determined by whether corticosterone replacement therapy was given. Without corticosterone replacement, the CRF and ACTH responses to...

Control of aldosterone secretion in the spontaneously hypertensive rat.

Abstract: Adrenal secretion rates of aldosterone, corticosterone, and deoxycorticosterone were studied sequentially in the spontaneously hypertensive rat and the normotensive Kyoto Wistar rat. Steroid secretion was studied at three different ages: 7-8, 11-13, and 22-25 weeks. Also, peripheral plasma levels of aldosterone and plasma renin activity were determined in both the spontaneously hypertensive and the normotensive rats at 7-8 weeks of age. Aldosterone secretion was elevated markedly in dexamethasone-morphine-treated spontaneously hypertensive rats at both 7-8 and 11-13 weeks of age but was not significantly different from control in 22-25-week-old spontaneously hypertensive rats. No statistically significant differences in corticosterone or deoxycorticosterone secretion rates were observed between the spontaneously hypertensive rats and the normotensive Kyoto Wistar controls; however, the data suggested that dexamethasone did not suppress adrenocorticotropic hormone in the 7-8- and 11-13-week-old spontaneously hypertensive rats to the same extent that it did in the normotensive Kyoto Wistar rats. Therefore, aldosterone secretion was reexamined in acutely hypophysectomized 7-8-week-old rats to eliminate completely the influence of the anterior pituitary; no differences in aldosterone, corticosterone, or deoxycorticosterone secretion rates were observed between hypophysectomized spontaneously hypertensive rats and normotensive Kyoto Wistar rats. Moreover, aldosterone secretion in the hypophysectomized 7-8-week-old spontaneously hypertensive rats was reduced markedly compared with that in the intact 7-8-week old spontaneously hypertensive rats, thus confirming the importance of the pituitary in these animals. Determinations of peripheral plasma aldosterone concentration and plasma renin activity in unstressed 7-8-week-old spontaneously hypertensive and normotensive rats revealed that both parameters were depressed significantly in the spontaneously hypertensive rats. Thus, the present data indicate that the renin-angiotensin-aldosterone system is suppressed in the spontaneously hypertensive rat but do not suggest that the system is critically involved in the hypertensive process in these animals

The relation between maternal restraint and food deprivation, plasma corticosterone, and induction of cleft palate in the offspring of mice.

Abstract: The blood level of corticosterone was measured in mice following the injection on day 14 of pregnancy of a dose of corticosterone sufficient to cause a low frequency of cleft palate in the fetuses. This was compared with the blood levels present during maternal restraint and food deprivation that produced a similar frequency of cleft palate. The mean blood level over the 24 h following injection of corticosterone was 660 mug/100 ml, and during a similar period of restraint was 485 mug/100 ml. Other mice were subjected either to restraint or food deprivation for 24 h beginning day 14 of pregnancy, the plasma corticosterone levels measured during that time, and the frequency of cleft palate in late fetuses compared with the individual plasma corticosterone levels during treatment. There was a significant (P less than 0.025) correlation between high maternal corticosteroid levels and the frequency of cleft palate in the offspring of the restrained mice but not in the food-deprived animals. It is suggested that in some stressed mice endogenous plasma corticosterone can reach levels sufficient to account for the development of cleft palate.

Circadian rhythm of tyrosine hydroxylase induction by short-term cold stress: modulatory action of glucocorticoids in newborn and adult rats.

Abstract: The trans-synaptic induction of tyrosine hydroxylase [tyrosine 3-monooxygenase; EC 1.14.16.2, L-tyrosine, tetrahydropteridine: oxygen oxidoreductase (3-hydroxylating)] in adrenal medulla and sympathetic ganglia by short-term (1-2 hr) cold stress (4 degrees) exhibits a circadian rhythm which seems to be causally related to the diurnal changes in adrenal glucocorticoid synthesis. In induction is maximal during the morning hours, when plasma corticoid concentrations (reflecting corticoid synthesis in the adrenal cortex) are minimal. In contrast, initiation of tyrosine hydroxylase induction in sympathetic ganglia is only possible in the afternoon. These observations suggest that tyrosine hydroxylase inducibility in the adrenal medulla is optimal during periods of low corticoid synthesis (the adrenal medulla is exposed to excessively high corticoid concentrations directly originating from the adjacent cortex), whereas in sympathetic ganglia an induction is only possible during the period of high plasma corticoid concentrations. This assumption is supported by the observation that in the first postnatal weeks, when the pituitary--adrenocortical system is not yet operating and plasma corticoid concentrations are low, initiation of tyrosine hydroxylase induction in the adrenal medulla is possible at any time of the day, whereas in sympathetic ganglia it is not possible at all. However, after administration of glycocorticoids initiation of tyrosine hydroxylase induction by short-term cold stress is also possible in newborn animals and in adults during the morning hours. The importance of glucocorticoids as modulators for the initiation of trans-synaptic tyrosine hydroxylase induction can also be deduced from the observation that in sympathetic ganglia kept in organ cultures and induction of the hydroxylase by cholinomimetics is only possible when glycocorticoids are added to the culture medium.

Estimation of aldosterone, 11-deoxycorticosterone, 18-hydroxy-11-deoxy-corticosterone, corticosterone, cortisol and 11-deoxycortisol in human plasma by gas-liquid chromatography with electron capture detection.

Abstract: A method for determining the plasma concentrations of six major corticosteroids, aldosterone, 18-hydroxy-11-deoxycorticosterone (18-OH-DOC), corticosterone, deoxycorticosterone (DOC), cortisol and 11-deoxycortisol using gas-liquid chromatography with electron capture detection is described. Esterification of suitable derivatives of these compounds with heptafluorobutyric anhydride (HFB) allowed detection of quantitities of steroid, ranging from 0-3 pg for androstenetrione HFB (from cortisol) to 2-3 pg for corticosterone HFB. No detectable reagent blank was obtained for any compound when water was used instead of plasma and this was also the case when plasma from an adrenalectomized subject was analysed, with the exception of 18-OH-DOC where a reproducible but negligibly small blank occurred. Coefficients of variation for replicate determinations ranged from 8% for corticosterone to 17% for aldosterone. Concentrations in a series of normal human plasma samples were as follows: aldosterone, 4-0- 18-0 ng/100 ml; 18-OH-DOC, 20-16- ng/ml; corticosterone, 0-08 - 0.-80 mug/100 ml; DOC, 2-8 - 16-0 ng/100 ml; cortisol, 2-5 - 10-0 mug/100 ml; and 11-deoxycortisol, 40-0 - 400-0 ng/100 ml. When seven normal subjects were treated with dexamethasone concentrations of DOC, cortisol and 11-deoxycortisol fell to below the limit of the normal range, those of 18-OH-DOC and corticosterone were at the lower end of the normal range while the concentration of aldosterone was not significantly affected.

Behavior of eosinophil leukocytes in acute inflammation. I. Lack of dependence on adrenal function.

Abstract: Acute infection is accompanied by a characteristic reduction in circulating eosinophils. This study examined the generally held assumption that the eosinopenia of infection is a manifestation of adrenal stimulation. Trichinosis, Escherichia coli pyelonephritis, and early subcutaneous pneumococcal abscess were used as experimental infections of limited severity. Trichinosis is associated with eosinophilia, but pyelonephritis and pneumococcal infection produce eosinopenia. An assay for serum corticosterone was developed that is sufficiently sensitive to be performed with the small volumes of blood obtained sequentially from individual mice. The corticosterone response to trichinosis fits the sterotyped reaction previously reported for several other bacterial, viral, and rickettsial infections. The peak concentrations of corticosterone in serum from mice with trichinosis was approximately twice normal and occurred at the onset of clinical illness. Serum corticosterone levels gradually declined to the normal range over the next several days. E. coli pyelonephritis produced a similar adrenal response, although the peak serum corticosterone caused by pyelonephritis was less than the serum corticosterone occurring during the first peak of eosinophilia during trichinosis. Infection of a subcutaneous air pouch with penumococci produced eosinopenia within 6 h after inoculation, but there was no rise in serum corticosterone during the first 12 h of the pneumococcal infection. In addition, the eosinopenic response produced by a 12-hpneumococcal abscess occurred mice adrenalectomized 1-4 days before infection with pneumococci. The eosinopenia of acute infection cannot be ascribed to adrenal stimulation.

Adrenal steroidogenesis in the spontaneously hypertensive rat (SHR).

Abstract: Adrenal vein catheterizations were done in SHR and control rats at different ages during the development of hypertension. All SHR became hypertensive by 15 weeks of age. The secretion rate of aldosterone was significantly reduced at 8 weeks of age, 18-hydroxy-11-deoxycorticosterone (18-OH-DOC) at 12 weeks of age, deoxycorticosterone (DOC) at twenty weeks of age, and corticosterone (B) at 12 and 20 weeks of age. Secretion data suggest either an enzyme block, or increased conversion of known steroids to an unknown steroid product. Reduced secretion of corticosterone could explain the adrenal hyperplasia observed in SHR which may be important to the development of hypertension in these animals.

Ontogenesis of the alpha-MSH, beta-MSH and ACTH cells in the foetal hypophysis of the rat. Correlation with the growth of the adrenals and adrenocortical activity.

Abstract: Pituitary sections from 15 to 21 day-old rat foetuses have been studied with the immunofluorescence technique, using antibodies anti α-MSH, anti β-MSH and anti β (1–24) ACTH. The first ACTH cells appear on day 17 of pregnancy in the pars distalis of the hypophysis and only on day 18 in the pars intermedia. β-MSH cells have been observed on day 16 in the pars anterior and on day 17 in the pars intermedia, while α-MSH cells appear only on day 18 and exclusively in the pars intermedia. The cytodifferentiation of the β-MSH and ACTH cells occurs in the pars intermedia with about a 24 hour delay in comparison to that of the pars distalis. The first revealed cells are always located in the posterior half of the pituitary gland. The corticostimulating activity of the hypophysis has been tested with the fluorescence intensity of the corticotrophs, the adrenal weight, the adrenal content in corticosterone and the plasma corticosterone level. The fluorescence of the corticotrophs increases on day 18, shows a maximum on day 19 and decreases until term. The adrenal weight rises regularly between day 16 to day 20, thereafter the increase subsides. Adrenal and plasma corticosterone concentrations reach a peak on day 19 of pregnancy. These data suggest that hypophyseal corticostimulating activity is very high between days 18 and 19 and decreases between days 19 and 21.

Effect of ACTH and Histamine Stress on Serum Corticosterone and Adrenal Cyclic AMP Levels in Immature Rats

Abstract: Adrenal cAMP and plasma corticosterone levels were determined in pre-weanling rats subjected to treatment with either ACTH (50 mU* rat) or histamine dihydrochloride (0.2 mg*g body wt). ACTH injection elevated both serum corticosterone and adrenal cAMP levels on all days tested. However, the ACTH-induced elevation of adrenal cAMP and serum corticosterone both diminished steadily from day 2 to day 8 and then increased from day 8 to day 16. Histamine injection resulted in elevated serum corticosterone levels in a pattern similar to that of the corticosterone response to ACTH. However, histamine injection did not result in any significant increase in adrenal cAMP from day 2 to day 10. From day 12 to day 16 the adrenal cAMP concentration rose steadily in parallel with the serum corticosterone levels. These results indicate: (1) that a functional, ACTH-sensitive adenyl cyclase system is present in the adrenal gland of the immature rat, (2) that the responsiveness of this system diminishes during the first postn...

Identification of aldosterone-induced proteins in the toad's urinary bladder.

Abstract: Aldosterone (the 8,11-hemiacetal 0f 11beta,21-dihydroxy-3,20-dioxo-4-pregnen-18-al) markedly stimulates sodium transport in a number of epithelial tissues. We have attempted to determine whether aldosterone induces the synthesis of specific protein(s) in the course of its action upon the toad urinary bladder. Paired hemibladders were incubated in media containing either [3H]methionine or [35S]methionine; aldosterone in physiologic concentrations was added to one bath and, after incubation, the intact "mitochondria-rich" (MR) and "granular" (G) mucosal cells were isolated. The ratio (3H/35S) was used to identify proteins whose synthesis was induced in the mucosal cells of the steroid-treated bladders. Using exclusion gel chromatography and isoelectric focusing, we identified several aldosterone-induced proteins in the supernatant (105,000 x g) fraction of the MR cell. None was evident in this fraction of the G cell. These proteins have apparent molecular weights ranging from 17,000 to 38,000 and the isoelectric point of the major component is 4.5. Corticosterone (11beta,21-dihydroxy-4-pregnene-3,20-dione) induced the synthesis of proteins in the G cells, but none of these proteins was similar in molecular weight to the aldosterone-induced proteins in the MR cell. Our findings support the hypothesis that aldosterone induces the synthesis of specific proteins and indicate that, in this tissue, these proteins are synthesized by the MR cell.

Impairment of conditioned active avoidance in adult rats given corticosterone in infancy

Abstract: Intensive corticosterone treatment given to rats during the 1st postnatal week irreversibly decreases DNA accumulation in the cerebrum and cerebellum. After such hypercorticism in infancy rats were tested as adults in 2 conditioned active avoidance tasks. In comparison with litter-mate controls, the treated rats were impaired in the acquisition of 2-way active avoidance but not in the acquisition of 1-way active avoidance. These data are consistent with other observations suggesting a hyperresponsiveness or hyperemotionality following corticosterone treatment in infancy.