Showing papers on "Steroid biosynthesis published in 1968"

The syndrome of congenital adrenocortical unresponsiveness to ACTH. Report of six cases.

Abstract: Extract: Six patients with the syndrome of congenital adrenocortical unresponsiveness to ACTH are reported This syndrome is characterized by feeding problems early in life, hypoglycemic episodes and hyper-pigmentation of the skin (table I) Blood pressure and levels of electrolytes in serum were normal (table II) PPD and histoplasmin skin tests were negative, while antibodies to adrenal, thyroid, and gastric tissues were undetectable Urinary excretion of 17-hydroxycorticosteroids and cortisol production rates were low and did not respond to administration of ACTH (table III) While receiving a low sodium diet, the patients were able to conserve sodium (figs 2, 3 and 4) and to increase the rate of aldosterone secretion (tables IV and V) In one case, adrenal pathology showed a normal zona glomerulosa with atrophy of the zonae fasciculata and reticularis This isolated deficiency in cortisol secretion is not due to a defect in pituitary function or a deficiency of one of the enzymes directly involved in steroid biosynthesis The most probable pathogenesis is an abnormality at the site (or one of the sites) of ACTH action on cortisol biosynthesis Speculation: It is probable that some young infants in whom a diagnosis of Addison's disease is made do, in fact, have the syndrome of congenital adrenocortical unresponsiveness to ACTH Studies of cortisol secretion rates prior to and during ACTH administration and a determination of aldosterone secretion rates while receiving normal and low salt diets will permit differentiation of the two disorders

Studies on interstitial cells in tissue culture. II. Steroid biosynthesis by a clonal line of rat testicular interstitial cells.

Abstract: A stable, clonal, monolayer culture has been established from a transplantable tumor of the testicular interstitial cells of rat. The original culture contained 2 distinct cell types. An epithelial-type clone isolated from this culture secretes a high level of steroid hormones, is nearly diploid and is functionally stable through extended serial subcultures. The major steroids synthesized by this clone are 20α-hydroxypregn-4-en-3-one and progesterone. Androgenic steroids could not be detected in significant amounts. A second clone from the original culture was composed of a fibroblasttype cell and showed no steroidogenic capacity. (Endocrinology 82: 614, 1968)

Organization and activity in the pre- and postovulatory follicle of Necturus maculosus.

Abstract: The established follicle envelope of Necturus maculosus consists of a layer of follicle cells (granulosa) surrounding the developing oocyte, a layer of theca comprised of connective tissue cells, fibers, and matrix, and a layer of serosal cells. The changes in shape and fine structure of these layers during differentiation accompanying oogenesis are described. The cells and capillaries of the follicle envelope are engaged in an extensive pinocytotic activity, the details of which are described. We used cytochemical techniques to analyze the activity of the follicle envelope with respect to lipid accumulation and alkaline phosphatase activity. Radioautographic results indicate that cells of the follicle envelope are capable of incorporating tritium-labeled uridine and amino acids at certain times during oocyte growth. A comparative analysis was made of the soluble proteins in follicle envelopes isolated from immature oocytes and of those in follicle envelopes isolated from nearly mature oocytes and in postovulatory follicles. After the oocyte is ovulated, the cells of the follicle envelope are converted into a postovulatory follicle. The cells of the postovulatory follicle undergo further differentiation resulting in their becoming actively engaged in the formation of a secretion, the details of which are described at the electron microscope level. Analysis of the postovulatory follicle by thin-layer chromatography and cytochemistry demonstrated the presence of a wide variety of lipid substances and the possible presence of steroid. That the postovulatory follicle may be engaged in steroid biosynthesis is also suggested by studies involving the demonstration of 3 beta-hydroxysteroid dehydrogenase activity with cytochemical techniques applied to frozen sections and to soluble proteins separated by gel electrophoresis.

Steroid Hormone Formation in the Human Ovary: V. Synthesis of Progesterone in Vitro in Corpora Lute a During the Reproductive Cycle

Abstract: Progesterone synthesis in vitro and the influence of exogenous gonadotropin were studied in slices of 50 individual human corpora lutea removed at different times during the reproductive cycle. Radioactive progesterone synthesis (dpm) was assessed by incorporation of radioactivity from acetate-1-14C. The progesterone contained in corpora lutea and formed in vitro from endogenous precursors (μg) was measured spectrophotometrically by its absorption of ultraviolet light. All luteal phase corpora lutea synthesized progesterone in vitro as measured by these 2 parameters (dpm and μg). No radioactive progesterone synthesis (dpm) from acetate-1-l4C was found in 3 corpora lutea obtained after onset of menses, although 2 of the 3 specimens synthesized progesterone (μg) from endogenous precursors. Corpora lutea from all phases of pregnancy and up to 4 days post partum synthesized progesterone in vitro. The capacity for steroid biosynthesis during the post-par turn period appeared to decline gradually when ...

Steroid biosynthesis in vitro by transplantable interstitial cell tumor of mice. I. Identification and quantitative determination of the metabolites and intracellular distributon of the enzymes related to testosterone formation.

Abstract: Androgen producing activity of a transplanted tumor of mice, originating in the testicular interstitial cell, was biologically confirmed by the fact that the sex-accessory organs of the tumor-bearing mice did not show any decrease in weight even after removal of the testicular glands. After slices of the testicular interstitial cell tumor which had been transplanted to the mice were incubated in vitro with relabeled pregnenolone and progesterone, respectively, as substrate, not only 17α-hydroxyprogesterone, androstenedione and testosterone, but also the corticosteroids such as deoxycorticosterone, 18-hydroxy-ll-deoxycorticosterone, corticosterone and 11-deoxycortisol were isolated as the metabolites and identified, suggesting that this tumor retained enzyme functions of producing adrenocorticoids as well as androgen. Furthermore, progesterone which was administered as a substrate was catabolized into 20α-and 20β-hydroxypregn-4-en-3-one and 6β-hydroxyprogesterone. The enzyme activities related to androgen ...

Heterogeneity of induced testicular interstitial cell tumors of mice as evidenced by steroid biosynthetic enzyme activities.

Abstract: Quantitative enzyme studies (17 α -hydroxylase, 17,20-desmolase, 21-hydroxylase, and 20 α -hydroxydehydrogenase), using as a source of enzyme small fragments (25–48 mg) of estrogen-induced testicular interstitial cell (Leydig cell) tumors of mice and their first generation transplants in castrate male isogeneic hosts, show rather conclusively that such tumors are composed of heterogeneous populations of hormone-producing cells. Our data supported the original concept that, during tumor induction or shortly thereafter, several enzyme systems involved in steroid biosynthesis in Leydig cells decrease in an apparently random fashion. However, it appeared evident that at least in certain neoplastic interstitial cells the activity of 20 α -hydroxydehydrogenase, an enzyme whose functional significance has not yet been clearly established, increased significantly.

Quantitative histological distribution of isocitric dehydrogenase in the rat adrenal with effects of adrenocorticotropin, and determination of the enzyme in microgram samples of tissue.

Abstract: A microfluorometric adaptation of the spectrophotometric method for determination of isocitric dehydrogenase activity was developed for use with μg samples of tissue, e.g., microtome sections. The method was based on measurement of NADPH formed when NADP oxidizes isocitrate. A study was carried out of the quantitative histological distribution of the enzyme in the rat adrenal, and the influence of single subcutaneous injections of ACTH insaline solution (25 mg/kg), as well as of injections (10 mg/rat) twice daily for 5 days of ACTH in gel. These treatments had little effect on the activity or its localization, which was maximal in the reticularis and the fascicular-reticular border zone. The relationship of the isocitric dehydrogenase activity to formation of NADPH for steroid biosynthesis in the adrenal was considered. (Endocrinology 83: 596, 1968)