Circulating Steroid Levels Research Articles

A developmental study of progesterone, corticosterone, cortisol, and cortisone in the adrenal glands of the embryonic chick

Pairs of adrenal glands were removed from embryonic chicks at 2-day intervals between 9 and 21 days of incubation. Four corticosteroids (progesterone, corticosterone, cortisol, and cortisone) were separated by column chromatography and their concentrations were determined using the competitive protein-binding assay of Murphy [(1967) J. Clin. Endocrinol. Metab. 27, 973–990]. Further identification of cortisol in embryonic chicks was carried out using thin layer and paper chromatography followed by the double isotope assay. Total corticosteroid/pair adrenal glands rose from 9 ng at 9 days to a peak of 38 ng at 15 days. The concentration declined to 21 ng at 19 days and then rose again at hatching. Over the 12-day period studied corticosterone accounted for one third of the total adrenal corticosteroids measured. At hatching corticosterone and its precursor, progesterone accounted for 71% of the total, indicating establishment of the adult pattern of predominance of corticosterone. This report, along with our previous paper [(1974) Gen. Comp. Endocrinol. 24, 364–372], provides base line normal gland and circulating steroid levels. It emphasizes that several corticosteroids are being synthesized and secreted during embryonic development.

Effects of toxaphene on hepatic enzyme induction and circulating steroid levels in the rat.

Rats were given a single dose of toxaphene (120 mg/kg, equivalent to 1/2 LD50) and sacrificed at 1, 5, and 15 days. Liver weight and hepatic microsomal enzyme activity were increased at day 5 and 15. The level of plasma testosterone was significantly decreased at day 15. In a second experiment rats were given 2.4 mg/kg daily and sacrificed at 1, 3 and 6 months. Liver weight and microsomal enzyme activity were significantly increased over controls; enzyme activity was, however, decreasing by the end of the experiment. Plasma testosterone levels were not affected. It is concluded that enhanced hepatic enzyme induction causes only a transient drop in circulating testosterone levels followed by a return to normal values.

Treatment of Prostatic Carcinoma with Various Types of Estrogen Derivatives

3 therapeutic regimens for cancer of the prostate were evaluated in 24 patients. The patients received either 160 mg/month intramuscularly of polyestradiol phosphate (PEP; Estradurin), PEP plus 150 mcg/day ethinyl estradiol (PEP + EE), or 600 mg/day of estramustine phosphate (EMP; Estracyt). On the basis of 5-year survival rates, PEP + EE was found to be superior to PEP alone, while EMP could not be properly evaluated. Nonetheless, it appears that EMP may be valuable in advanced cases that are unresponsive to other estrogen therapies. As determined by their inhibitory effect on levels of circulating gonadotropins, circulating steroid levels and plasma prolactin and cortisol levels, EMP and PEP + EE exhibited stronger estrogenic effects than PEP alone, with EMP showing the greatest potency.

STUDIES ON THE PATTERN OF CIRCULATING STEROIDS IN THE NORMAL MENSTRUAL CYCLE

In an attempt to analyze the multiple changes and interactions in circulating steroid levels in the peri-ovulatory and peri-menstrual periods, the plasma levels of immunoreactive luteinizing hormone (LH), progesterone and unconjugated pregnenolone, dehydroepiandrosterone, testosterone, oestradiol and oestrone were assayed daily during a complete cycle in 17 normally menstruating women. In 14 of the 17 subjects studied androstenedione and unconjugated dihydrotestosterone were also estimated. The day of the LH-peak and the first day of menstruation, respectively, were used to synchronize the peri-ovulatory and peri-menstrual plasma levels of the various steroids. With the exception of dehydroepiandrosterone and dihydrotestosterone, the plasma levels of all steroids exhibited significant, but different changes during the cycle. Testosterone levels showed a slight but significant increase around the LH-peak, whereas the levels of pregnenolone and androstenedione were higher in the post-ovulatory than in the pre-ovulation periods. The levels of oestradiol and oestrone, as well as the ratios of oestradiol to oestrone gradually increased from the low values observed in the early proliferative phase to pre-ovulatory peak values. The relationship between peaks of oestradiol and oestrone and that of LH exhibited great individual variation. The same was true for the individual oestradiol to oestrone ratios. The combination of several steroidal signals did not improve the predictive value of the analyses. However, an increase of individual progesterone values by at least 0.35 ng/ml from the day preceding the LH-peak to the day of the LH-peak was observed in 13 of the 17 subjects. It is suggested that for the early detection of the LH surge and prediction of the subsequent ovulation daily assays of plasma progesterone are of more value than the assay of the other steroids investigated.

Withdrawal bleeding and luteinizing hormone secretion following progesterone in women with amenorrhea

An acute rise in plasma luteinizing hormone on the second day following an intramuscular injection of progesterone in women with secondary amenorrhea is described and correlated with withdrawal bleeding following progesterone and changes in gonadotropin secretion and ovulation in response to clomiphene. We propose that the progesterone withdrawal test is, in fact, a test of the ability of the hypothalamic-pituitary unit to respond to changes in circulating steroid levels.

Variation in adrenal cortical hormones within physiologic ranges, stress and interferon production in mice.

SummaryBoth stress and pharmacologic levels of adrenal cortical hormones have been reported to suppress the synthesis of interferon. We measured interferon in mice 6 hours after intravenous injection of NDV and related interferon titers to plasma corticosterone levels. The stress of repeated random electric shocks preceded by a warning buzzer during interferon production did not alter the response from that of controls; such stress administered for 5 hours prior to virus inoculation significantly enhanced interferon production. Administration of ACTH did not alter interferon response. Corticosterone administration adequate to produce high circulating steroid levels just greater than maximal attainable physiologic levels also did not alter response. All adrenalectomized mice had relatively higher interferon titers; however, neither prior stress nor partial corticosterone replacement therapy in any combination significantly altered interferon production. Administration of the virus itself produced an adrena...