Basal and HCG-stimulated testosterone production by interstitial cells of the Mongolian gerbil (Meriones unguiculatus)--II. Influence of glucocorticosteroids and steroidal precursors

The effects of ACTH on steroid metabolomic profiles in human adrenal cells

The adrenal glands are the primary source of mineralocorticoids, glucocorticoids, and the so-called adrenal androgens. Under physiological conditions, cortisol and adrenal androgen synthesis are controlled primarily by ACTH. Although it is well established that ACTH can stimulate steroidogenesis in the human adrenal gland, the effect of ACTH on overall production of different classes of steroid hormones has not been defined. In this study, we examined the effect of ACTH on the production of 23 steroid hormones in adult adrenal primary cultures and 20 steroids in the adrenal cell line, H295R. Liquid chromatography/tandem mass spectrometry analysis revealed that, in primary adrenal cell cultures, cortisol and corticosterone were the two most abundant steroid hormones produced with or without ACTH treatment (48  h). Cortisol production responded the most to ACTH treatment, with a 64-fold increase. Interestingly, the production of two androgens, androstenedione and 11β-hydroxyandrostenedione (11OHA), that were also produced in large amounts under basal conditions significantly increased after ACTH incubation. In H295R cells, 11-deoxycortisol and androstenedione were the major products under basal conditions. Treatment with forskolin increased the percentage of 11β-hydroxylated products, including cortisol and 11OHA. This study illustrates that adrenal cells respond to ACTH through the secretion of a variety of steroid hormones, thus supporting the role of adrenal cells as a source of both corticosteroids and androgens.

Urinary excretion of free progestins, androgens, and estradiol after injection of (1-24)ACTH in the Mongolian gerbil

Injection of a "long-acting" synthetic adrenocorticotrophin [(1-24)ACTH, 20 IU/animal] into Mongolian gerbils resulted in a 3.1 fold increase of urinary free testosterone excretion over 2 days. It was accompanied by an elevation of urinary free progesterone (2.1 fold), 17-hydroxyprogesterone (2.5 fold), DHEA (2.8 fold) and androstenedione (3.0 fold) excretion. Similarly, administration of human chorionic gonadotrophin (HCG, 100 IU/animal) increased urinary excretion of free testosterone (2.3 fold), progesterone (4.1 fold), 17-hydroxyprogesterone (2.9 fold), DHEA (4.6 fold), androstenedione (5.4 fold) and of estradiol (2.9 fold). Data presented in this work show that the measurement of urinary free steroid excretion represents a reliable index for the secretory activity of the adrenal-gonadal-axis, and that it may in some aspects be more practicable than the measurement of steroid plasma levels, especially in small laboratory animals, enabling us to monitor the excretion of various steroids over longer time periods without stressing the animals by handling/or blood sampling.

Urinary excretion of free glucocorticosteroids and testosterone in the Mongolian gerbil (Meriones unguiculatus): effects of long-acting corticotrophin and human gonadotrophin

1. Methods for the quantitative collection of 24-hr urines of small laboratory animals and for the measurement of urinary free glucocorticosteroids and testosterone are described. 2. Urinary glucocorticosteroids and testosterone were determined in 0.1-0.5 ml-aliquots of 1/100 diluted urines after kieselgur mini-column extraction. 3. Excretion of glucocorticosteroids and testosterone in undisturbed Mongolian gerbils was 329 and 13 ng/day, respectively. 4. Administration of long-acting (1-24)ACTH (20 IU/animal) increased glucocorticosteroid and testosterone excretion to about 2000 ng/day (glucocorticosteroids) and to about 30 ng/day (testosterone) over 3 days. 5. In animals injected with 100 IU/animal HCG, testosterone excretion was elevated to about 35-50 ng/day over 3 days. 6. As the results show, the measurement of urinary excretion of free glucocorticosteroids and testosterone is a reliable index of adrenal-gonadal function in the Mongolian gerbil. 7. Furthermore, in small laboratory animals, steroid measurements in 24-hr urines may be superior to determinations in plasma, since amounts of urinary steroid are relatively high and 24-hr urines can be collected over longer time periods without stressing the animals.

Testosterone secretion by Mongolian gerbil interstitial cells during short-term incubation depends on androgen precursors and serum proteins but not on gonadotrophins

Interstitial cells from the testes of the Mongolian gerbil have been used to investigate the effects of serum proteins on testosterone production stimulated by hCG and steroidal precursors. Short-term incubation of interstitial cells with progesterone or DHEA resulted in a rapid increase of testosterone secretion; this effect was even more pronounced in the presence of calf serum. On the other hand, addition of hCG (10 mIU) had no significant effect on testosterone release during the 30-min incubation. These results demonstrate that the magnitude of the steroidogenic response of short-term incubated interstitial cells is a complex function, mainly of precursor concentrations and binding capacities of serum proteins but not of gonadotrophins.

The influence of dehydroepiandrosterone on basal and gonadotrophin-stimulated testosterone secretion by Mongolian gerbil interstitial cells incubated or superfused in vitro

1. Testosterone secretion by Mongolian gerbil interstitial cells incubated in the absence of HCG linearly increased with cell concentration (1 x 10(5) cells: 0.6 ng/4 hr, 10 x 10(5) cells: 8.0 ng/4 hr). Addition of 100 mIU HCG resulted in a drastic increase of testosterone secretion which was linear between concentrations of 1 x 10(5) and 4 x 10(5) cells. 2. Compared to HCG-stimulated testosterone release, secretion was significantly higher by cells incubated with 60-100 ng DHEA. 3. During the 4-hr incubation period, 53-69% of added progesterone and 72-88% of added dehydroepiandrosterone (DHEA) were converted to testosterone by cells freshly prepared or stored for 1-3 days at 4 degrees C. On the other hand, prolonged storage at 4 degrees C resulted in a marked decrease of HCG-stimulated testosterone secretion. 4. Testosterone secretion by interstitial cells superfused in vitro increased with the length of HCG (100 mIU/ml) application from 0.08 to 0.22 ng/10(6) cells/min (10 and 60 min, respectively). A much faster and pronounced elevation was found when cells were stimulated with DHEA (200 ng/ml: 0.06-0.80 ng/10(6) cells/min, 0 and 20 min, respectively). 5. After interstitial cells have been stimulated with a DHEA (200 ng/ml) pulse for 30 min and then superfused with medium only for an additional 30 min, testosterone secretion remained significantly elevated and could not be further stimulated by superfusing medium which contained as much as 100 mIU/ml HCG.