Dissociation of plasma and urinary steroid values after application of stressors, insulin, vasopressin, ACTH, or dexamethasone in the Mongolian gerbil

Abstract

The amounts of cortisol and testosterone in the plasma or urine of Mongolian gerbils exposed to stress factors or treated subcutaneously with insulin (2 IU), vasopressin (1 IU), ACTH (6 IU) or dexamethasone (50 micrograms) were determined. Increased plasma cortisol was observed in animals stressed by ether anesthesia or immobilisation (1-4 hours), or treated with insulin, vasopressin or ACTH. Cortisol levels were reduced after dexamethasone administration. Plasma testosterone was elevated in animals stressed by ether anesthesia or handling plus seizure; no other treatment altered testosterone levels. An augmented cortisol excretion, which lasted one day, occurred in gerbils immobilised for one as well as for four hours. A much more prolonged stimulation of cortisol excretion, lasting three days, was seen in animals receiving ACTH or dexamethasone plus ACTH. Testosterone excretion was stimulated by ACTH and dexamethasone plus ACTH; it was not influenced by any other treatment. The present study shows that analysis of circulating steroid levels is the only reliable approach to assess the secretory activity of Mongolian gerbil adrenals or testes. In some experimental conditions (e.g. after stressor application or ACTH treatment) cortisol excretion may be used as an index of adrenal secretory function. In contrast, the striking differences between cortisol values present in plasma and urine of peptide-or dexamethasone-treated gerbils indicate that urinary cortisol does not reflect short-term changes of adrenal function. Similarly, the striking differences of testosterone values in plasma and urine indicate that urinary testosterone monitoring cannot be used to determine the secretory activity of gerbil testes.

Investigation on Functional Reserves of the Testosterone-Synthesizing System in the Blood of 12-Month-Old Heifers in Different Breeds

“…All rights reserved) the plasma of females (Giltay et al, 1997). In addition, it takes part in the regulation of many physiological processes through specific receptors, which number can either increase or decrease (Bloom et al, 1992;Fenske, 1996). Through androgen receptors, testosterone inhibits the implementation of the gonadotropin releasing factor gene in the hypothalamus (Cardone et al, 1998), stimulates the implementation of hereditary information of androgen receptors in cells of growing follicles (Franks and Hardy, 2018).…”

“…An interesting fact is that with stress, the concentration of testosterone in the plasma rises. Moreover, the synthesis of testosterone is stimulated by ACTH (Fenske, 1996).…”