The proposal will define the mechanism by which restraint stress inhibits the testicular response to gonadotropin in male rats and determine the involvement of peptides produced in the testes (ACTH, beta-endorphin, alpha-MSH and arginine vasopressin) in mediating this process. Experiment 1 will examine the effect of restraint stress on testicular steroidogenesis in vitro. The effect of restraint on LH bioactivity and LH receptors on interstitial cells will be determined. Steroid production from cultured interstitial cells will be assessed to identify specific steps in the steroidogenic pathway that are altered by stress. The effect of restraint stress on the activity of key steroidogenic enzymes will be determined. HDL and LDL receptor binding will be compared between isolated interstitial cells from stressed and unstressed rats. Experiment 2 will examine the effect of stress-sensitive- pituitary peptides and glucocorticoids on the same parameters in cultured interstitial cells from unstressed rats. The influence of stress on the volume of testicular interstitial fluid (TIF) and the level of opiomelanocortin peptides and arginine vasopressin in TIF will be determined in Experiment 3. Experiment 4 will examine the effect of incubating TIF from stressed and unstressed rats on steroid production by cultured control intersititial cells. Specific antagonists of peptides found in TIF will be incubatied with TIF from stressed and unstressed rats and the effect on steroid production by control interstitial cells determined in Experiment 5. In Experiment 6, the effect of selective destruction of Leydig cells on the ability of TIF from stressed rats to alter steroid production by control interstitial cells in vitro will be assessed to determine the source of the active regulatory factors in TIF. These experiments will define the mechanism of stress-induced testicular hyposensitivity to gonadotropin and the role of testicular peptides in this regulatory process.

Agency
National Institute of Health (NIH)
Institute
Eunice Kennedy Shriver National Institute of Child Health & Human Development (NICHD)
Type
Research Project (R01)
Project #
1R01HD023295-01
Application #
3323390
Study Section
Reproductive Endocrinology Study Section (REN)
Project Start
1987-08-01
Project End
1990-07-31
Budget Start
1987-08-01
Budget End
1988-07-31
Support Year
1
Fiscal Year
1987
Total Cost
Indirect Cost
Name
Morehouse School of Medicine
Department
Type
Schools of Medicine
DUNS #
City
Atlanta
State
GA
Country
United States
Zip Code
30310
Akinbami, M A; Philip, G H; Sridaran, R et al. (1999) Expression of mRNA and proteins for testicular steroidogenic enzymes and brain and pituitary mRNA for glutamate receptors in rats exposed to immobilization stress. J Steroid Biochem Mol Biol 70:143-9
Akibami, M A; Mann, D R (1996) Mechanism of stress-induced attenuation of the testicular response to gonadotropin: possible involvement of testicular opioids, a pertussis toxin-sensitive G-protein, and phosphodiesterase. J Androl 17:10-6
Srivastava, R K; Akinbami, M A; Mann, D R (1995) Acute immobilization stress alters LH and ACTH release in response to administration of N-methyl-D,L-aspartic acid in peripubertal and adult male rats. Life Sci 56:1535-43
Orr, T E; Taylor, M F; Bhattacharyya, A K et al. (1994) Acute immobilization stress disrupts testicular steroidogenesis in adult male rats by inhibiting the activities of 17 alpha-hydroxylase and 17,20-lyase without affecting the binding of LH/hCG receptors. J Androl 15:302-8
Srivastava, R K; Taylor, M F; Mann, D R (1993) Effect of immobilization stress on plasma luteinizing hormone, testosterone, and corticosterone concentrations and on 3 beta-hydroxysteroid dehydrogenase activity in the testes of adult rats. Proc Soc Exp Biol Med 204:231-5
Orr, T E; Mann, D R (1992) Role of glucocorticoids in the stress-induced suppression of testicular steroidogenesis in adult male rats. Horm Behav 26:350-63
Orr, T E; Mann, D R (1990) Effects of restraint stress on plasma LH and testosterone concentrations, Leydig cell LH/hCG receptors, and in vitro testicular steroidogenesis in adult rats. Horm Behav 24:324-41
Mann, D R; Gould, K G; Collins, D C (1990) A potential primate model for bone loss resulting from medical oophorectomy or menopause. J Clin Endocrinol Metab 71:105-10
Mann, D R; Orr, T E (1990) Effect of restraint stress on gonadal proopiomelanocortin peptides and the pituitary-testicular axis in rats. Life Sci 46:1601-9
Mann, D R; Gould, K G; Collins, D C et al. (1989) Blockade of neonatal activation of the pituitary-testicular axis: effect on peripubertal luteinizing hormone and testosterone secretion and on testicular development in male monkeys. J Clin Endocrinol Metab 68:600-7

Showing the most recent 10 out of 11 publications