Effect of the neonatal steroid hormone treatment of rats on adult hormone levels and the reactivity of seminal vesicles to parasympathomimetic drugs.
1. Seminal vesicle reactivity to cholinergic agents, plasma testosterone, luteinizing hormone (LH) and follicle stimulating hormone (FSH) concentrations and seminal vesicle testosterone concentrations were determined in adult male rats treated during the first 6 h of life with 1.0 ml peanut oil (oil-treated), 1.0 mg testosterone propionate (TP-treated) or 1.2 mg 19-nor-testosterone homofarnesate (19-NT-treated). 2. At 90-100 days of age, the neonatally treated animals presented atrophied accessory genital organs and increased (TP-treated, N = 10) or unchanged (19-NT-treated, N = 11) pD2 values for acetylcholine (vehicle: 5.18 +/- 0.06, N = 10; TP-treated: 5.26 +/- 0.06, N = 10; 19-NT-treated: 5.14 +/- 0.09, N = 11), and acetyl-beta-methylcholine (vehicle: 5.19 +/- 0.07; TP-treated: 5.43 +/- 0.06; 19-NT-treated: 5.25 +/- 0.07). The relative intrinsic activity, alpha, of acetyl-beta-methylcholine increased after both hormonal treatments (vehicle: 0.85 +/- 0.03; TP-treated: 0.95 +/- 0.02; 19-NT-treated: 0.92 +/- 0.03). 3. No variation in mean adult plasma testosterone concentration was observed after neonatal treatment with either TP or 19-NT (vehicle: 752.93 +/- 273.66, N = 8; TP-treated: 459.05 +/- 88.32, N = 8; 19-NT-treated: 836.86 +/- 113.08, N = 7). However, testosterone content of seminal vesicles of adult rats was decreased in the animals treated with TP (N = 5) and 19-NT (N = 6) compared to controls. 4. These results indicate a specific effect of neonatal hormone treatment on androgen metabolism which is demonstrable in the adult.