PT  - JOURNAL ARTICLE
AU  - M L Adams
AU  - E R Meyer
AU  - B N Sewing
AU  - T J Cicero
TI  - Effects of nitric oxide-related agents on rat testicular function.
DP  - 1994 Apr 01
TA  - Journal of Pharmacology and Experimental Therapeutics
PG  - 230--237
VI  - 269
IP  - 1
4099  - http://jpet.aspetjournals.org/content/269/1/230.short
4100  - http://jpet.aspetjournals.org/content/269/1/230.full
SO  - J Pharmacol Exp Ther1994 Apr 01; 269
AB  - The effects of nitric oxide (NO)-related agents on testicular function were examined in male rats with measurements of serum luteinizing hormone, serum testosterone, testicular interstitial fluid (TIF) testosterone, and TIF volumes. Serum and TIF testosterone levels and luteinizing hormone secretion were significantly decreased by the NO donor, isosorbide dinitrate (ISDN), and the NO synthase (NOS) substrate, L-arginine methyl ester, a source for the endogenous production of NO. The effects of ISDN on TIF volumes were inconsistent, but L-arginine methyl ester decreased TIF formation in a dose-dependent manner. In addition, ISDN dose dependently suppressed testosterone secretion stimulated by human chorionic gonadotropin treatment, suggesting that the effects on testosterone secretion were independent of changes in secretion of the endogenous gonadotropin luteinizing hormone. ISDN, L-arginine methyl ester, and the endogenous NOS substrate L-arginine completely blocked testosterone secretion stimulated by the NOS inhibitor NG-nitro-L-arginine methyl ester (NAME), whereas the relatively inactive NOS substrate, D-arginine, only partially blocked NAME-stimulated testosterone secretion. Hydralazine and nicardipine, two vasodilators that do not exhibit prominent NO-related effects, also blocked basal testosterone secretion and testosterone secretion stimulated by the vasoconstrictor NAME.(ABSTRACT TRUNCATED AT 250 WORDS)