Acute alcohol exposure markedly influences male fertility and fetal outcome in the male rat.

Although it is recognized that drugs ingested by pregnant females produce marked cognitive and physiological deficits in their offspring, the possibility that paternal exposure to drugs prior to mating may have adverse effects on fertility and fetal outcome has not received much attention. The purpose of the present studies was to examine whether a single, acute exposure to alcohol influences the subsequent ability of adult male rats to mate and produce healthy and viable litters. Our results showed that a relatively large dose of alcohol 24 hours prior to breeding had little effect on the mating behavior of male rats, but there were markedly fewer pregnancies in females mated with alcohol-exposed male rats than in controls. Of equal importance, we found that, even when conception occurred and live births were produced, there were striking differences in fetal outcome. Alcohol-treated males sired many fewer pups than control males and there was a markedly enhanced mortality rate in their offspring. Collectively, these data suggest that acute paternal alcohol administration 24 hours prior to breeding does not affect mating behavior, but results in a greatly diminished fertility rate and fewer and less viable offspring. These studies suggest that paternal alcohol use may be as important as maternal alcohol abuse as a negative variable in pregnancy and fetal outcome.

Acute paternal alcohol exposure impairs fertility and fetal outcome.

An acute injection of an intoxicating dose of alcohol to male rats 24 hours prior to breeding with drug-naive females produced no discernible effect on copulatory activity, as reflected in vaginal plugs, but resulted in markedly (> 50%) reduced pregnancy rates. Fetal outcome was also markedly affected in offspring sired by alcohol-treated males: litter sizes were appreciably smaller (30%) and fetal mortality was more than 2 times higher than in controls. These results suggest that paternal alcohol use, like maternal alcohol abuse, may adversely affect fertility and fetal outcome.

Effects of nitric oxide-related agents on alcohol narcosis.

To examine whether nitric oxide (NO) affects alcohol (ethanol) narcosis, adult male rats were pretreated with a NO synthase (NOS) inhibitor, NG-nitro-l-arginine methyl ester (NAME); a NOS substrate, l-arginine methyl ester (AME); or a NO donor, isosorbide dinitrate (ISDN); then treated with anesthetic doses (3-5 g/kg, ip) of alcohol. Pretreatment with NAME (30-100 mg/kg, sc) 40 min before alcohol treatment delayed the onset of alcohol-induced loss of the righting reflex (LORR) and increased the duration of the LORR. NAME (100 mg/kg) pretreatment combined with high doses of alcohol (4-5 g/kg) exerted significant lethal effects, even though treatment with either agent alone or NAME combined with lower doses of alcohol (3-3.5 g/kg) was not lethal. Simultaneous treatment with the NOS substrate AME (100 mg/kg, subcutaneous) blocked the effects of NAME on LORR duration times, but did not alter LORR onset times. The NO donor ISDN (30 mg/kg) given by oral gavage 2 hr before alcohol decreased LORR duration times without affecting the onset of LORR. In addition, ISDN dose-dependently inhibited NAME-induced LORR duration increases during alcohol narcosis without significantly altering LORR onset times. Neither ISDN nor NAME significantly altered blood alcohol concentrations. These results suggest that NOS inhibition and subsequent decreases in NO production enhance alcohol-induced narcosis and that increases in NO concentrations inhibit alcohol narcosis, supporting the hypothesis that inhibition of arginine-NOS-NO systems mediates part of the sedative-hypnotic effect of alcohol.

Effects of nitric oxide-related agents on rat testicular function.

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)

Nitric oxide-related agents alter alcohol withdrawal in male rats.

Evidence has been reported supporting the hypothesis that nitric oxide (NO) partially mediates the expression of morphine dependence. To examine whether NO-related agents also affect the expression of alcohol dependence, adult male rats were treated chronically with alcohol. Upon withdrawal of alcohol administration, abstinence signs were observed after treatment with a NO synthase (NOS) inhibitor, NG-nitro-L-arginine methyl ester (NAME), or a NO donor, isosorbide dinitrate (ISDN). Withdrawal severity was based primarily on the presence and intensity of tremors, rigidity, hyperactivity, and spontaneous and audiogenic convulsions. The NOS inhibitor, NAME (10-100 mg/kg), injected during alcohol withdrawal significantly inhibited withdrawal severity decreasing the intensity of signs of hyperactivity, tremors, and rigidity, but not affecting the occurrence of convulsions. The NO donor, ISDN (30 mg/kg), administered during alcohol withdrawal significantly increased the severity of most withdrawal signs. These results suggest that NO mediates some aspects of the expression of alcohol dependence.