Inhibition of testosterone synthesis by ethanol: role of luteinizing hormone
Widenius, T.V.; Eriksson, C.J.; Ylikahri, R.H.; Härkönen, M.
Alcohol 6(3): 241-244
ISSN/ISBN: 0741-8329 PMID: 2736083 DOI: 10.1016/0741-8329(89)90025-6
The effects of acute ethanol intake (1.5 g/kg) on plasma testosterone and luteinizing hormne (LH) concentrations were examined in male Long-Evans rats. Ethanol decreased the serum LH concentrations by 21% and 42% 30 and 60 minutes after ethanol administration respectively. The testosterone concentrations decreased later (30 min: +8%; 60 mn: -30%). The LH concentrations were highly correlated with subsequent (60 min later) testosterone concentrations (LH30 min: r = .688, p < 0.001, n = 25; LH60 min:r = .678, p < 0.001), but less so with concurrent testosterone concentrations (30 min: r = .187, N.S.; 60 min; r = .552, p < 0.004). To further test the influence of LH, naloxone (11 mg/kg) was administered, which elevated the LH levels within 30 min by 103% in controls. Naloxone also increased serum LH concentration by 34% in ethanol-treated rats at 30 min, but these animals nevertheless had lower (p < 0.01) testosterone levels at 60 min than did control animals without naloxone and ethanol treatment. It is concluded that although ethanol-induced changes in serum LH levels may play a role in the decrease of serum testosterone concentrations in rats, there are also other mechanisms by which ethanol may produce these effects.