Opposite effects of 5-methoxy-N,N-di-methyl-tryptamine and 5-hydroxytryptophan on male rat sexual behavior.
Pharmacology, biochemistry, and behavior January 1, 1991 DOI: 10.1016/0091-3057(91)90611-5
Summary
Administering 5-methoxy-N,N-di-methyl-tryptamine (5-MeODMT) significantly enhanced male rat sexual behavior, with a notable decrease in ejaculation latency and intromissions before ejaculation. At a dose of 1 mg/kg, its effects were reversed by pindolol (4 mg/kg), while other compounds like pirenperone and metergoline showed no antagonistic effect. Additionally, 5-HTP increased mounts and intromissions in animals pre-treated with benserazide. Pindolol alone mirrored 5-HTP's effects, indicating that activating specific brain receptors can either promote or inhibit sexual behavior in male rats.
Abstract
The administration of 5-methoxy-N,N-di-methyl-tryptamine (5-MeODMT), O-2.0 mg.kg-1 SC -15 min, produced a dose-dependent facilitation of the male rat sexual behavior, as evidenced by a decrease in the number of intromissions to ejaculation and in the ejaculation latency. The effects produced by 5-MeODMT (1 mg.kg-1) were antagonized by pindolol (4 mg.kg-1 SC -30 min), but not pirenperone (0.25 mg.kg-1 SC -30 min) or metergoline (1 mg.kg-1 SC -30 min), administration. As expected, 5-HTP (25 mg.kg-1 SC -60 min) produced an increased number of mounts and intromissions to ejaculation and an increase in the ejaculation latency in benserazide (25 mg.kg-1 SC -90 min) pretreated animals. Pindolol (4 mg.kg-1) by itself produced the same effects as seen after 5-HTP administration, and the combination of these compounds produced additive effects. Betaxolol (8 mg.kg-1 SC -30 min) had no effects of its own and did not interact with 5-HTP. The results suggest that stimulation of brain 5-HT1 or 5-HT2 receptors produces facilitation and inhibition, respectively, of the male rat sexual behavior.