THE EFFECT OF TESTOSTERONE AND DOI (1-(2,5-DIMETHOXY-4-IODOPHENYL)-2-AMINOPROPANE) ON MALE SEXUAL-BEHAVIOR OF RATS

The effects of a 5-HT2 receptor agonist, DOI (1-(2,5-dimethoxy-4-iodop henyl)-2-aminopropane; 0.5 mg/kg), on the behavior of male rats at dif ferent ages when given alone or with different levels of testosterone, in the presence of sexually receptive and non-receptive females are p resented. DOI increased mounting and/or mount plus thrusting behavior in adult males with receptive females. In pre-pubertal males, DOI incr eased the frequency of pursuit and genital sniffing in the presence of receptive females, but not of non-receptive ones, when no mounts or t hrustings were recorded. In castrated rats treated with testosterone a nd tested with receptive females, DOI increased the frequency of thrus ting behavior, but in castrated rats without testosterone treatment, D OI produced no change. DOI did not induce mounting in pre-pubertal or castrated rats without testosterone substitution therapy. These result s suggest that DOI influences male sexual behavior through a neural sy stem that is modulated by testosterone.