AGONISTIC BEHAVIOR, PLASMA TESTOSTERONE, AND HYPOTHALAMIC ESTRADIOL BINDING IN MALE RABBITS

The purpose of this study was to establish a relation between agonisti c behavior, gonadal hormones, and their receptorial capacity at the ce ntral level. Male rabbits were observed in seminatural conditions and three components of their agonistic behavior were recorded: follow, at tack, and chase, The three behaviors were mutually correlated and clea rly differed among the four members of each group. Within the social g roup, one rabbit was agonistically more active than the others and his supremacy was associated with an increased level of peripheral testos terone and higher estradiol binding in the hypothalamus. On the whole, the values of the hypothalamic estradiol binding were positively corr elated with the behaviors. The results show that, in the male rabbit, agonistic activity is associated with changes in testosterone concentr ation and in the binding at the central level of its aromatized metabo lite estradiol. (C) 1997 Wiley-Liss, Inc.