Failure of dopamine to promote spermiation in toads

Abstract

Schneider and McCann ( Endocrinology 85, 121, 1969) demonstrated that dopamine elicits secretion of LH in rats. In order to study whether a similar effect could be demonstrated in toads, dopamine was applied directly onto the median eminence, injected intracardially, or the tissue content of this catecholamine was increased pharmacologically. Spermiation was used as a parameter of LH secretion. In none of the animals spermiation was observed; these negative results are discussed in the light of current knowledge of the hypothalamic-hypophyseal relationships.