Katz L S
Vet Clin North Am Food Anim Pract. 1987 Jul;3(2):393-404. doi: 10.1016/s0749-0720(15)31160-9.
Estradiol, either directly from the ovary of females or as a metabolite of testosterone from the testes of males, seems to be the necessary and probably sufficient endocrine signal for sexual differentiation and adult sexual expression. Progesterone, in females, may play an important priming or facilitative role prior to estrus, especially following pregnancy, when blood estrogen levels are high for a prolonged period. At high doses, progesterone clearly inhibits the expression of sexual behavior.
雌二醇，无论是直接来自雌性的卵巢，还是作为雄性睾丸中睾酮的代谢产物，似乎都是性分化和成年期性行为表达所必需的内分泌信号，而且可能是充分的内分泌信号。在雌性中，孕酮在发情期之前可能发挥重要的启动或促进作用，尤其是在怀孕后，此时血液中的雌激素水平会在较长时间内保持较高。高剂量时，孕酮会明显抑制性行为的表达。
