The increase in plasma progesterone levels in the pregnant guinea-pig and its possible significance.
D000818:Animals; D002369:Castration; D005260:Female; D006168:Guinea Pigs; D008297:Male; D010053:Ovary / Q000502:physiology; D011247:Pregnancy; D011270:Pregnancy, Animal; D011374:Progesterone / Q000096:biosynthesis / Q000097:blood*
D011374:Progesterone