Levels of Estrogens, Progestogens and Luteinizing Hormone During the Menstrual Cycle of the Baboon

Abstract

Measurements of plasma LH, urinary LH, urinary estrogens, plasma progesterone and plasma “progestins” were made during several baboon menstrual cycles. Single midcycle LH peaks were observed in all cycles in both plasma and urine. Plasma progesterone and “progestin” patterns were similar during the cycle except that a midcycle peak in “progestins” consistently occurred coincident with LH and estrogen peaks. Urinary estrogens showed an increase during the follicular phase of the cycle with a sharp peak occurring at midcycle. No significant estrogen peaks were observed during the luteal phase. Levels of progestogens, estrogens and LH were quantitatively about one third those reported during the human menstrual cycle. The significance of these species differences is discussed.(Endocrinology87: 658, 1970)