During luteinization, there is hypertrophy and hyperplasia of theca cells, which give rise to small luteal cells. Small luteal cells possess functional LH receptors that are involved in regulation of progesterone secretion, but LH receptors in large luteal cells of granulosa origin are not involved in regulation of secretion of progesterone; these large cells secrete large amounts of progesterone in the absence of LH stimulation. It is possible, therefore, that in the absence of release of LH pulses during the late stages of ovarian follicular maturation and early luteal development, small luteal cells do not receive the proper stimulation to secrete progesterone and without LH stimulation are not capable of developing into large luteal cells that secrete greater amounts of progesterone.
Secretion of progesterone from the CL of females in which episodic release of LH was inhibited was also suppressed compared with that of females from the control group. Interestingly, there is decreased frequency of LH pulses during the follicular phase of the menstrual cycle of women with a subfunctional CL.