Pulsatile progesterone secretion: Its relevance to clinical evaluation of corpus luteum function

Pulsatile progesterone (P) secretory patterns were characterized in rhesus macaques (n = 13) during the midluteal phase (cycle days 18 to 20) of the normal ovarian/menstrual cycle. Sixty high-amplitude (> 1 ng/ml) P pulses were observed during a total of 169 hours of sampling. Typically, P pulses had an ultradian periodicity of 2 hours and were independent of detectable luteinizing hormone (LH) and prolactin (PRL) pulses in 70% of instances. LH pulses were associated with a concomitant P and PRL pulse in 100% to 80% of occasions, respectively. Pulsatile P release was augmented by exogenous cynomolgus monkey LH and suppressed by administration of a gonadotropin-releasing hormone antagonist. Two individuals with apparently normal ovulation and once daily plasma P concentrations within the normal range demonstrated a nonpulsatile P profile. These findings encourage clinical investigations to characterize pulsatile P secretion in normal women and patients in whom corpus luteum dysfunction is suspected.