RESUMEN
Menstrual patterns and progesterone levels were monitored for 5 years from a cohort of 28 female vervet monkeys that were individually caged indoors. Three distinct cycle types (short, normal, and prolonged) were defined according to cycle length. Mean length of the normal cycle (32.5 days) and menses duration (4.8 days) are in agreement with previous reports. Prolonged cycles (> 50 days) contributed 20% of the total, with a decreased incidence during the natural peak breeding period. Weekly progesterone measurements indicated that many prolonged cycles were associated with an extended luteal phase, while others were probably due to lack of ovulation. From these data it would appear that the vervet monkey, although not strongly seasonal, does favor a particular time of year for breeding in a colony housed indoors.
RESUMEN
Ovarian and placental steroid secretion was examined at intervals during early and mid-pregnancy in the olive baboon, Papio anubis. Progesterone, androstenedione, testosterone, estrone, and estradiol-17ß were measured after celite chromatography in samples from peripheral circulation and from utero-ovarian veins draining ovaries with and without corpora lutea at the following stages of pregnancy: days 8-9 (unconfirmed pregnant), 10-19, 34-40, 60-66, and 104-106 after ovulation. The pattern of hormone levels in peripheral and utero-ovarian vein samples indicated the following: 1) The corpus luteum was the principal source of progesterone until at least day 19. Placental secretion was well advanced by days 34-40 and provided the major contribution to circulating progesterone levels by day 60.2) There was a significant elevation in peripheral concentrations of androstenedione and testosterone on days 10-19 and 34-40 of pregnancy; androgen levels in peripheral and utero-ovarian vein samples declined to baseline values by day 60. 3) Estrogens were secreted by the corpus luteum on days 10-19 but not on days 34-40. Placental secretion of estradiol-17ß increased markedly after days 60-66, whereas little, if any, placental secretion of estrone was apparent at this time. These results provide circumstantial evidence that progesterone secretion by the corpus luteum of early pregnancy extends beyond the time when estrogen secretion has declined and that the timing of the luteo-placental shift in the baboon is intermediate between that in rhesus monkeys and that in marmosets and humans. Increased secretion of androgens during the first 6 weeks of gestation may be useful in early pregnancy diagnosis in the baboon, although the physiological significance of this event is not clear.