Utero-Ovarian Relationships in the Guinea Pig1

Abstract

REVIEW OF LITERATURE. 2 Reproductive Biology of the Guinea Pig 2 Hysterectomy-MATERIALS AND METHODS Hysterectomy Chemical Destruction of the Endometrium Uterine Transplantation Unilateral Ovariectomy and Partial Hysterectomy-Miscellaneous Observations on the Effects of Reproductive Hormones RESULTS AND DISCUSSION Hysterectomy Chemical Destruction of the Endometrium 43 Uterine Transplantation 45 Unilateral Ovariectomy and Partial Hysterectomy-48 Miscellaneous Observations on the Effects of Reproductive Hormones SUMMARY LITERATURE CITED 61 ACKNOWLEDGMENTS 71 REVIEW OF LITERATURE Reproductive Biology of the Guinea Pig The guinea pig under laboratory conditions is polyestrous the entire year. Estrus lasts less than half a day and the estrous cycle is about 16.5 days. Ovulation is spontaneous and the corpora lutea of the estrous cycle are functional. Gestation is about 67 to 68 days, with a litter size of about 3 to 4 (Asdell, 1946). Estrous cycle and gestation Ishii (1920) reported the age of puberty as 55 to 70 days. Young ejt al. (1939) stated the average age of puberty is 67.8 days with a range of 33 to 134 days. The vaginal opening is closed by a membrane except for a period of about 4 days at each estrus. Kelly and Papanicolaou (1927) described this structure as a solid epithelial vulvar cord extending 1 to 2 mm.; in depth. The opening of the membrane occurs at the inflamma tory stage of the sexual cycle. Opening is caused by the cornification and subsequent desquamation of the central part of the vulvar cord. Young e_t al. (1933) and Young e£ al. (1935) reported the average length of the estrous period as about 8 hours with a range of 1 to 18 hours. The former authors report ovulation occurs within an hour after the termination of estrus. Young et al. (1935) observed about 64 percent of all heats begin be

EFFECT OF p‐BROMOPHENACYL BROMIDE, AN INHIBITOR OF PHOSPHOLIPASE A2, ON ARACHIDONIC ACID RELEASE AND PROSTAGLANDIN SYNTHESIS BY THE GUINEA‐PIG UTERUS in vitro

“…Both may occur in the endometrium or in the myometrium, or there may even be an interaction between the two sites. Prostaglandin synthesis is likely to take place in the endometrium since its chemical destruction prolongs the oestrous cycle in the guinea-pig (Butcher, Chu & Melampey, 1962). So far, it has proved extremely difficult to separate the guinea-pig uterus into the endometrium and myometrium in vitro, so as to resolve this point.…”

Relation of Local Circulation between Ovaries and Uterus to Lifespan of Corpora Lutea in Rats

“…The part of the uterus which appears to influence the lifespan of the corpora lutea is the endometrium (3)(4)(5). Partial hysterectomy prolongs maintenance of corpora lutea in direct proportion to the amount of uterine tissue removed (4)(5)(6). Uterine transplants in hysterectomized rats were reported to shorten the duration of pseudopregnancy…”

Luteolysis as Affected by Uterine Transplantation in the Syrian Hamster

“…In the hamster and rat, this relationship is apparently not important. Both success (25) and failure (1) have been reported in guinea pig studies in which uterine transplantation was tested as a means for shortening prolonged corpora luteal function. As yet, this matter is unresolved.…”