-
Views
-
Cite
Cite
BRUCE B. VIRGO, GAIL D. BELLWARD, Serum Progesterone Levels in the Pregnant and Postpartum Laboratory Mouse, Endocrinology, Volume 95, Issue 5, 1 November 1974, Pages 1486–1490, https://doi.org/10.1210/endo-95-5-1486
Close - Share Icon Share
The serum progesterone concentration ([P])2 was measured in Swiss-Vancouver mice by a competitive protein-binding assay. Virgin females, 9–11 weeks old, were kept on a 14-hr light regime (on between 0600–2000) and bred between 2000– 0800 hr. Females were exsanguinated from the intra-orbital sinus between 0800–0900 hr on 17 of the 20 gestation days or within 5 hr postpartum. The mean [P] increased gradually from 4.9 ng⁄ml on Day 0 (plug day) to 14.7 ng⁄ml on Day 2. From Day 2 to Day 3 the [P] significantly increased (p < 0.05) to 45.5 ng⁄ml and this level was then maintained until Day 8. Between Day 8 and Day 9 the [P] decreased significantly to 19.0 ng⁄ml. The [P] on Day 10, 35.5 ng⁄ml, was significantly greater than that on Day 9 and it increased steadily until Day 16 when the highest levels, averaging 81.9 ng⁄ml, were found. The [P] on Day 18, 27.6 ng⁄ml, was significantly less than that on day 16. On Day 19, 4 hr before parturition, the [P], 7.3 ng⁄ml, was significantly less than that on Day 18; after delivery, the [P] in 1 dam was 1.1 ng⁄ml while in 2 others it was <0.8 ng⁄ml. We conclude that: 1) P secretion begins shortly after copulation; 2) [P] changes over Days 2–9 in relation to the roles of P in inducing and maintaining decidualization; and 3) P withdrawal is required to permit parturition. (Endocrinology95: 1486, 1974)
