Arterial levels of 13,14-dihydro-15-keto-PGE2 (PGE2-M), a stable metabolite of prostaglandin E2 (PGE2) were compared between unanesthetized pregnant (n=12) and nonpregnant (n=8) rabbits with the aim of elucidating the role of PGE2 in the development of physiological hypotension associated with pregnancy. On the 20th and 22nd days of 30 day gestation period of mean arterial concentration of PGE2-M were about 10-times higher (p<0.05) and largely variable as compared that of nonpregnant rabbits. Mean arterial pressure was not lower on either the 20th (60±44 mmHg, mean±SD) or the 22nd (70±3 mmHg) days of gestation (dg) than in nonpregnant rebbits 69±4 and 73±6 mmHg, respectively). On the 23rd dg hypotensions was invariably present (61±5 mmHg vs 72±4 in nonpregnants, p < 0.001), but arterial levels of PGE2-M (31.0±31.6 ng/ml) did not overcome those measured on earlier, normotensive days of gestation. Hypotension was also evident in a subgroup of pregnant rabbits (n=4) with low PGE2-M concentrations in the nonpregnant range (3.2±5 ng/ml vs 1.9±1.2 in nonpregnant rabbits, ns). Since the arteial level of PGE2-M proved to corelated (p < 0.001) with both the uteroplacental venous and renal venous PGE2 concentrations, we suggest that a key role of uteroplacental and renal PGE2 played in the development of gestational hypotension is not probable in rabbits.
ASJC Scopus subject areas