Relaxin contributes to the regulation of arterial pressure in adult female mice

Relaxin is increasingly being recognized as a potent vasodilatory and anti-fibrotic hormone. Given that relaxin is present in the circulation during luteal phase of the menstrual cycle and during pregnancy, when arterial pressure is lowest in women, relaxin may contribute to the relative cardiovascular protection observed in premenopausal women as compared to age-matched men and post-menopausal women. In the present study, we investigated the contribution of relaxin to the normal regulation of arterial pressure in adult female and male mice and during pregnancy. Mean arterial pressure (MAP) was measured via radiotelemetry in 14-week-old male and female wild-type (WT; C67BL/6xSv129) and relaxin knockout (KO) mice. Thereafter, female mice were time-mated with a (non-telemetered) male of the same genotype and MAP was measured throughout gestation. Basal MAP was ~10 mmHg lower in WT females than males (P<0.05). Relaxin deficiency increased basal MAP in females (P<0.05 versus WT female), but not males. As expected, MAP decreased during gestation in WT mice. Conversely, in relaxin KO mice, arterial pressure increased during mid and late gestation (P<0.05 as compared to WT). Moreover, relaxin deficiency impaired gestational weight gain and reduced litter size. This is the first study to i) demonstrate that relaxin contributes to the sexual dimorphism of arterial pressure in mice and ii) document the changes in the arterial pressure profile of pregnant relaxin KO mice. Under...
Source: Clinical Science - Category: Biomedical Science Authors: Tags: PublishAheadOfPrint Source Type: research