Placental protein 13 dilation of pregnant rat uterine vein is endothelium dependent and involves nitric oxide/calcium activated potassium channels signals.

INTRODUCTION: Accumulating evidence demonstrates the importance of the galectin protein Placental Protein 13 (PP13) in predicting Preeclampsia (PE), a gestational disorder that has no cure and is associated with a compromised uterine vascular adaptation to pregnancy. Uterine vasculature undergoes significant remodeling (growth in length and in circumference) during normal pregnancy to accommodate the increased blood volume to the feto-placental unit. The aim of this study was to demonstrate the role of PP13 on the uterine veins (UVs). METHODS: PP13 was tested on UVs isolated from rat by using a pressurized myograph. The PP13 investigation was carried out in the presence of: a) nitric oxide synthases inhibitors (l-NAME + L-NNA, 2 x 10-4 M); b) small conductance Ca2+-activated K+ channels (SKca) inhibitor (Apamin, 10-7 M); c) intermediate conductance Ca2+-activated K+ channels (IKca) inhibitor (TRAM-34, 10-5 M); d) big conductance Ca2+-activated K+ channels (BKca) inhibitor (Paxilline, 10-5 M) and in the absence of endothelium. RESULTS: Our results showed that in late pregnancy, PP13 induced a significant dilation of UVs that is endothelium dependent. Further, PP13-dilation is mediated by the SKca - NO - BKca pathway. DISCUSSION: For the first time, this study provides evidence that in pregnancy, the UVs are dilated by PP13 and suggests SKCa as a potential target for treatments aimed at restoring pregnancy complication associated with deficiency in uterine adaptation.

Serum leptin concentrations, leptin mRNA expression, and food intake during the estrous cycle in rats / 한국실험동물학회지

The aim of this study was to investigate food intake, serum leptin levels, and leptin mRNA expression during the sexual cycle in rats. Female Wistar-Imamichi rats aged 8-10 weeks were used in this experiment. Food intake was measured during the light and dark phases (light on at 07:00 and off at 19:00) of the 4-day estrous cycle in female rats. Serum leptin levels were measured by ELISA, and leptin mRNA expression levels were analyzed using real-time PCR on diestrous- and proestrous-stage rats. Our results revealed that during the sexual cycle, food intake was significantly higher in the dark phase compared with the light phase. Food intake in proestrous females was significantly lower in the light and dark phases compared with the other groups. Serum leptin concentrations were significantly higher in both phases in proestrous rats compared with diestrous rats. There was a significant increase in leptin mRNA expression in adipose tissue during the proestrous period compared with the diestrous period. These findings suggest that increased leptin mRNA expression and serum leptin levels, which are induced by estrogen during the proestrous stage, may play a role in regulating appetitive behavior.