The extrinsic blood vessels of the ovary of the sheep

Expression of aquaporin 1 in the pig peri-ovarian vascular complex during the estrous cycle and early pregnancy

Aquaporin 1 (AQP1) is a water channel protein expressed in endothelial and epithelial cells of many tissues, including the vasculature, where it serves to increase water permeability of the cell membrane. The aim of this study was to investigate the expression and distribution of AQP1 in porcine peri-ovarian vascular complex (PVC) during the estrous cycle and early pregnancy. Immunohistochemistry and semi-quantitative immunoblotting techniques were used. We have demonstrated the presence of AQP1 protein in the endothelial cells of the lymphatic and vascular endothelium of the PVC during the pig estrous cycle and early pregnancy. The expression of AQP1 protein in the PVC did not change significantly between Days 10-12 and 14-16, but increased on Days 2-4 and 18-20 when compared with Days 10-12 and 14-16 of the estrous cycle. In pregnant gilts, the expression of AQP1 did not differ significantly during the onset and the end of the implantation process and also when compared to the mid- and late-luteal phases of the estrous cycle. In conclusion, AQP1 is expressed in the endothelial cells of PVC and may modulate hormonal regulation of reproductive organs.

Short-term studies of ovarian metabolism in the ewe

The ovarian uptake of metabolites in anaesthetised ewes was determined. In both studies, catheters were inserted into the ovarian vein and femoral artery, and Transonic flow transducers were placed around the ovarian arterio-venous plexus. Arterio-venous differences in glucose, lactate, free fatty acids (FFA), 3-hydroxybutyrate (3-OHB), acetate, cholesterol and progesterone and oestradiol-17 beta levels were determined every 10 min over a 3.5 h period. In study one, glucose uptake was significant in three sheep, and one sheep only had a significant uptake of FFA. Ovarian 3-OHB uptake was significant in two sheep. significant uptake of acetate or cholesterol was identified in one sheep. Progesterone secretion was significant in three sheep and two sheep had significant progesterone uptake. In study 2, glucose uptake was significant in four sheep and lactate release was significant in the same sheep. There was uptake of FFA and 3-OHB, cholesterol, and acetate in each of three different sheep. Oestradiol-17 beta output was significant for sheep in oestrus and prooestrus. While the effects of gonadotrophin-releasing hormone (GnRH) treatment were confounded by time spent under anaesthesia, exogenous GnRH appeared to have no significant effect on the uptake of most metabolites and steroid hormone outputs. The metabolic requirements for energy and precursors for progesterone was small. Glucose was the major source of energy for the ovary and appears to be metabolised through anaerobic pathways, as indicated by significant lactate output.

Ovarian, oviductal, and adrenal vascular connections in female lizards (genus Anolis)

The urogenital blood vessels of Anolis equestris and A. carolinensis were studied using dissection, injection of silicone rubber, and histology. A new blood-vascular connection between small veins in the pampiniform plexus at the base of the ovary and an ostial extension of the secondary oviductal vein is described. Chemical messengers could thus be carried in the blood from the ovarian venous drainage to the oviduct. Furthermore, close apposition of the secondary oviductal vein and artery provides an anatomical basis for countercurrent exchange of these messengers. A circular venous arcade, involving the supracardinal vein and branches of the oviductal veins, also is described; this arcade could serve to deliver adrenal hormones to each oviduct.

Countercurrent exchange of progesterone and antipyrine between human utero-ovarian vessels, and of antipyrine between the femoral vessels in the cat

The utero-ovarian vein and ovarian artery in surgical specimens were cannulated and perfused in a countercurrent manner with isotonic, buffered solutions, fortified on the venous side with progesterone or radiolabelled methylantipyrine. Both substances were gradually transferred from the vein into the artery in the majority of the experiments while albumin was not exchanged. The results point to the existence of a countercurrent exchange mechanism in the human ovarian pedicle. Hardly detectable amounts of methylantipyrine were transferred from femoral vein to artery in the cat.