Does seminal plasma affect angiogenesis in the porcine oviduct?

In the present study we examined the effect of seminal plasma (SP) on angiogenesis in the porcine oviduct. Gene expressions of vascular endothelial growth factor (VEGF) and its two receptors (Flt-1: fms-like tyrosine kinase and Flk-1/KDR: fetal liver kinase-1/kinase insert domain-containing receptor) as well as fibroblast growth factors (FGF-1 and 2) and von Willenbrand factor (VWF) were determined in the oviduct of SP-treated and control (PBS-treated) gilts. Moreover, vascular density (VD) indicated by endothelial cell area immunolocalized by VWF staining, was assessed in the oviducts. Real-time PCR revealed significantly higher expression of FGF-2 and VWF on day 1 (p<0.05) after SP administration in comparison to control animals. In contrast, Flt-1 mRNA level on day 1 was lower in SP-treated gilts compared to controls (p<0.05). In the examined oviductal sections, VD did not differ between control and SP-treated animals. However, in SP-treated animals VD was higher on day 5 than on day 1 (p<0.05) or 3 (p<0.01). SP had no significant effect on VEGF, Flk-1/KDR and FGF-1 mRNA expression. In conclusion, our results suggest that SP affects the vascular network by changing the expression of factors contributing to angiogenesis.

Ultrastructure of anterior uterus of the oviduct and the stored sperm in female soft-shelled turtle, Trionyx sinensis.

Ultrastructure of sperm storage in female soft-shelled turtle, Trionyx sinensis was examined under light and electron microscopes. Sperm storage tubules are restricted to the anterior of the uterus. These tubules developed either by folding or fusion of the oviductal mucosal folds and are lined by both ciliated and secretory cells. Ciliated cells are characterized by a few microvilli and prominent cilia in the apical membranes. A prominent feature of the secretory cell is the presence of secretory granules in the supranuclear region. The size, shape, and electron density of these granules vary markedly. The secretory product is released mainly by exocytosis into the oviductal lumen, where it appears as flocculent material. The unique structure in the base of the epithelium, the basal border of the cell -- the basal lamina -- and a blood vessel layer, is presumed to be a important barrier, by which the nourishment exchange and the microenvironment maintenance are ensured. The gland cell is presented with numerous, round, membrane-bound secretory granules of moderate to high electron densities. We divide these granules into three types according to their appearance: (1) membrane bounded granules with high-homogeneous electron density, (2) membrane bounded granules with moderate-homogeneous electron density, (3) membrane bounded, electron dense granules with concentric structures. These granules are presented as different stages of the secretions in the gland cell. The junction complexes are markedly distributed between cells, which are important in keeping stability and the microenvironment maintenance of the sperm storage tubules. Sperm stored in the tubules are heterogeneous in cytology. In addition to the mature sperm in the lumen, sperm with large chromatic granules are found, which are presumed to be immature sperm and are being in the process of nuclear condensation. Several spermatozoa in the tubules are exhibited with definitive indications of degeneration of the nuclei. The nuclear volume increases. The electron density of the central cores in mitochondria declines, combined with the deterioration of concentric membrane structure. Those changes are possibly due to the long time storage of the sperm in sperm storage tubules, and the leakage of reactive oxygen species is suggested to be a major cause. We conclude that the ultrastructure character of sperm storage in the oviduct of Trionyx sinensis is unique, in addition to having a basal function in secretion and the cilia swing, the tubules also provide an available microenvironment for the sperm to long time stored. The degenerative sperm in the tubules might be related to paternity-specific reproductive adaptations, and the sperm competition might occur during long time storage.

Immunohistochemical demonstration of S-100 protein in epithelial cells of bovine oviduct.

The present study deals with an immunohistochemical localization of S-100 protein in the bovine oviduct. The epithelium of the infundibulum, ampulla and isthmus showed a positive staining for S-100 protein. The immunoreactivity for S-100 was observed both in the ciliated and nonciliated (secretory) cells of the oviductal epithelium at any stages of the estrous cycle. The immunoreactivity was also found in nervous elements and endothelial cells of blood vessels. No cell outside these cells showed any immunoreactivity for S-100. Although the functional significance of S-100 protein in the oviductal epithelium remains to be elucidated, the present results introduce new perspectives into the investigation of function and localization of S-100 protein.

Changes in oviducal vascularity during the reproductive cycle of three oviparous lizards (Eumeces obsoletus, Sceloporus undulatus and Crotaphytus collaris).

Histologically derived estimates and ink suspension vascular casts were used to examine oviducal vascular changes. Vascularity peaked during gravidity and was correlated with maximal plasma progesterone concentrations. The vascular increase in the oviducal tissue was attributed exclusively to increased capillary densities. The greatest change occurred in the anterior uterus where incubation and egg shell secretion occur. Similar patterns of change in vascularity occurred in the infundibulum, although not as extreme as that seen in the anterior uterus, whereas no significant alterations were noted in the posterior uterus. These modifications mimic the pattern of vascular change occurring in viviparous lizards during simple placentation. We suggest that major changes in uterine vascularity may not be required for the evolution of simple chorioallantoic placentae in lizards.