In addition to concentrating bile, the gallbladder secretes chloride (Cl-) and mucus into ifs lumen. We recently observed that gallbladder Cl- secretion is increased in prairie dogs during the formation of cholesterol...
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In addition to concentrating bile, the gallbladder secretes chloride (Cl-) and mucus into ifs lumen. We recently observed that gallbladder Cl- secretion is increased in prairie dogs during the formation of cholesterol crystals, a period of altered mucosal prostaglandin synthesis. Pathologic Cl- secretion is characteristic of other epithelial disorders such as cystic fibrosis and hypercalciuric nephrolithiasis and may be important in gallstone pathogenesis. We hypothesized that concentrations of endogenous prostaglandin E-2 (PGE(2)) found during experimental gallstone formation may mediate increased Cl- secretion by prairie dog gallbladder, Prairie dog gallbladders were harvested by cholecystectomy and mounted in Ussing chambers. Unidirectional transepithelial Cl-, Na+, and H2O fluxes were measured before and after inhibition of endogenous prostaglandin synthesis with 10 mu mol/L indomethacin. Gallbladders were then exposed to increasing concentrations of PGE(2) to a maximal dose of 1 mu mol/L, as found in animals with gallstones. Standard electrophysiologic parameters were recorded simultaneously. Indomethacin increased mucosal resistance and stimulated gallbladder Na+ and CI- absorption. These effects were rapidly reversed by PGE(2). PGE(2) promoted Cl- secretion and decreased mucosal Na+ absorption at concentrations found in the gallbladder bile of animals with gallstones. Endogenous prostaglandin metabolism modulates gallbladder CI- secretion and may promote changes in Cl- transport associated with cholelithiasis.
In this study, we determined the histomorphological changes in different regions of the oviduct (fimbriae, infundibulum, ampullae and isthmus) during early pregnancy (days 1-4) of the rabbit. It was observed that the ...
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In this study, we determined the histomorphological changes in different regions of the oviduct (fimbriae, infundibulum, ampullae and isthmus) during early pregnancy (days 1-4) of the rabbit. It was observed that the number of secretory cells (PAS-positive cells) diminished in the fimbriae during the first 4 days of pregnancy with the corresponding increase in the number of non-secretory cells (PAS-negative cells). In contrast, there was an increase in the number of PAS-positive cells in the isthmus during early pregnancy. In both the infundibulum and the ampullae the number of PAS-positive cells was increased on day 3. A significant decrease in the height of the epithelium was observed in the fimbriae during early pregnancy. On the contrary, a significant increase in this parameter was observed in the isthmus during the first 3 days of pregnancy. A slight decrease in the height of the epithelium was observed in the infundibulum on day 4 of pregnancy, while in the ampullae it was significantly increased on days 1 and 3. The overall results indicate that during early pregnancy there is a selective modification in the histomorphological characteristics of the different regions of the rabbit oviduct.
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