Preliminary studies of rat pancreas duct epithelial cells in an acute inflammatory wound healing model.
Explore the source record for details and available documents.
Biomedical subjects
Publications and source records attributed to R Sicard.
Explore the source record for details and available documents.
Atrial natriuretic peptide (ANP) is a hormone involved in fluid and blood pressure homeostasis. We studied the effects of left-to-right shunting through a patent ductus arteriosus on blood pressure changes and plasma ANP concentrations in newborn piglets. In five experimental piglets, the ductus arteriosus was bathed with PGE1 and infiltrated with formalin to maintain its patency. In four age-matched control piglets, the ductus arteriosus was ligated. Plasma ANP concentrations and blood pressure determinations were obtained prior to (base-line) and 25 +/- 1 h (day 1), and 48 +/- 1 h (day 2) after surgery. Radionuclide-microsphere determinations of left-to-right patent ductus arteriosus shunts were performed on days 1 and 2 in the 5 piglets with a patent ductus arteriosus. Plasma ANP concentrations were significantly elevated in the left atrium on day 1 and the right atrium on day 2 in the PDA piglets. No correlation was demonstrated between plasma ANP concentrations and right or left atrial pressures. We conclude that left and right plasma atrial ANP concentrations are significantly elevated in newborn piglets with left-to-right patent ductus arteriosus shunts.
1. Synthetic cholesteryl esters with various acyl chain length (C2-C18) are hydrolysed by several enzymes in hamster liver. 2. The comparison of effect of inhibitors, divalent cations, detergents, pH and substrate specificity allows discrimination between four enzymes hydrolyzing cholesteryl esters, which are characterized by their enzymatic properties, two cholesterol esterases (resistant to E600) hydrolyzed medium- and long-chain cholesteryl esters, whereas short-chain cholesteryl esters were hydrolyzed by two different carboxylesterases (dramatically inhibited by E600). 3. The acid cholesterol esterase (identical to the lysosomal lipase) exhibited a pH optimum at pH 5.0 and is activated by 1 mM taurocholate. 4. The alkaline cholesterol esterase (pH optimum 7.5) is not very sensitive to the tested effectors. 5. Both acid and alkaline carboxylesterases (pH optima 5.5 and 7.5), were characterized by their strict dependence on divalent cations (Mn2+ or Mg2+). 6. The acid carboxylesterase was inhibited by increasing concentrations of Triton X-100, whereas the alkaline carboxylesterase was dramatically activated by 2 g/l Triton X-100. 7. No significant difference was observed in activities of cholesterol esterases or carboxylesterases between normal and FEC hamster livers.