A kinetic study of rat salivary gland alkaline phosphatase and its inhibition by cadmium.
Alkaline phosphatase, confined to myoepithelial cells and blood capillaries in rat submandibular salivary gland (SSG), may participate in the regulation of salivary flow. To determine whether the alkaline phosphatase of SSG has unique properties, comparative kinetic and inhibition studies on enzymes from SSG, intestine and kidney were performed. The Km values (at optimal pH for each tissue) of 0.34, 0.55 and 0.49 mM with p-nitrophenylphosphate for the enzymes from SSG, kidney and small intestine respectively were similar. However, in the presence of cadmium the Ki values of 0.08 and 0.12 microM for the enzymes from SSG and kidney respectively were different from the value of 1.86 microM for the enzyme from small intestine. Differences in Ki values suggest differences in biochemical properties between the enzyme from small intestine and that isolated from SSG or kidney.
D000085:Acetates; D000469:Alkaline Phosphatase / Q000037:antagonists & inhibitors / Q000378:metabolism*; D000818:Animals; D002104:Cadmium / Q000494:pharmacology*; D007421:Intestine, Small / Q000201:enzymology; D007668:Kidney / Q000201:enzymology; D007700:Kinetics; D008297:Male; D051381:Rats; D011919:Rats, Inbred Strains; D013363:Submandibular Gland / Q000201:enzymology*; D015032:Zinc / Q000494:pharmacology
D000085:Acetates; D002104:Cadmium; C028031:cadmium acetate; D000469:Alkaline Phosphatase; D015032:Zinc