Decreased total and active urinary kallikrein in normotensive Dahl salt susceptible rats.
Abnormalities in the kallikrein-kinin system have been found in human and animal models of essential hypertension. The purpose of this study is to assess the kallikrein-kinin system in normotensive Dahl salt sensitive (S) and salt resistant (R) rats on a zero sodium diet. Urinary kallikrein was measured at 7 and 12 wk of age by different techniques. When kallikrein activity was assessed, by a kininogenase assay, S rats excreted 66% (P less than 0.001) and 75% (P less than 0.01) as much kallikrein as R rats at 7 and 12 wk of age. Using an artificial substrate method (Kabi S-2266), S rats excreted 30% (P less than 0.001) and 56% (P less than 0.05) as much kallikrein as R rats at 7 and 12 weeks, respectively. Using a technique to measure total kallikrein, S rats excreted 53% (P less than 0.001) and 65% (P less than 0.05) as much kallikrein as R rats at 7 and 12 wk of age. Normotensive S rats failed to increase maximally kallikrein activity or total kallikrein when the diet was switched from a .4% to a .0064% sodium chloride diet. There was no difference in inhibitors, as measured by the recovery of purified kallikrein added to S and R urine (56 +/- 21% vs. 53 +/- 13%). Km values for S and R urinary kallikrein were similar (3.1 +/- .5 X 10(-5) vs. 2.6 +/- .5 X 10(-5) M/liter). Trypsin-activatable kallikrein was equivalent in the S and R rats on the .0064% and .4% sodium chloride diet.(ABSTRACT TRUNCATED AT 250 WORDS)
D000818:Animals; D006973:Hypertension / Q000209:etiology / Q000235:genetics / Q000652:urine*; D007610:Kallikreins / Q000037:antagonists & inhibitors / Q000652:urine*; D007700:Kinetics; D008297:Male; D051381:Rats; D011922:Rats, Mutant Strains; D012965:Sodium Chloride / Q000494:pharmacology
D012965:Sodium Chloride; D007610:Kallikreins