A direct radioimmunoassay of rat urinary kallikrein and comparison with other measures of urinary kallikrein activity.
A highly sensitive radioimmunoassay for rat urinary kallikrein (minimal detectable amount, 40 pg/tube) has been developed. The assay uses a sheep antibody (Keq = 3.25 X 10(10)M-1) against purified Sprague-Dawley rat urinary kallikrein in a final dilution of 1 : 1,200,000. The assay incorporates a convenient and inexpensive PEG technique for separation of free from bound antigen. Parallel standard curves with rat urine or kidney homogenates were obtained. No cross-reactivity with human or dog urine samples or purified human urinary kallikrein was seen. Correlations among this assay, an esterolytic method, and a kininogenase radioimmunoassay for kallikrein were highly significant, with only the esterolytic assay demonstrating any significant nonspecificity. The radioimmunoassay can detect changes in urinary kallikrein levels produced by a maneuver known to alter urinary kallikrein excretion.
D000818:Animals; D004950:Esterases / Q000378:metabolism; D007610:Kallikreins / Q000302:isolation & purification / Q000652:urine*; D007672:Kidney Cortex / Q000378:metabolism; D008297:Male; D011863:Radioimmunoassay / Q000379:methods; D051381:Rats; D014106:Tosylarginine Methyl Ester / Q000378:metabolism
D014106:Tosylarginine Methyl Ester; D004950:Esterases; D007610:Kallikreins