Urinary and renal kallikrein in hypertensive fawn-hooded (FH/Wjd) rats
Gilboa, N.; Rudofsky, U.; Magro, A.
Laboratory Investigation; a Journal of Technical Methods and Pathology 50(1): 72-78
1984
ISSN/ISBN: 0023-6837 PMID: 6363817 Document Number: 240628
Urinary excretion of kallikrein (UKal), sodium, potassium, protein, and creatinine, as well as the kidney content of kallikrein and renin, was studied in spontaneously hypertensive FH/Wjd (FH) male and female rats and in age- and sex-matched normal Wistar rats. With the exception of 1-month-old rats UKal excretion was significantly lower in FH rats than in Wistar rats. FH females also excreted less UKal than Wistar females. No UKal inhibitor or increased degradation of this enzyme in the urine of FH rats was detected. There was no difference in creatinine clearance, blood urea nitrogen, or serum electrolytes, and calcium between 5-month-old FH and Wistar males. Wistar rat kidneys contained about twice as much kallikrein as FH rat kidneys. From the age of 2 months FH males excreted more sodium, as well as urine, than all other groups. No differences in potassium excretion were observed. Only FH males, 4 months and older, developed proteinuria. FH males and females became hypertensive at the ages of 2 and 4.5 months, respectively. Plasma renin activity, as well as renal renin activity, was significantly lower in FH than in Wistar males. In conclusion, the decrease in UKal activity which precedes the onset of hypertension suggests that the abnormality in the renal kallikrein system may be involved in the pathogenesis of hypertension in FH rats.