A kallikrein-like enzyme in the aorta of normotensive and hypertensive rats.
We evaluated whether vascular kallikrein is altered in rats with genetic or experimental hypertension. Group 1 was infused intraperitoneally with angiotensin II (Ang II) or vehicle for 4 weeks; group 2 was injected subcutaneously with deoxycorticosterone (75 mumol/kg once a week) or vehicle for 4 weeks; group 3 consisted of uninephrectomized rats on high sodium intake given deoxycorticosterone or vehicle; and group 4 consisted of spontaneously hypertensive rats (SHR) and Wistar-Kyoto (WKY) rats. Active and total kallikrein activity was measured in abdominal aortic homogenates using an amidolytic assay. Ang II increased systolic blood pressure at a dose of 400 nmol/kg per day (146 +/- 6 versus 123 +/- 3 mm Hg in controls, P < .01) but not at 80 nmol/kg per day. Deoxycorticosterone did not increase blood pressure except in uninephrectomized rats on high salt (173 +/- 6 versus 135 +/- 4 mm Hg in controls, P < .01). Blood pressure averaged 194 +/- 2 mm Hg in SHR and 123 +/- 3 mm Hg in WKY rats. Vascular kallikrein was similar in rats given Ang II or vehicle. In deoxycorticosterone-treated rats total kallikrein was higher than in controls (9.2 +/- 0.8 versus 3.5 +/- 0.1 pkat/mg protein, P < .05), whereas active kallikrein did not differ (0.09 +/- 0.04 versus 0.09 +/- 0.03 pkat/mg protein, P = NS). A similar pattern was observed in uninephrectomized deoxycorticosterone-treated rats (active, 0.09 +/- 0.03 versus 0.10 +/- 0.04, P = NS; total, 7.4 +/- 0.7 versus 4.1 +/- 0.2 pkat/mg protein, P < .05).(ABSTRACT TRUNCATED AT 250 WORDS)
Madeddu
P
P
Clinica Medica, University of Sassari, Italy.
Varoni
M V
MV
Demontis
M P
MP
Fattaccio
M C
MC
Parpaglia
P P
PP
Glorioso
N
N
D000804:Angiotensin II / Q000494:pharmacology; D000818:Animals; D001012:Aorta, Abdominal / Q000187:drug effects / Q000378:metabolism*; D001794:Blood Pressure / Q000187:drug effects; D003900:Desoxycorticosterone / Q000494:pharmacology; D006973:Hypertension / Q000378:metabolism*; D007610:Kallikreins / Q000378:metabolism*; D008297:Male; D009392:Nephrectomy; D051381:Rats; D011918:Rats, Inbred SHR; D011921:Rats, Inbred WKY; D017208:Rats, Wistar; D012016:Reference Values; D012965:Sodium Chloride / Q000494:pharmacology; D013599:Systole
D000804:Angiotensin II; D003900:Desoxycorticosterone; D012965:Sodium Chloride; D007610:Kallikreins