In:
American Journal of Physiology-Renal Physiology, American Physiological Society, Vol. 292, No. 1 ( 2007-01), p. F415-F422
Abstract:
In the current experiments, we determined the response of plasma renin concentration (PRC) to acute intraperitoneal administration of furosemide (40 mg/kg), hydralazine (2 mg/kg), isoproterenol (10 mg/kg), candesartan (50 μg), or quinaprilate (50 μg) in conscious wild-type (WT) and cyclooxygenase (COX)-2−/− mice on three different genetic backgrounds (mixed, C57BL/6, 129J). PRC was measured in plasma obtained by tail vein puncture. Basal PRC was significantly lower in COX-2−/− than WT mice independent of genetic background (51, 10, and 17% of WT in mixed, 129J, and C57BL/6). All five acute interventions caused significant increases of PRC in both COX-2+/+ and −/− mice, but the response was consistently less in COX-2-deficient mice (e.g., ΔPRC in ng ANG I·ml −1 ·h −1 caused by furosemide, isoproterenol, hydralazine, quinaprilate, or candesartan 4,699 ± 544, 3,534 ± 957, 2,522 ± 369, 9,453 ± 1,705, 66,455 ± 21,938 in 129J WT, and 201 ± 78, 869 ± 275, 140 ± 71, 902 ± 304, 2,660 ± 954 in 129J COX-2−/−). A low-NaCl diet and enalapril for 1 wk caused a 14-fold elevation of PRC in COX-2−/− mice and was associated with a greatly increased PRC response to acute furosemide (ΔPRC 201 ± 78 before and 15,984 ± 2,397 after low Na/enalapril). As measured by radiotelemetry, blood pressure and heart rate responses to furosemide, hydralazine, isoproterenol, candesartan, or quinaprilate were not different between COX-2 genotypes. In conclusion, chronic absence of COX-2 reduces renin expression, release, and PRC and is associated with a reduced ability to alter PRC during acute stimulation regardless of the nature of the stimulus. COX-2 activity does not appear to be a mandatory and specific requirement for furosemide-stimulated renin secretion.
Type of Medium:
Online Resource
ISSN:
1931-857X
,
1522-1466
DOI:
10.1152/ajprenal.00317.2006
Language:
English
Publisher:
American Physiological Society
Publication Date:
2007
detail.hit.zdb_id:
1477287-5
