Please use this identifier to cite or link to this item: http://ahro.austin.org.au/austinjspui/handle/1/13623
Title: Dual inhibition of neutral endopeptidase and angiotensin-converting enzyme in rats with hypertension and diabetes mellitus.
Authors: Tikkanen, T;Tikkanen, Ilkka;Rockell, M D;Allen, Terri J;Johnston, Colin I;Cooper, Mark E;Burrell, Louise M
Affiliation: Department of Medicine, University of Melbourne, Austin and Repatriation Medical Centre, Heidelberg, Victoria, Australia.
Issue Date: 1-Oct-1998
Citation: Hypertension; 32(4): 778-85
Abstract: It has been suggested that combined inhibition of angiotensin-converting enzyme (ACE) and neutral endopeptidase (NEP) may lower blood pressure more effectively than either treatment alone, independent of the degree of salt and volume status or the activity of the renin-angiotensin system. The effects of NEP inhibition in hypertension associated with diabetes mellitus are largely unknown. We therefore compared ACE inhibition, NEP inhibition, and dual NEP/ACE inhibition in diabetic hypertensive rats. Spontaneously hypertensive rats (SHR) aged 9 to 10 weeks were injected with either streptozotocin (45 mg/kg) or citrate buffer and randomized to receive either the ACE inhibitor captopril (25 mg/kg BID), the NEP inhibitor SCH 42495 (30 mg/kg BID), the dual NEP/ACE inhibitor S 21402 (25 or 50 mg/kg BID), or vehicle by gavage for 4 weeks. A group of diabetic SHR was also allocated to receive the combination of SCH 42495 (30 mg/kg BID) and captopril (25 mg/kg BID). The degree of renal NEP inhibition was determined by autoradiography, and plasma renin activity (PRA) was determined by radioimmunoassay. In diabetic SHR, the dual NEP/ACE inhibitor (50 mg/kg BID), as well as the combination of the NEP inhibitor and the ACE inhibitor, reduced systolic blood pressure more effectively than the ACE inhibitor (P<0.001) or the NEP inhibitor (P<0.001) alone. In nondiabetic SHR, the dual NEP/ACE inhibitor and the ACE inhibitor were equally effective, while the NEP inhibitor had only slight blood pressure lowering effects. Relative heart weight decreased in parallel to the changes in blood pressure. Renal NEP was clearly inhibited (70% to 92%; P<0.001) by both the NEP inhibitor and the dual NEP/ACE inhibitor. Both the ACE inhibitor and the dual NEP/ACE inhibitor increased PRA, but the stimulating effect of dual NEP/ACE inhibition on PRA was less than that observed with ACE inhibition alone (P<0.05). Albuminuria in diabetic SHR was lower during treatment with both the dual NEP/ACE inhibitor (50 mg/kg BID) and the combination of NEP inhibition and ACE inhibition compared with vehicle treatment (P<0.05). In conclusion, the present study shows that hypertension in SHR with streptozotocin-induced diabetes is modulated by natriuretic peptides and thus is sensitive to NEP inhibition. The increased efficacy of dual NEP/ACE inhibition on blood pressure in diabetic SHR, compared with ACE or NEP inhibition alone, suggests that this therapeutic approach may prove beneficial in the treatment of hypertension associated with diabetes mellitus and other forms of volume-dependent hypertension.
Internal ID Number: 9774379
URI: http://ahro.austin.org.au/austinjspui/handle/1/13623
URL: http://www.ncbi.nlm.nih.gov/pubmed/9774379
Type: Journal Article
Subjects: Analysis of Variance
Angiotensin-Converting Enzyme Inhibitors.pharmacology.therapeutic use
Animals
Atrial Natriuretic Factor.blood
Blood Glucose
Blood Pressure.drug effects
Body Weight.drug effects
Captopril.pharmacology.therapeutic use
Diabetes Mellitus, Experimental.complications
Glomerular Filtration Rate.drug effects
Hypertension.complications.drug therapy
Male
Methionine.analogs & derivatives.pharmacology.therapeutic use
Neprilysin.antagonists & inhibitors
Propionates.pharmacology.therapeutic use
Rats
Rats, Inbred SHR
Renal Circulation.drug effects
Renin.blood
Sulfhydryl Compounds.pharmacology.therapeutic use
Appears in Collections:Journal articles

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