Vasoconstrictor action of angiotensin I-convertase and the synthetic substrate (Pro11,D-Ala12)-angiotensin I
| Autor: | Joseph T. MacAndrew, H A Johnson, Michael L. Mangiapane, D J Cushing, S S Ellery, A. L. Rauch, Delvin R. Knight, K. W. Hoover, R A Buchholz, William P. Magee |
|---|---|
| Rok vydání: | 1994 |
| Předmět: |
Male
medicine.medical_specialty Contraction (grammar) Captopril Blood Pressure In Vitro Techniques Potassium Chloride Chymases Dogs Internal medicine Renin–angiotensin system Internal Medicine medicine Animals Vasoconstrictor Agents Mesenteric arteries Dose-Response Relationship Drug Chemistry Serine Endopeptidases Chymase Callithrix Mesenteric Arteries medicine.anatomical_structure Endocrinology Losartan cardiovascular system Female medicine.symptom Angiotensin I hormones hormone substitutes and hormone antagonists Vasoconstriction Blood vessel medicine.drug |
| Zdroj: | Hypertension (Dallas, Tex. : 1979). 23(6 Pt 2) |
| ISSN: | 0194-911X |
| Popis: | A chymase (also referred to as angiotensin I-convertase) specific for the conversion of angiotensin (Ang) I to Ang II has been identified in human heart. This serine protease is also present in dog and marmoset vasculature. We examined the vasoconstrictor effects of Ang II putatively generated from an angiotensin-converting enzyme (ACE)-resistant convertase synthetic substrate (SUB) in vivo and in vitro. In marmosets, SUB (7 to 700 micrograms/kg i.v.) or Ang I (0.1 to 30 micrograms/kg) caused similar dose-dependent increases in mean arterial pressure (10 to 100 mm Hg) and decreases in heart rate. Pressor effects of SUB were slightly attenuated at low (but not high) doses by captopril (CAP, 1 mg/kg i.v.) and blocked by losartan (5 mg/kg i.v.); in contrast Ang I pressor effects were substantially blocked by both. In isolated canine superior mesenteric artery, Ang I-induced contraction was eliminated by losartan and reduced but not eliminated by 10 mumol/L CAP. When combined with the serine protease inhibitor chymostatin, CAP eliminated Ang I-induced contraction, but chymostatin alone had no effect. SUB-induced contraction was not blocked by CAP but was equally blocked by chymostatin (25 mumol/L) alone or by the combination of CAP (10 mumol/L) and chymostatin (25 mumol/L); losartan (10 mumol/L) eliminated SUB-induced responses. Previous studies have suggested that Ang I-convertase is important for production of Ang II in the heart. Our results are consistent with a potential role for Ang I-convertase in the production of Ang II in the vasculature, resulting in Ang II-mediated vasoconstriction. |
| Databáze: | OpenAIRE |
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