Effects of atrial natriuretic peptide and toad heart extract on isolated toad Bufo arenarum aortic rings
| Autor: | Alfredo Coviello, MaráPeral de Bruno |
|---|---|
| Rok vydání: | 1992 |
| Předmět: |
Male
medicine.medical_specialty Vasopressin Contraction (grammar) Muscle Relaxation chemistry.chemical_element Aorta Thoracic Toad In Vitro Techniques Calcium Muscle Smooth Vascular Norepinephrine Endocrinology Atrial natriuretic peptide medicine.artery biology.animal Internal medicine medicine Animals Aorta biology Tissue Extracts urogenital system Angiotensin II Heart Calcium Channel Blockers Arginine Vasopressin chemistry Bufo arenarum Potassium cardiovascular system Animal Science and Zoology Atrial Natriuretic Factor hormones hormone substitutes and hormone antagonists Muscle Contraction circulatory and respiratory physiology |
| Zdroj: | General and Comparative Endocrinology. 88:424-433 |
| ISSN: | 0016-6480 |
| DOI: | 10.1016/0016-6480(92)90237-e |
| Popis: | The vascular effects of synthetic atrial natriuretic peptide (ANP) (rANP-99-126), and toad heart extract (THE) were examined on isolated toad aortic rings from the toad Bufo arenarum. ANP inhibited contraction produced by human angiotensin 11 (AT 11), norepinephrine (NE), and arginine vasopressin (AVP) in isolated toad aortic rings. The present data show that a relaxant effect of ANP could be obtained also in the noncontracted aortic smooth muscle of the toad if it had been previously challenged with AT 11 or NE and allowed to return to the original basal tension. Bufo arenarum THE was able to relax the AT II-induced contraction in toad aortic rings. In toad arteries contracted with 10−6 M AT II, ANP produced a dose-dependent relaxation with a half-maximal inhibitory concentration IC50, of 1.2 × 10−8 M. ANP was not effective in relaxing contraction induced by high K+. The vasorelaxant effect of ANP on AT I1-induced contraction was significantly increased in Ca2+-free medium containing 3 mM ethylene glycol bis(β-aminoethyl ether) N,N,N′,N′tetraacetic acid (EGTA-Ringer) or by pretreatment with the calcium antagonist, diltiazem (DIL). The vasorelaxant effect of ANP on basal tension after treatment with AT II was also obtained in absence of extracellular calcium (EGTA-Ringer). These results show that Bufo arenarum contains ANP-like material and that the ANP relaxant action in the toad aorta is similar to that in mammals. |
| Databáze: | OpenAIRE |
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