Adrenoreceptor-mediated effect of neuropeptide Y decreases cardiac inotropic responses
| Autor: | Nobby D. Woo, David S.C. Lam, Pallab K. Ganguly, Vincenzo Panagia, Jean-Anne Hays |
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| Rok vydání: | 1994 |
| Předmět: |
Male
Phosphatidylinositol 4 5-Diphosphate Langendorff heart medicine.medical_specialty Adrenergic receptor Inositol 1 4 5-Trisphosphate In Vitro Techniques Rats Sprague-Dawley Contractility Phenylephrine Phosphatidylinositol Phosphates Postsynaptic potential Internal medicine mental disorders medicine Animals Neuropeptide Y Receptor Molecular Biology Sarcolemma Chemistry Myocardium Isoproterenol Prazosin Cell Biology Receptors Adrenergic alpha Neuropeptide Y receptor Myocardial Contraction humanities Rats Endocrinology Type C Phospholipases cardiovascular system Calcium Ca(2+) Mg(2+)-ATPase Sodium-Potassium-Exchanging ATPase medicine.drug |
| Zdroj: | Biochimica et Biophysica Acta (BBA) - Molecular Cell Research. 1222:457-463 |
| ISSN: | 0167-4889 |
| DOI: | 10.1016/0167-4889(94)90054-x |
| Popis: | The effect of neuropeptide Y on the number and affinity of catecholamine receptors in the ventricular myocardium was investigated. Receptor binding studies showed that incubation of cardiac membrane in the presence of neuropeptide Y (NPY, 10−7 M) decreased the number of α/β-adrenoceptor binding sites (Bmax) without affecting the affinity (KD) of these receptors. Although not able to modulate the contractility by itself, NPY was able to decrease the positive inotropic effects of phenylephrine and isoproterenol in the isolated, perfused myocardium. Ca 2+ Mg 2+ - ATPase activity, measured from the sarcolemma, sarcoplasmic reticulum and myofibrils, was unaltered whereas the activity of sarcolemmal Na + K + - ATPase was decreased when NPY was included in the media. On the other hand, NPY was shown to increase the phosphoinositide-phospholipase C associated with the sarcolemma. These findings support the hypothesis that NPY modulates postsynaptic adrenergic receptors in the myocardium and can affect the adrenergic-induced, inotropic response. |
| Databáze: | OpenAIRE |
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