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Polyunsaturated fatty acids in heart muscle and alpha 1-adrenoceptor binding properties.
Skúladóttir, G V; Schiöth, H B; Gudbjarnason, S.
Afiliación
  • Skúladóttir GV; University of Iceland, Science Institute, Reykjavík.
Biochim Biophys Acta ; 1178(1): 49-54, 1993 Jul 28.
Article en En | MEDLINE | ID: mdl-8392377
Modifications of membrane phospholipids and binding characteristics of adrenoceptors by hydrocortisone and epinephrine were examined in sarcolemmal preparation from rat heart muscle. The influence of hydrocortisone and epinephrine on the fatty acid composition of membrane phospholipids and the affinity (1/Kd) and number of binding sites (Bmax) of alpha 1- and beta-adrenoceptors was studied in male Wistar rats treated daily for 7 days with the hormones. The alpha 1- and beta-adrenoceptors were characterized by using the antagonist ligands [3H]prazosin and [3H]dihydroalprenolol, respectively. Administration of the hormones altered significantly the composition of fatty acids, decreased linoleic acid (18: 2(n-6)) level of both phosphatidylcholine and phosphatidylethanolamine, and increased arachidonic acid (20: 4(n-6)) level of phosphatidylcholine and docosahexaenoic acid (22: 6(n-3)) level in both phosphatidylcholine and phosphatidylethanolamine. The binding sites of alpha 1-adrenoceptors were of high affinity in the control group. Following administration of the hormones Kd of alpha 1-adrenoceptors increased markedly. The number of alpha 1-adrenoceptors binding sites did not change significantly due to the hormones. In contrast, while the hormone treatments did not alter the affinity of the beta-adrenoceptors the number of binding sites were significantly decreased by the hormones. The results indicate that the decrease in affinity of alpha 1-adrenoceptors and the down-regulation of beta-adrenoceptors is accompanied by alteration in percentage fatty acid compositions of phosphatidylethanolamine and phosphatidylcholine in cardiac muscle.
Asunto(s)
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Colección: 01-internacional Base de datos: MEDLINE Asunto principal: Receptores Adrenérgicos alfa / Ácidos Grasos Insaturados / Miocardio Límite: Animals Idioma: En Revista: Biochim Biophys Acta Año: 1993 Tipo del documento: Article Pais de publicación: Países Bajos
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Colección: 01-internacional Base de datos: MEDLINE Asunto principal: Receptores Adrenérgicos alfa / Ácidos Grasos Insaturados / Miocardio Límite: Animals Idioma: En Revista: Biochim Biophys Acta Año: 1993 Tipo del documento: Article Pais de publicación: Países Bajos