PECULIAR ALPHA-ADRENOCEPTORS PROMOTE PIGMENT AGGREGATION IN THE TELEOST, SYNBRANCHUS-MARMORATUS MELANOPHORES

被引:7
作者
ABRAO, MS [1 ]
VISCONTI, MA [1 ]
BRITTO, ALM [1 ]
CASTRUCCI, AMD [1 ]
机构
[1] UNIV SAO PAULO,INST BIOCIENCIAS,DEPT FISIOL GERAL,CP 11176,BR-05499 SAO PAULO,BRAZIL
来源
COMPARATIVE BIOCHEMISTRY AND PHYSIOLOGY C-PHARMACOLOGY TOXICOLOGY & ENDOCRINOLOGY | 1991年 / 99卷 / 1-2期
关键词
D O I
10.1016/0742-8413(91)90091-7
中图分类号
Q5 [生物化学]; Q7 [分子生物学];
学科分类号
071010 ; 081704 ;
摘要
1. In S. marmoratus melanophores, the DRC to norepinephrine (NE) was shifted to the right (30-fold) by yohimbine 10(-6) M, but was not affected by labetalol. Methoxamine and phenylephrine were inactive, even in the presence of propranolol and yohimbine. 2. Clonidine was also inactive, but induced a dose-dependent pigment aggregation (ED50 = 1.75 x 10(-6) M), which was diminished (10-fold) by yohimbine 10(-6) M, within Poecilia reticulata melanophores. 3. 4-Bromophenacyl bromide, neomycin sulphate, dibucaine, H-7 and lithium chloride did not affect the DRC to NE. Beta-glycerophosphate 10(-2) M shifted to the right (10-fold) the DRC to NE. 4. The adrenoceptors mediating melanosome aggregation within S. marmoratus melanophores can not be defined by the classical alpha2-agonists, but their activation is unrelated to the DG/IP3 pathway. These peculiar adrenoceptors may be structurally and pharmacologically different from the two, alpha1 and alpha2, subtypes.
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页码:147 / 151
页数:5
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