Acharya L Shobha Kumari, Ovais M
Department of Biosciences, Barkatullah University, Bhopal 462026, India.
Indian J Exp Biol. 2007 Nov;45(11):984-91.
Effects of specific and non-specific adrenoceptor agonists and antagonists were examined on the isolated scale melanophores of O. mossambica in physiological Ringer solution. The responses were recorded as melanophore size index. It was observed that adrenaline, nor-adrenaline, phenylpropanolamine, clonidine and phenylepherine induced melanosome aggregation in a dose-dependent manner. Denervation of the fish melanophores increased the sensitivity of the melanophores to adrenaline but not to nor-adrenaline. Phentolamine (3.55 x 10(-5) M), prazosin (2.38 x 10(-5) M) and yohimbine (2.821 x 10(-5) M) significantly inhibited the aggregatory responses of the fish melanophores to adrenaline, nor-adrenaline, clonidine and phenylepherine. The blocking effect of yohimbine was significantly higher than that of prazosin. It is concluded that the effect of adrenaline is directly mediated through the receptors and alpha2 adrenoceptors are predominantly involved in the aggregatory responses of this fish melanophores, while alpha1 adrenoceptors presence has been indicated.
在生理林格氏溶液中，研究了特异性和非特异性肾上腺素能受体激动剂及拮抗剂对莫桑比克罗非鱼离体鳞片黑素细胞的影响。以黑素细胞大小指数记录反应。观察到肾上腺素、去甲肾上腺素、苯丙醇胺、可乐定和去氧肾上腺素以剂量依赖性方式诱导黑素体聚集。对鱼黑素细胞进行去神经支配可增加黑素细胞对肾上腺素的敏感性，但对去甲肾上腺素的敏感性无影响。酚妥拉明（3.55×10⁻⁵ M）、哌唑嗪（2.38×10⁻⁵ M）和育亨宾（2.821×10⁻⁵ M）显著抑制鱼黑素细胞对肾上腺素、去甲肾上腺素、可乐定和去氧肾上腺素的聚集反应。育亨宾的阻断作用明显高于哌唑嗪。得出结论：肾上腺素的作用是通过受体直接介导的，α₂肾上腺素能受体主要参与这种鱼黑素细胞的聚集反应，同时表明存在α₁肾上腺素能受体。
