[Effect of pretreatment with the alpha-adrenoblocker phentolamine and the beta-adrenoblocker inderal on the...

The effect of the pretreatment with the alpha-adrenoblocker phentolamine and the beta-adrenoblocker inderal was studied on the disturbances of contractile function and adrenoreactivity which occurred after exposure to emotional-painful stress. The pretreatment of the animals exposed to emotional-painful stress with phentolamine prevented to a considerable degree the depression of portal vein contractility and raised adrenoreactivity of the smooth muscle that dramatically fell after emotional-painful stress to the basic level. Administration of inderal did not prevent the stress-induced disturbances. The data obtained suggest that the stress-induced injuring effect of catecholamine high concentrations is mediated via alpha-adrenoreceptors of portal vein smooth muscles.