Effects of hexamethonium, biperiden and phentolamine on the vasoconstrictive effects of oculomotor nerve stimulation in rabbits.

摘要: Abstract In rabbits intracranial stimulation of the oculomotor nerve causes vasoconstriction in anterior uvea and vasodilation choroid an attempt has been made to analyze mechanism involved vasoconstrictive response stimulation. The was stimulated unilaterally, regional blood flow determined both eyes using radioactively labelled microspheres. Hexamethonium bromide, a dose 40–80 mg/kg body weight, completely abolished iris ciliary processes. all parts tended be higher on side than control side. parasympatholytic agent biperiden lactate, 2·5–5 reduced iris, but no significant change observed alpha-adrenergic blocking phentolamine chloride, 10–15 weight had effect reversed A combination totally there increased processes results indicate that possibly adjacent structures caused release vasodilating vasoconstricting agents uvea. partly muscarinic, due miosis, receptors sensitive phentolamine. ganglion or ganglion-like receptors, somewhere between site effector cells, seem transmission impulses.