The effect of intravenously administered vasoconstrictor (nor-epinephrine, ephedrine and posterior pituitary hormone) and vasodilator (papaverine, nicotinic acid and theophylline) drugs on the choroidal blood flow of rabbits was studied by the apparatus based on the principle of Grayson´s internal calorimetry.
Thermistors, as the sensing elements, were introduced into the suprachoroidal space ,of rabbits eye, and continuous determinations were performed up to 60 minutes after the administration.
Papaverine(2mg/kg), theophylline (5mg/kg and 50 mg/kg) and nicotinic acid (2Zmg/kg and 50 mg/kg) produced significant increase in the blood flow, papaverine and theophylline being the most powerful.
Among the vasoconstrictor drugs, posterior pituitary hormone produced profound and prolonged decrease in the blood flow, whereas nor-epinephrine and ephedrine increase the blood flow following transient decreases in the blood flow.
The relationships between blood pressure, intraocular pressure and choroidal blood flow, and the suggestions in the therapeutic applications to human eye were discussed.
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