[Blood flow changes in the optic nerve head of albino rabbits following intravenous administration of brovincamine fumarate, an improver of cerebral circulation and metabolism].

The blood flow changes in the optic nerve head in adult albino rabbits following intravenous administration of brovincamine fumarate, an improver of cerebral circulation and metabolism, were investigated employing the hydrogen clearance method. In the brovincamine fumarate (0.1 mg/kg)-administered group, the blood flow in the optic nerve head increased soon after injection and reached the maximal value of 124.2 +/- 7.3% against the value before injection, at 20 minutes after injection, followed by a gradual decrease in the blood flow. Statistical analysis showed a significant increase (p < 0.05) in the blood flow at 10 to 40 minutes after injection, compared with the value before injection in the brovincamine fumarate (0.1 mg/kg)-administered group, but no significant increases in the blood flow were observed in either the brovincamine fumarate (0.5 mg/kg)-administered group or the control group given no brovincamine fumarate throughout the course. No significant changes in the mean values of the blood pressure in the femoral artery, pulse rate, respiratory rate or rectal temperature were observed in any group through the experiment. To learn the mechanism of the different efficacy of the two doses, further studies are needed in light of the cyclic adenosine monophosphate (cyclic AMP) changes induced by brovincamine fumarate administration or in light of the receptor responsiveness to the drug concentration.