The effect of Nicorandil on chronic cerebral vasospasm

The present study is aimed at examining the therapeutic effect of Nicorandil on chronic vasospasm using beagle dogs subjected to a "two-haemorrhage" insult, as well as its dilatory effect on the PDA [phorbol-12,13 diacetate]-induced contraction of the canine basilar artery. 1. A total of 12 animals of either sex, weighing 7 to 12 kg, were assigned into saline control and Nicorandil-treated groups. Immediately after the second induction of subarachnoid haemorrhage (SAH), animals started to receive the agent via the venous route at the constant rate of 10 micrograms/kg/minute for six hours (day 3). On days 4, 5, and 6, the drug was given twice at the same rate for three hours. After the final angiograms, animals were sacrificed by exsanguination. 2. Using ring specimen of the canine basilar artery at a resting tension of 3 g, isometric tension was monitored to examine the effect of Nicorandil on PDA induced contraction. Nicorandil significantly ameliorated chronic vasospasm and inhibited PDA-induced contraction in a dose-dependent fashion. The present data indicate that Nicorandil provides a useful way of treating chronic vasospasm after SAH.