Effects of nicorandil and its congeners on musculature and vasculature of the dog trachea in situ.

M Maruyama, K Satoh, N Taira

Index: Arch. Int. Pharmacodyn. Ther. 258(2) , 260-6, (1982)

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Abstract

In anesthetized dogs, the tracheal vascular bed in situ was perfused with arterial blood through the cannulated cranial thyroid arteries. The effects of nicorandil, a coronary vasodilator, and its congeners (SG-212, GS-209 and SG-103; in which the nitroxy group of nicorandil was substituted for other groups) on the tracheal musculature and vasculature were examined. All drugs were injected intra-arterially. Nicorandil (10-300 micrograms), SG-212 (100 micrograms-3 mg), SG-209 (100 micrograms-3 mg) and SG-103 (100 micrograms-3 mg) all produced a decrease in tracheal tone elevated by neostigmine (tracheal dilatation) and an increase in tracheal blood flow (tracheal vasodilatation). Relative potencies of these effects were in the descending order: nicorandil greater than SG-212 = SG-209 = SG=103 in producing tracheal vasodilatation. These results suggest that nicorandil would also be a potential bronchodilator and that the nitrate site in nicorandil plays a role in potentiating the pharmacological activity of congeners of nicorandil.