Comparison of the development of tolerance to nitroglycerin in aortic preparations isolated from non-diabetic and diabetic rats.

To clarify whether or not tolerance to nitroglycerin is developed more easily in a diabetic than in a non-diabetic state, the effects of nitroglycerin on aortic preparations isolated from diabetic and non-diabetic rats were examined and compared with those of nicorandil, which has been known to develop less tolerance than does nitroglycerin. Contractile responses to norepinephrine, relaxant responses to nitroglycerin and nicorandil, and the tolerance development to nitroglycerin were found to be no different between diabetic and non-diabetic aortic preparations. N-Acetylcysteine preincubated together with nitroglycerin prevented the tolerance development to nitroglycerin in non-diabetic but not in diabetic aortic preparations. The results suggest that the tolerance to nitroglycerin is developed in the diabetic as well as in the non-diabetic state.