Abstract
1. Nitrate tolerance is a clinical problem. The cause is not known but it has been suggested that tolerance to organic nitrates occurs within the blood vessels to reduce sensitivity to the drug. We have determined the sensitivity of human forearm resistance vessels and veins to glyceryl trinitrate (GTN) at the beginning and end of a 7 day period of GTN administration in healthy volunteers using a clinically relevant dose of transdermal drug. 2. Eight healthy volunteers completed the study which entailed measurement of change in forearm venous compliance and change in forearm blood flow following intraarterial infusions of two doses of glyceryl trinitrate (0.5 and 2.0 micrograms min-1) before, after 2 h and after 7 days of transdermal GTN administration using one 10 mg patch each 24 h. 3. Changes in venous compliance and blood flow were measured by venous occlusion plethysmography using a basal infusion of noradrenaline (1 microgram min-1) to increase venous tone. 4. Noradrenaline produced the expected decrease in forearm blood flow and venous compliance. The effect of locally infused GTN on venous compliance and forearm blood flow was similar on the three study days. In particular there was no significant difference in the response to GTN following 7 days transdermal administration compared with that after 2 h. 5. We conclude from this study that local vascular tolerance to GTN is unlikely to explain the clinical problem of nitrate tolerance, and that other mechanisms such as neurohumoral activation may be important.
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- Aellig W. H. Methods for studying drug effects on superficial human veins. Methods Find Exp Clin Pharmacol. 1985 Jun;7(6):321–324. [PubMed] [Google Scholar]
- Bauer J. A., Fung H. L. Concurrent hydralazine administration prevents nitroglycerin-induced hemodynamic tolerance in experimental heart failure. Circulation. 1991 Jul;84(1):35–39. doi: 10.1161/01.cir.84.1.35. [DOI] [PubMed] [Google Scholar]
- Bayley S., Valentine H., Bennett E. D. The haemodynamic responses to incremental doses of intravenous nitroglycerin in left ventricular failure. Intensive Care Med. 1984;10(3):139–145. doi: 10.1007/BF00265803. [DOI] [PubMed] [Google Scholar]
- Benjamin N., Cockcroft J. R., Collier J. G., Dollery C. T., Ritter J. M., Webb D. J. Local inhibition of converting enzyme and vascular responses to angiotensin and bradykinin in the human forearm. J Physiol. 1989 May;412:543–555. doi: 10.1113/jphysiol.1989.sp017630. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Curry S. H., Kwon H. R., Perrin J. H., Culp J. R., Pepine C. J., Yu W. Nitroglycerin levels after administration via transdermal therapeutic system or nitroglycerin ointment. Lancet. 1984 Jun 9;1(8389):1297–1297. doi: 10.1016/s0140-6736(84)92476-0. [DOI] [PubMed] [Google Scholar]
- Elkayam U. Tolerance to organic nitrates: evidence, mechanisms, clinical relevance, and strategies for prevention. Ann Intern Med. 1991 Apr 15;114(8):667–677. doi: 10.7326/0003-4819-114-8-667. [DOI] [PubMed] [Google Scholar]
- GREENFIELD A. D., PATTERSON G. C. Reactions of the blood vessels of the human forearm to increases in transmural pressure. J Physiol. 1954 Sep 28;125(3):508–524. doi: 10.1113/jphysiol.1954.sp005177. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Katz R. J., Levy W. S., Buff L., Wasserman A. G. Prevention of nitrate tolerance with angiotension converting enzyme inhibitors. Circulation. 1991 Apr;83(4):1271–1277. doi: 10.1161/01.cir.83.4.1271. [DOI] [PubMed] [Google Scholar]
- Mason D. T., Braunwald E. The effects of nitroglycerin and amyl nitrite on arteriolar and venous tone in the human forearm. Circulation. 1965 Nov;32(5):755–766. doi: 10.1161/01.cir.32.5.755. [DOI] [PubMed] [Google Scholar]
- Needleman P., Jakschik B., Johnson E. M., Jr Sulfhydryl requirement for relaxation of vascular smooth muscle. J Pharmacol Exp Ther. 1973 Nov;187(2):324–331. [PubMed] [Google Scholar]
- Needleman P., Johnson E. M., Jr Mechanism of tolerance development to organic nitrates. J Pharmacol Exp Ther. 1973 Mar;184(3):709–715. [PubMed] [Google Scholar]
- WOOD J. E., ECKSTEIN J. W. A tandem foream plethysmograph for study of acute responses of the peripheral veins of man: the effect of environmental and local temperature change, and the effect of pooling blood in the extremities. J Clin Invest. 1958 Jan;37(1):41–50. doi: 10.1172/JCI103583. [DOI] [PMC free article] [PubMed] [Google Scholar]