Abstract
The present study was designed to determine whether norepinephrine (NE) mediate endothelium-dependent relaxations in arteries of the pulmonary vasculature of cold-acclimated rats. Twenty male Sprague-Dawley rats comprising two groups (Cold-acclimated for 12 weeks at 6°C, CA; Warm-acclimated for 12 weeks at 24 °C, WA) were used. After anesthesia, the pulmonary artery (4 mm long) was isolated. Pulmonary artery with and without endothelium were suspended for isometric force measurements in a buffered salt solution. The doseresponse relations for the vascular responses to the isolated pulmonary artery to norepinephrine (NE), phenylephrine (PE) and acetylcholine (Ach) were determined and compared in the CA group and the WA group. In the CA group, the vascular sensitivities to NE and PE-induced contraction in the pulmonary artery was significantly lowered than that in the WA group. NE and PE-induced contractions were significandy greater in endotheliumdenuded compared with endothelium-intact arteries. These differences of contraction responses to NE and PE between arteries with widiout endothelium were significantly greater in the CA group than in the WA group. There was no significant difference between the pulmonary arterial response to Ach in the CA group and that in the WA group. Our data suggest that chronic exposure to cold show decreased NE and PE-induced contraction responses in isolated pulmonary arteries and may decrease NE-induced contraction responses due to enhancing NE-induced endodielium derived relaxing factor release via up-regulating endothelial α-adrenoceptors.
This is a preview of subscription content, log in via an institution to check access.
Similar content being viewed by others
References
Furchgott FR, Zawadzki JV. The obligatory role of endothelial cells in the relaxation of arterial smooth muscle by acetylcholine. Nature 1980;288: 373–6.
Roger AJ, Johns ML, Michael JP. Endothelium-dependent relaxation and cyclic GMP accumulation in rabbit pulmonary artery are selectively impaired by moderate hypoxia. Circ Res 1989;65: 1508–15.
Busch MA, Tucker A, Robertshaw D. Interaction between cold and altitude exposure on pulmonary circulation of cattle. J Appl Physiol 1985;58: 948–53.
Will DH, McMurtry IF, Reeves JT, Grover RF. Coldinduced pulmonary hypertension in cattle. J Appl Physiol 1978;45: 469–73.
Kashimura O. Effects of acute exposure to cold on pulmonary arterial blood pressure in awake rats. Jpn J Hyg 1993;48: 859–63.
Bryar BA, Fregly MJ, Field FP. Changes in vascular responsiveness following chronic exposure to cold in the rat. J Appl physiol 1983;55: 823–9.
Flaims SF, Hsieh ACL. Effects of cold acclimation on aadrenergic receptors of rabbit carotid artery. Gen Pharmacol 1979;10: 275–7.
Fregly MJ, Field FP, Nelson EL Jr. Effect of chronic exposure to cold on some responses to catecholamines. J Appl Physiol; 42: 349–54.
Hintz TH, Vatner DSF. Reactive dilation of large coronary arteries in conscious dogs. Circ Res 1984;54: 50–57.
Kaiser L, Hull SS, Sparks HV. Methylene blue and ETYA block flow-dependent dilation in canine femoral artery. Am J Physiol 1986;250: H974–81.
Kaneko K, Sunano S. Involvement of a -adrenoceptors in the endothelium-dependent depression of noradrenaline-induced contraction in rat aorta. Eur J Pharmacol 1993;240: 195- 200.
World Medical Association Declaration of Helsinki. Recommendations guiding physicians in biomedical research involving human subjects. JAMA 1997; 277: 925–6.
Van Rossum JM. Cumulative dose-response curves II. Technique for the making of dose response curves in isolated organs and the evaluation of drug parameters. Arch Int PharmacodynTher 1963; 143: 291–330.
Shimokawa H, Flavahan NA, Lorenz RR, Vanhoutt PM. Prostacyclin releases endothelium-derived relaxing factor and potentiates its action in coronary arteries of the pig. Br J Pharmacol 1988;95: 1197–203.
Fulton RM, Hutchinson EC, Jones AM. Ventricular weight in cardiac hypertrophy. Br J Card 1952;14: 413–20.
Roberts JC, Smith RE. Time-dependent responses of brown fat in cold-exposured rats. Am J Physiol 1967;22: 519–25.
Ames RP, Brokowski AJ, Sicinski MAM, Laragh JH. Prolonged infusions of angiotensin II and norepinephrine and blood pressure, electrolyte balance and aldosterone and cortisol secretion in normal man and in cirrhosis with ascites. J Clin Invest 1965;44: 1171–86.
Jennings GL, Nelson L, Esler MD, Leonard P, Korner PI. Effects of changes in physical activity on blood pressure and sympathetic tone. J Hypertens 1984;2: 139–41.
Angus JA, Cocks TM, Satoh K. α-adrenoceptors and endothelium-dependent relaxation in canine large arteries. Br J Pharmacol 1986;88: 767–77.
Cocks TM, Angus JA. Endothelium-dependent relaxation of coronary arteries by noradrenaline and serotonin. Nature 1983;305: 627–30.
Yanagisawa T, Kameda M Taira N. Nitroglycerin relaxes canine coronary arterial smooth muscle without reducing intracellular Ca2+ concentrations measured with fura-2. Br J Pharmacol 1989;98: 469–82.
Hiraoka M, Yamagishi S, Sano T. Role of calcium ions in the contraction of vascular smooth muscle. Am J Physiol 1968;214: 1084–9.
Furchgott RF. The role of endothelium in the responses of vascular smooth muscle to drugs. Ann Rev Pharmacol Toxicol 1984;24: 175–97.
Bernstein RD, Ockoa FY, Xu X, et al. Function and production of nitric oxide in the coronary circulation of the conscious dog during exercise. Circ Res 1996;79: 840–8.
Nadaud S, Philippe M, Arnal JF, Michel JB, Soubrier F. Sustained increase in aortic endothelial nitric oxide synthase expression in vivo in a model of chronic high blood flow. Circ Res 1996;79, 857–63.
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Kashimura, O. Increase of norepinephrine-induced endothelium-dependent relaxation of pulmonary artery in rats after chronic exposure to cold. Environ Health Prev Med 3, 197–201 (1999). https://doi.org/10.1007/BF02932258
Received:
Accepted:
Issue Date:
DOI: https://doi.org/10.1007/BF02932258