Effect of cold exposure of the rabbit on the subsequent performance of its isolated ear artery with respect to temperature
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New Zealand white rabbits were exposed to an environmental temperature of either 20°C (control) or 5°C (cold-exposure) for periods of from one to six weeks. Ear skin temperature was around 30°C in the control environment and fell to around 15°C in the cold environment. Compared with control arteries, ear arteries from cold-exposed animals tended to have a lower optimal temperature for responses to injected noradrenaline (NOR). At 37°C, responses of control arteries exceeded those of cold-exposed arteries; at 12°C the situation was reversed. A similar “cross-over” effect was observed with responses to electrical stimulation (ES). However, in both groups of arteries, responses to ES were better preserved than were responses to NOR at low temperatures, possibly because cooling interfered with uptake into neuronal stores of NOR released by ES, thus allowing more NOR to reach the arterial muscle at these low temperatures.
KeywordsElectrical Stimulation Cold Exposure Zealand White Rabbit IRISH Journal Arterial Muscle
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- Bazett, H. C., Love, L., Newton, M., Eisenberg, L., Day, R. and Forster, R. 1948. Temperature changes in blood flowing in arteries and veins in man. J. appl. Physiol., 1, 3.Google Scholar
- de la Lande, I. S., Frewin, D. and Waterson, J. G. 1967. The influence of sympathetic innervation on vascular sensitivity to noradrenaline. Br. J. Pharmac. Chemother., 31, 82.Google Scholar
- Glover, W. E., Strangeways, D. H. and Wallace, W. F. M. 1968. Responses of isolated ear and femoral arteries of the rabbit to cooling and to some vasoactive drugs. J. Physiol., 194, 78P.Google Scholar
- Herron, A., Mock, G. R. and Wallace, W. F. M. 1971. Evidence for a non-specific sensitizing action of physostigmine (eserine) on constrictor responses of smooth muscle in the rabbit ear artery. J. Physiol., 216, 61P.Google Scholar
- Joyce, C. M. 1967. The effect of environmental temperature on succinic dehydrogenase activity in the ear skin of the rabbit. Proc. R. Ir. Acad., 65, B, 425.Google Scholar
- McClelland, R. J., McGrann, S. and Wallace, W. F. M. 1969. Evidence that the responses of the perfused rabbit ear artery are influenced by the environmental conditions of the animal. J. Physiol., 205, 5P.Google Scholar
- Martin, R. P. and Wallace, W. F. M. 1970. The effect of temperature on the response of the perfused rabbit ear artery to electrical stimulation. J. Physiol., 207, 80P.Google Scholar
- Paton, W. D. M. 1955. The response of the guinea-pig ileum to electrical stimulation by coaxial electrodes. J. Physiol., 127, 40P.Google Scholar