Some Effects of Chronic Stimulation on the Rat Carotid Body
The mammalian carotid body is stimulated when the blood-oxygen tension or pH is lowered. Elevation of the arterial partial pressure of carbon dioxide also causes stimulation. It is well known that chronic stimulation of the carotid body by placing an animal in an environment where the inspired oxygen levels are maintained low artificially results in enlargement of the carotid body (1). There is, however, some argument about the mechanism of the enlargement. Thus some workers maintain that it is a result of hypertrophy of the cellular and vascular components (2) whilst others believe that, in addition to hypertrophy, there is also hyperplasia of at least some tissue within the carotid body (3). Here we report experiments that demonstrate that hyperplasia of cellular elements within the rat carotid body is an important part of the response to chronic hypoxia.
KeywordsPlacebo Depression Dopamine Epoxy Noradrenaline
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