Quantitative studies of rat carotid body type I cells.

The general structure and results of quantitative studies of rat carotid body type I cells are described. In contrast to previous reports, there was no change in mitochondrial V/v% on stimulating the carotid body with 10% oxygen. The volume of cytoplasm occupied by electron-dense cored vesicles was significantly increased, whilst their density per square micrometre of cytoplasm was decreased during hypoxia.

Quantitative studies of the cat carotid body. III. The type I cells.

The work reported here examines the quantitative ultrastructure of cat carotid body type I cells, and the effects of hypoxia on the cells. On the basis of size and density of electron-dense cored vesicle (EDCV) we were unable to identify more than one major population of type I cells. Prior ventilation of the animals with 10% O2 resulted in an increase in the volume percentage (Vv%) of mitochondria and a decrease in the Vv% of EDCV as compared to the values after ventilation with 100% O2.

Catecholamines in the carotid body of several mammalian species: effects of surgical and chemical sympathectomy.

The catecholamine content of the carotid body of several mammalian species has been assayed using high performance liquid chromatography coupled to electrochemical detection and radioenzymatic assays. Although there were strain differences in the content of catecholamines in the carotid body of the rat, noradrenaline was equal to or exceeded the dopamine level in this species. No apparent differences were found in carotid bodies of animals killed by cervical dislocation or those dissected from anaesthetized animals.