Effects of Hypoxia and Glucocorticoids on the Histochemically Demonstrable Catecholamines of the Newborn Rat Carotid Body

The histochemically demonstrable catecholamines of newborn rat carotid bodies were studied using the formaldehyde induced fluorescence (FIF) method. The effects of both heavy anoxia and repeated injections by glucocorticoids were registered. The newborn rat carotid body consisted of bright yellow fluorescing cells. During the following 2 weeks the intensity of this fluorescence decreased distinctly while fluorescent network of adrenergic nerve fibres developed. The fluorescent nerves were in close contact with the chief cells of the carotid body. Hydro‐cortisone or prednisolone treatment prevented the loss of fluorescence normally occurring. Anoxia caused a marked decrease in the FIF in the majority of glomus cells in 9—16 day old rats.