A Comparative Study on the Distribution of Medullary (Chromaffin) Cells in the Vertebrate Adrenal Glands

抄録

A comparative and comprehensive report is given on the distribution of chromaffin and nonchromaffin cells in the lower vertebrates by means of iodate and chromaffin tests. Whatever be the distribution of these two types of cells, there is a gradual tendency for a close proximity between adrenaline cells from the chromaffin tissue and the nonchromaffin cells. This seems to support the claim that the nonchromaffin cells provide glucocorticoids to the adrenaline synthesizing mechanism in adrenaline cells. The increase and decrease respectively in adrenaline and noradrenaline from fishes to mammals is supported by the corresponding increase and decrease in adrenaline and noradrenaline cells. The possible evolutionary implications of these findings are discussed.