Article révisé par les pairs
Résumé : After fixation in Helly's fluid, beta cells of the human hypophysis and the corresponding cells of swine pituitary are selectively stained by methazol blue and display a bluish black color. Postchroming of the sections enhanced the staining. This observation allows one to question the glycoproteic nature of the granules characteristic of the beta cells. However, this classical assumption relies only on the fact that the beta cells, and their homologues in the animal, are strongly PAS reactive. It should be noted that, in addition to glycoproteins, PAS also reacts with lipids and lipoproteins. Hence, the affinity of the beta cell granules for methazol blue may suggest that their reaction with PAS might be due to their lipoproteic content. The cytoimmunological approach by means of a immune serum anti ACTH 17 39 has confirmed that in man, only the beta cells are stained by methazol blue, which are indeed responsible for the secretion of corticotrophin. However, in the swine, the affinity of the beta cells for methazol blue is less specific since, in addition to all corticotrophic cells, secretory granules of the LH cells are also colored by this stain.