[Reaction of the endocrine apparatus of the stomach to thyroxine administration].

Histochemical and electron microscopy identification revealed five types of endocrine cells (A-like, ECL, G, D, EC) in the gastric fundal and pyloric mucosa. Quantitative positive correlation was found between the revealed ECL, G cells and HCl secretion after the 10-day L-thyroxin administration. The correlation became negative after a longer administration. The ultrastructural changes of A-like ECL and G-cells (L-thyroxin for 10 days) proved their increased functional activity. After a longer period of L-thyroxin administration the ultrastructural characteristics of EC, D-cells suggested their degranulation. The majority of A-like, ECL and G-cells existed in the storing phase due to blocking of the extrusion phase.