Experimental demonstration of the cell types in the adenohypophysis of the gobiid fish, Rhinogobius brunneus.

The hypophysis of the common freshwater goby, Rhinogobius brunneus, accompanying gonadal maturation, was studied light microscopically to determine the cell types by the aid of the administration of antithyroidal and antiadrenocortical drugs. It is peculiar in that the hypophysis is entirely buried in the hypothalamus, and that the entire adenohypophysis is covered with a thin layer of the neurohypophysis. Two types of cells, azocarminophil prolactin cells and PbH-positive adrenocorticotrophs, are discernible in the rostral pars distalis. The proximal pars distalis consists of three types of cells: weakly AF positive thyrotrophs, strongly AF positive gonadotrophs and orangenophil somatotrophs. In spite of the application of several stainings, only one cell type, the PbH-positive cell, is demonstrated in the pars intermedia.