Pituitary cytology of the Indian carp Labeo rohita (Ham.)

In the adenohypophysis of Labeo rohita eight cell types could be identified on the basis of their different tinctorial response to various staining techniques. The rostral pars distalis has 3 types of cells. Type 1 is stained with erythrosin, orange G, and acid fuchsin. Type 2 cells are lead hematoxylin positive and give an amphiphilic reaction in response to tri and tetrachrome techniques. Type 3 cells are stainable with PAS, ATh, AB, AF, and aniline blue and are distributed in an area comprises of anteroventral RPD and anterodorsal PPD. Apart from type 3, the PPD has two more cell types. The classical acidophils forming the type 4 cells readily take up orange G, erythrosin and acid fuchsin. Type 5 cells have affinity for PAS, ATh, AB, AF and aniline blue as that of type 3 cells, but they are relatively smaller. Pars intermedia has type 6 and 7 cells which are PbH and lightly PAS + ve respectively. Eight cell type is constituted by the chromophobes which are seen in all the components of the adenohypophysis, they might be the immature or degranulated chromophils. On the basis of colour reactions cell types 1, 2, 3, 4 and 5 of Labeo rohita are comparable to the prolactin, ACTH, TSH, STH and gonadotropin secreting cells described in other teleosts by earlier workers using comparable techniques. However, functional interpretation based on staining reactions is tentative and needs experimental verification.