Immunohistochemical study of the pars tuberalis of the adenohypophysis in the monkey, Macaca irus.

The pars tuberalis of the hypophysis in the monkey Macaca irus encompasses the hypophysial stem up to the median eminence. Histologically, it consists of several layers of chromophobic cells. A few PAS-positive cells also stainable with Alcian blue (pH 3.0) can be observed among the unstained elements. Using the indirect immunofluorescence antibody technique, scattered immunoreactive cells were revealed with the anti-beta oLH antibody; these cells did not react with the anti-beta hFSH antibody. In contrast, the immunoreactions to anti-hGH, anti-hPRL, anti-ACTH, anti-MSH, anti-LPH and anti-endorphin sera were completely negative. Single cells reacting with the anti-beta hTSH serum were observed at the inferior end of the hypophysial stalk (zona tuberalis), i.e., beyond the pars tuberalis proper. These results are compared with data reported in the literature.