THE ADENOHYPOPHYSIS OF THE SWAMP EEL, SYNBRANCHUS-MARMORATUS, AN IMMUNOCYTOCHEMICAL ANALYSIS

The adenohypophyseal cell types of the protogynous fish Synbranchus ma rmoratus were studied by histochemical and immunocytochemical staining with antisera raised against piscine and human pituitary hormones to ascertain their distribution. The prolactin (PRL) cells were distribut ed in the rostral pars distalis and showed specific binding to antiser a to carp and chum salmon prolactin. No reaction was observed with ant iserum to human prolactin. The corticotrops showed strong immunoreacti vity with anti-human ACTH, these cells bordered the neurohypophysis an d islets between PRL, cells in the rostral pars distalis. Growth hormo ne (GH) cells were densely distributed and associated with the neurohy pophysis only in pars distalis proximal. They reacted with antisera to piscine GH but not with antisera to human growth hormone. The thyrotr ops were scattered in the proximal pars distalis and showed strong imm unoreactivity to the human thyrotropin Beta subunit antiserum. Gonadot rops were located in the central area of the proximal pars distalis an d in the external border of the pars intermedia. These cells were alci an blue and PAS positive, and reacted with anti-croaker GTH and anti-c oho GTH I and GTH II. The PAS positive cells from the pars intermedia bound specifically to anti-chum somatolactin.