THE ADENOHYPOPHYSIS OF MEDITERRANEAN YELLOWTAIL, SERIOLA-DUMERILII (RISSO, 1810) - AN IMMUNOCYTOCHEMICAL STUDY

The adenohypophysis (ADH) of the Mediterranean yellowtail was studied using the peroxidase-antiperoxidase technique. Human corticotropin (AC TH) (1-24)-immunoreactive (ir) cells were found bordering the neurohyp ophysis (NH) and salmon prolactin (PRL)-ir cells were arranged in thic k cords, both in the rostral pars distalis (RPD). Gonadotropin (GTH)-, thyrotropin (TSH)- and growth hormone (GH)-ir cells were observed in the proximal pars distalis (PPD). Anti-chum salmon GTH I and anti-chum salmon GTH II immunostained the same cells in the outermost part of t he ADH at the level of the PPD and the PI. In addition to these cells, some cells grouped in the inner areas of the posterior PPD were revea led by catfish alpha,beta-GTH antiserum. Human beta-TSH-ir cells forme d small groups and discontinuous strands in the PPD often in contact w ith the NH. Tilapia GH-ir cells formed cords mainly surrounding the NH in the central PPD, while cod somatolactin- and alpha MSH-ir cells ma inly surrounded the NH branches in the PI.