Introduction: The immunohistochemical description of the pituitary cell types were done in thin-lipped mullet, Liza ramada. Water quality plays a determined role in the activity of the pituitary gland of teleosts. Nevertheless, the immunohistochemistry of the hypophysis in mature L. ramada captivated in different waters was lacked.
Aim of the Work: We designed the present work to examine the environmental salinity effects on the immunohistochemistry of the hypophysis in mature L. ramada.
Material and Methods: Immunoreactivity of the hypophyseal hormone-secreting cells of mature L. ramada, captivated in fresh and saline waters, was investigated by the immunohistochemical technique using specific antibodies raised against hormones from piscine and mammalian origin.
Results: We investigated the immunoreactivities of the growth hormone family- cells (growth hormone; GH-, prolactin hormone; PRL- and somatolactin; SL- secreting cells) as well as the adrenocorticotropic hormone (ACTH) of mature L. ramada in both fresh water (FW) and saline water (SW). Mature brood fishes captivated in saline water exhibit a dramatic decrease in the area and size of GH-, PRL-, SL- and ACTH- immunoreactive (ir) cells in comparison to those of freshwater fishes. Also, the integrated optical density (IOD) of the GH family and the ACTH immunostaining inside the corresponding cells was declined significantly in saline water.
Conclusion: The observed changes in the immunoreactivities of PRL-, SL-, GH- and ACTH-ir cells, in response to increase in the environmental salinity, reinforces the potential role of such hormones in the osmoregulation during mullet aquaculture.