Immunohistochemical investigation of the pituitary of the sturgeon (Acipenser baeri, Chondrostei)

Abstract

An immunohistochemical study of the sturgeon (Acipenser baeri) pituitary was undertaken using antisera directed against hormones from various classes of vertebrates, including the only pituitary hormone available from sturgeon, gonadotrophin. A positive reaction was obtained after application of antisera towards the following hormones 1-24 synthetic ACTH (1-24 ACTH), melanophore stimulating hormone (MSH), ovine prolactin (oPRL), ovine growth hormone (oGH), salmon growth hormone (sGH), carp gonadotrophin (cGTH) and its beta subunit (βcGTH), sturgeon gonadotrophin (aciGTH), carp thyrotrophin (cTSH) and β subunit of the human thyrotrophin (βhTSH). The results demonstrate that, in general, the sturgeon pituitary resembles that of teleosts as regards the distribution of the different cell types: ACTH and PRL cells in the rostral pars distalis, GTH, TSH and GH cells in the proximal pars distalis and MSH and PAS-cells in pars intermedia. In addition to the topographical organization of the sturgeon pituitary, this study provides data on the immunological relationships between sturgeon pituitary hormones and those of other vertebrates.

Early development of the pituitary gland in Acipenser naccarii (Chondrostei, Acipenseriformes): an immunocytochemical study

“…In 160-day-old juveniles they are observed in PI region around the neurohypophysis branches and, in large numbers, within RPD follicle walls. The ir-MSH cells were not detected in the RPD in adults of A. baeri (Pelissero et al 1988) and A. transmontanus (Joss et al 1990A), suggesting that their presence in follicle walls is restricted to juvenile stages. A switch from a-MSH to ACTH production by the pars distalis cells is also observed in mammals and amphibians reaching sexual maturity (Dores et al 1989).…”

“…In A. naccarii we used the human ACTH (1-24) antiserum, largely used to detect ir-ACTH cells in several teleosts (Follenius and Dubois 1980;Batten 1986;CambrØ et al 1986;García-Hernµndez et al 1996;Vissio et al 1997), although unable to identify the ir-MSH ones. The combined use of human ACTH and a-MSH antisera allows a clear identification of the two cell types during A. naccarii development, as previously obtained in adult A. baeri and A. transmontanus (Pelissero et al 1988;Joss et al 1990A) and in teleosts (Batten 1986;CambrØ et al 1986;García-Hernµndez et al 1996;Villaplana et al 2002;Grandi et al 2003).…”

“…For this study we successfully used chum salmon PRL antiserum. The ir-PRL cells were identified by ovine PRL antiserum in A. gueldenstaedti adults (Hansen and Hansen 1975) and in A. baeri adults (Pelissero et al 1988): salmon PRL antiserum was unsuccessful in A. baeri (Pelissero et al 1988). In teleosts, PRL plays an osmoregulatory role during the life cycle of freshwater and brackish water species and in adults of euryhaline ones (Mancera et al 1993, Manzon 2002, and may be also connected to larval growth and differentiation (Majumdar and Elsholtz 1994;Saga et al 1999).…”

“…The distribution of the pituitary endocrine cells was studied by immunocytochemical techniques in adults of the Russian sturgeon, A. gueldenstaedti, by Hansen, (1971) and Hansen and Hansen (1975), of the Siberian sturgeon, A. baeri, by Pelissero et al (1988) and of the white sturgeon, A. transmontanus, by Joss et al (1990A) and Amemiya (1999). Overall, in the adenohypophysis of sturgeon species seven types of endocrine cells were identified: the adrenocorticotrophic (ACTH) and prolactin (PRL) cells in RPD, the growth hormone (GH), gonadotropic (GtH) and thyroid stimulating hormone (TSH) cells in PPD, the melanocyte stimulating hormone (MSH) and somatolactin (SL) cells in PI.…”

Immunocytochemical identification of adenohypophyseal cells in the pirarucu (Arapaima gigas), an Amazonian basal teleost

“…Some of these studies have focussed on species of ancient fish groups, including: (1) species of the oldest class of vertebrates, Agnatha (jawless fish), such as lampreys and hagfish (Nozaki et al 2001(Nozaki et al , 2005Kawauchi et al 2002); (2) representative species of Actinopterygii (subclasses Chondrostei and Neopterygii), such as the Acipenser sp. (Grandi and Chicca 2004;Hansen and Hansen 1975;Joss et al 1990a;Pelissero et al 1988), Lepisosteus sp., and Amia sp. (Joss et al 1990a); and (3) some ancient representatives of the teleost group, such as the eel Anguilla sp.…”