Identification of Galanin-Immunoreactive Cells in the Anterior Pituitary of Male Monkeys (Macaca fascicularis).

Abstract

Abstract. The localization of galanin (GAL) was studied in the anterior pituitary of adult male macaque monkeys immunohistochemically.GAL-immunoreactive fiber bundles were noted in the posterior lobe of the pituitary. Cells immunoreactive for GAL were observed in the anterior lobe, and colocalization studies revealed that GAL-like immunoreactivity was present in gonadotrophs and thyrotrophs. The differences among the monkey, human and rat in GAL-immunoreactive localization may indicate that the regulation of GAL in the three species differs. Recently, GAL-LI was observed in the anterior lobe of the pituitary of rats and humans by means of immunohistochemistry [14][15][16][17]. Moreover, GAL mRNA within the anterior lobe of rats has been demonstrated by in situ hybridization [15,16,18]. In the present study, we present our results on the identification of pituitary cell types in the male monkey exhibiting GAL-LI by means of an elution-restaining procedure. Two adult male crab-eating monkeys (Macaca f ascicularis, Clea Japan, Inc., Osaka, Japan) were used for this study. Their body weights at the time of the investigation were 3.2 and 3.9 kilograms. Their ages were approximately 4-5 and 6-7 years, respectively. They were sacrificed by deep pentobarbital anesthesia, and were perfused with 500 ml of saline, followed by 2000 ml of 4% paraformaldehyde in 0.12 M phosphate buffer. The pituitaries were removed, postfixed in the same fixative at 4°C overnight and rinsed in phosphate buffered saline (PBS; pH 7.7) containing 15% sucrose at 4°C for one day. Sagittal and horizontal sections (8 µm) were cut in a cryostat (-20°C), and processed by a previously reported immunofluorescence procedure [10, 11].Anti-porcine GAL serum raised in rabbits was obtained commercially (Peninsula Labs., RAS 7153-N). The antiserum was used at a concentration of 1:400. The slides were incubated overnight with the anti-GAL serum diluted with PBS containing 1 % normal goat serum and 0.1 % sodium azide. They were then rinsed in PBS containing

Neuropeptides in anterior pituitary development

“…Studies on female rats with an altered galanin gene have confirmed that proliferation of lactotrophs under a high dose of oestrogen can be completely abolished (Wynick et al, 1998b), but galanin has also been associated with many other pituitary functions, such as the release of GH or LH, FSH and ACTH in humans. For further reading, we recommend the following references (Vrontakis et al, 1989(Vrontakis et al, , 1996Gabriel et al, 1989Gabriel et al, , 1990Calvo et al, 1990;Hooi et al, 1990aHooi et al, , 1997O'Halloran et al, 1991;Hyde and Howard, 1992;Niimi et al, 1993;Moore et al, 1994;Giustina et al, 1994;Hyde et al, 1996Hyde et al, , 1998Sauer-Ramirez et al, 1996;Hammond et al, 1997;Ceresini et al, 1997;Cai et al, 1998;Todd et al, 1998;Baranowska et al, 1999;Ren et al, 1999;Shen et al, 1999;Zdrojewicz and Sowinska, 2000;Elsaesser, 2001). This is in agreement with the presence of galanin in all pituitary cells during development; they all express galanin which, in the adult, may potentially activate specific functions in specific endocrine cells of the pituitary.…”

Galanin in the regulation of the hypothalamic-pituitary-adrenal axis (Review)

“…Abundant evidence indicates that galanin is expressed in the mammalian anterior pituitary as mRNA and protein (56)(57)(58)(59)(60)(61). In situ hybridization and ICC showed that galanin-positive cells are: i) in female rats predominantly lactotrophs (62)(63)(64)(65), where galanin is co-localized with prolactin in the secretory granules (66); ii) in male rats mainly somatotrophs, thyreotrophs (61) and corticotrophs (65,67); iii) in adult male monkeys thyreotrophs and gonadotrophs (68); and iv) in normal human pituitary and pituitary adenomas almost exclusively corticotrophs (69,70). Galanin-positive nerve fibers were found in the dog, monkey and human anterior pituitary (71,72).…”