title: Somatostatin receptors type 2 and 5 expression and localization during human pituitary development.
abstract: Somatostatin (SRIF), by acting mainly through sst2 and sst5 receptors, is a potent inhibitor of hormonal secretion by the human anterior pituitary gland. However, the pattern of protein expression of these SRIF receptors remains unknown during pituitary development. To get further insights into the physiological role of SRIF receptors in human development and pituitary function, the present study examined the developmental expression of the sst2 and sst5 receptors in the individual cell types of the anterior human pituitary. Thirteen fetal human pituitaries were investigated between 13 to 38 weeks of gestation (WG) by double-labeling immunofluorescence with antibodies raised against sst2 or sst5 receptors and GH, LH, FSH, TSH, or pro-opiomelanocortin proteins. SRIF immunoreactivity in the hypothalamus and median eminence was investigated at the same developmental ages. Immunoreactivity for the sst2 receptor was evident as early as 13 to 15 WG and onward mainly in TSH-, LH-, and FSH-expressing cells, whereas sst5 immunoreactivity was apparent at the late development stages (35-38 WG). GH-expressing cells mainly expressed sst5 immunoreactivity. SRIF-positive fibers and cells were detected as soon as 13 to 16 WG in the hypothalamus and median eminence and their densities increased with gestational age. The early appearance of hypothalamic SRIF cells and fibers suggests a physiological link between SRIF and its receptors during pituitary development. Whereas sst2 receptors might play a primary role in the differentiation and regulation of TSH, LH, and FSH cells, sst5 receptors appear to be mainly involved in GH regulation from birth onward.
authors.affiliation: Medical Research Council Centre for Synaptic Plasticity (S.P.), University of Bristol, School of Physiology and Pharmacology, Bristol BS8 1TD, United Kingdom; Inserm (S.P., F.G., Z.C., S.J., A.F., L.S., N.d.R., P.G., S.A., P.D.), U676, 75019 Paris, France; University Paris Diderot (S.P., F.G., Z.C., S.J., A.F., L.S., N.d.R., P.G., S.A., P.D.), Sorbonne Paris Cité, UMR676, 75019 Paris, France; and Institute of Pharmacology and Toxicology (S.S.), Jena University Hospital, Friedrich Schiller University Jena, Germany.
authors.forename: Stéphane
authors.initials: S
authors.lastname: Peineau
authors.forename: Fabien
authors.initials: F
authors.lastname: Guimiot
authors.forename: Zsolt
authors.initials: Z
authors.lastname: Csaba
authors.forename: Sandrine
authors.initials: S
authors.lastname: Jacquier
authors.forename: Assia
authors.initials: A
authors.lastname: Fafouri
authors.forename: Leslie
authors.initials: L
authors.lastname: Schwendimann
authors.forename: Nicolas
authors.initials: N
authors.lastname: de Roux
authors.forename: Stefan
authors.initials: S
authors.lastname: Schulz
authors.forename: Pierre
authors.initials: P
authors.lastname: Gressens
authors.forename: Stéphane
authors.initials: S
authors.lastname: Auvin
authors.forename: Pascal
authors.initials: P
authors.lastname: Dournaud
mesh_terms: D002454:Cell Differentiation; D025461:Feedback, Physiological; D005260:Female; D020869:Gene Expression Profiling; D018507:Gene Expression Regulation, Developmental; D005865:Gestational Age; D006801:Humans; D008297:Male; D008856:Microscopy, Fluorescence; D010903:Pituitary Gland, Anterior / Q000196:embryology*; D017481:Receptors, Somatostatin / Q000378:metabolism*; D013997:Time Factors
chemical_list: D017481:Receptors, Somatostatin; C094573:somatostatin receptor 5; C093733:somatostatin receptor 2