Localization of Transforming Growth Factors, TGF beta sub(1) and TGF beta sub(3) , in Hypothalamic Magnocellular Neurones and the Neurohypophysis

• Published in: Journal of neuroendocrinology 2004-07, Vol.16 (7), p.571-576
• Main Authors: Fevre-Montange, M, Dumontel, C, Chevallier, P, Isnard, A K, Guigard, M, Trouillas, J
• Format: Article
• Language: English
• ISSN: 0953-8194; 1365-2826
• DOI: 10.1111/j.1365-2826.2004.01203.x

The distribution of transforming growth factor beta (TGF beta ) in the rat and human hypothalamus and neurohypophysis was investigated by immunocytochemical techniques using rabbit polyclonal antisera against TGF beta sub(1) and TGF beta sub(3). Colocalization of TGF beta sub(1) or TGF beta sub(3) and arginine vasopressin (AVP) in the rat hypothalamus was studied by double immunolabelling in light microscopy, while their subcellular localization in the rat neurohypophysis was investigated by immunoelectron microscopy. TGF beta sub(1) and TGF beta sub(3) immunoreactivity was demonstrated in the cell bodies and processes of neurones in the supraoptic nucleus (SON) and paraventricular nucleus (PVN). The TGF beta -immunoreactive cells were more numerous in the SON compared to the PVN. TGF beta /AVP double-labelled cells were seen in both nuclei, but some neurones in the SON were labelled for TGF beta sub(1) or TGF beta sub(3), although not for AVP. In the rat and human neurohypophysis, TGF beta sub(3) immunolabelling was more diffuse and stronger than TGF beta sub(1) immunolabelling. TGF beta sub(1) expression was seen in axonal vesicles and in neurosecretory granules of the axonal endings, while TGF beta sub(3) was observed in axonal fibres. Colocalization of TGF beta sub(3) or TGF beta sub(1) and AVP was observed in some neurosecretory granules, but many were either single-labelled for TGF beta or AVP or unlabelled. Our results demonstrate, for the first time, the colocalization of TGF beta and neurohypophysial hormones in magnocellular neurones. We suggest that TGF beta secreted by the neurohypophysis regulates the proliferation and secretion of certain anterior pituitary cells.