Melatonin Receptors on Ovine Pars Tuberalis: Characterization and Autoradiographicai Localization
Open Access
- 1 February 1989
- journal article
- Published by Wiley in Journal of Neuroendocrinology
- Vol. 1 (1) , 1-4
- https://doi.org/10.1111/j.1365-2826.1989.tb00068.x
Abstract
The functional significance of the pars tuberalis (PT) of the mammalian adenohypophysis has remained an enigma (1, 2). One view of its function is that it acts as an auxiliary gland to support the endocrine role of the pars distalis (PD) (2), as it has been shown to contain immunocytochemically identifiable thyrotrophs and gonadotrophs (1). Many of the cells of the PT are, however, ultrastructurally unique suggesting an independent function for this tissue. Our recent demonstration that the PT of the rat is a major binding site for the ligand iodomelatonin lends further support to this idea (3). We have utilized the highly specific ligand [125l]melatonin, and have demonstrated that it binds exclusively, with very high affinity, to the PT but not the PD of the adult sheep adenohypophysis. These findings support the conclusion that the PT has a distinct role in relation to melatonin action and seasonal reproduction.Keywords
This publication has 19 references indexed in Scilit:
- DEMONSTRATION OF MELATONIN-BINDING SITES ON THE PARS TUBERALIS OF THE RATJournal of Endocrinology, 1988
- Iodinated melatonin mimics melatonin action and reveals discrete binding sites in fetal brainFEBS Letters, 1988
- N-(3,5-dinitrophenyl)-5-methoxytryptamine, a novel melatonin antagonist: effects on sexual maturation of the male and female rat and on oestrous cycles of the female ratJournal of Endocrinology, 1988
- Hypothalamic melatonin receptor sites revealed by autoradiographyBrain Research, 1987
- Characterization of central melatonin receptors using 125I‐melatoninFEBS Letters, 1986
- Iodinated melatonin: Preparation and characterization of the molecular structure by mass and 1H NMR spectroscopyAnalytical Biochemistry, 1984
- The mammalian hypophysial pars tuberalis: A comparative immunocytochemical studyGeneral and Comparative Endocrinology, 1984
- Relationship between the inhibition constant (KI) and the concentration of inhibitor which causes 50 per cent inhibition (I50) of an enzymatic reactionBiochemical Pharmacology, 1973
- THE ATTRACTIONS OF PROTEINS FOR SMALL MOLECULES AND IONSAnnals of the New York Academy of Sciences, 1949