Effects of aging on photoperiodic responsiveness and specific 2-[125I]-iodomelatonin binding sites in the pars tuberalis and suprachiasmatic nuclei of Siberian hamsters

1994 ◽  
Vol 16 (4) ◽  
pp. 184-187 ◽  
Author(s):  
Marilyn J. Duncan ◽  
Cheryl C. Purvis
Keyword(s):  
Binding Sites ◽  
Pars Tuberalis ◽  
Suprachiasmatic Nuclei ◽  
Siberian Hamsters ◽  
Effects Of Aging

Daily Rhythms of Melatonin Binding Sites in the Rat Pars tuberalis and Suprachiasmatic Nuclei; Evidence for a Regulation of Melatonin Receptors by Melatonin Itself

1993 ◽  
Vol 57 (1) ◽  
pp. 120-126 ◽  
Author(s):  
François Gauer ◽  
Mireille Masson-Pévet ◽  
Debra Jean Skene ◽  
Berthe Vivien-Roels ◽  
Paul Pévet
Keyword(s):  
Binding Sites ◽  
Melatonin Receptors ◽  
Pars Tuberalis ◽  
Suprachiasmatic Nuclei ◽  
Daily Rhythms

Characterization of Melatonin Binding Sites in the Pars Tuberalis of the European Hamster

1992 ◽  
Vol 4 (2) ◽  
pp. 189-192 ◽  
Author(s):  
D. J. Skene ◽  
M. Masson-Pévet ◽  
P. Pévet
Keyword(s):  
Binding Sites ◽  
Pars Tuberalis

scholarly journals Evidence that melatonin binding sites in the pars tuberalis do not mediate the photoperiodic actions of melatonin on LH and prolactin secretion in ewes

Reproduction ◽  
1994 ◽  
Vol 101 (3) ◽  
pp. 625-632 ◽  
Author(s):  
B. Malpaux ◽  
A. Daveau ◽  
F. Maurice ◽  
A. Locatelli ◽  
J-C. Thiery
Keyword(s):  
Binding Sites ◽  
Prolactin Secretion ◽  
Pars Tuberalis

Daily variations in melatonin receptor density of rat pars tuberalis and suprachiasmatic nuclei are distinctly regulated

1994 ◽  
Vol 641 (1) ◽  
pp. 92-98 ◽  
Author(s):  
François Gauer ◽  
Mireille Masson-Pevet ◽  
Jörg Stehle ◽  
Paul Pevet
Keyword(s):  
Pars Tuberalis ◽  
Receptor Density ◽  
Suprachiasmatic Nuclei ◽  
Melatonin Receptor ◽  
Daily Variations

Characterization of melatonin receptors in the ram pars tuberalis: influence of light

1990 ◽  
Vol 123 (5) ◽  
pp. 557-562 ◽  
Author(s):  
Jean Pelletier ◽  
Bertrand Castro ◽  
Georges Roblot ◽  
Renée Wylde ◽  
Marie-Madeleine de Reviers
Keyword(s):  
Median Eminence ◽  
Binding Sites ◽  
Melatonin Receptors ◽  
Scatchard Analysis ◽  
Pars Tuberalis

Abstract. The present study was conducted to assess the binding of [125I]melatonin to frozen unfixed sections of pars tuberalis/median eminence tissue from Ile-de-France rams exposed or not exposed to light before slaughter. The specificity of [125I]melatonin binding to the pars tuberalis tissue was revealed by autoradiography and the magnitude of binding as related to the pars tuberalis area was determined after incubation and counting of pars tuberalis/median eminence sections. Subsequent studies with sections incubated with [125I]melatonin indicated that 1. the binding sites were saturable; 2. binding was stable for 24 h at 20°C, but unstable at 28 or 37°C; 3. melatonin and [12 7I]melatonin had a similar potency to compete with [125I]melatonin for binding sites, whereas other ligands such as serotonin or N-acetylserotonin were devoid of activity, and 4. by Scatchard analysis, the constant affinity Ka was found to be high in the 1010 l/mol range. Rams exposed to light throughout the night prior to slaughter presented a significant increase in the apparent number of [125I]melatonin binding sites in comparison to animals maintained under darkness (2.25±0.30 vs 1.01±0.17 fmol/mm2 pars tuberalis, p<0.01), whereas Ka values were similar in both groups. These results indicate the presence of true melatonin receptors in the pars tuberalis of the ram. Furthermore, they suggest that their apparent number is light-dependent.

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