Abstract
Several studies have shown that melanin-concentrating hormone (MCH) is an orexigenic peptide in rat. In the present study, a structure-activity relationship with MCH analogs was performed in rat, both in vitro and in vivo. On rat recombinant SLC-1 receptor, both cAMP inhibition and [125I]S36057 binding were measured. In vivo, these analogs were injected intracerebroventricularly in rats and their effects were evaluated upon food intake. First, data obtained with the rat recombinant receptor were highly correlated with those obtained from its human counterpart. Second, agonist potencies in the cAMP assay were also highly correlated with binding affinities. These peptides could be classified into several groups according to their potency at the SLC-1 receptor (from subnanomolar activity to complete inactivity). Indeed, there was a strong correlation between their effects upon food intake and the results obtained at the rat SLC-1 receptor. The present report describes for the first time the rat SLC-1 receptor pharmacology and clearly establishes the relevance of the SLC-1 receptor in feeding behavior.
Footnotes
-
T.S. was a recipient of a Convention CIFRE between the Association Nationale de la Recherche Technique, the Institut de Recherche SERVIER, and the Center National de la Recherche Scientifique.
- Abbreviations:
- MCH
- melanin-concentrating hormone
- PCR
- polymerase chain reaction
- HEK
- human embryonic kidney
- CSF
- cerebrospinal fluid
- RT-PCR
- reverse transcription-polymerase chain reaction
- ANOVA
- analysis of variance
- Received March 29, 2001.
- Accepted June 4, 2001.
- The American Society for Pharmacology and Experimental Therapeutics
JPET articles become freely available 12 months after publication, and remain freely available for 5 years.Non-open access articles that fall outside this five year window are available only to institutional subscribers and current ASPET members, or through the article purchase feature at the bottom of the page.
|