Effects of moderate and intensive training on functional activity of central 5-HT1B receptors in the rat substantia nigra.
The efficacy of the selective 5-HT1B receptor agonist CP 93,129 in inhibiting the forskolin-stimulated adenylyl cyclase activity in the rat substantia nigra was reduced by both moderate and intensive prolonged training compared with sedentary resting rats. The concentration-response curves of the agonist were shifted to the right with a sixfold increase of the half-maximal inhibitory concentration. A difference was observed between the two training exercises in regard to further changes in 5-HT1B receptor sensitivity induced by an acute restraint stress. This manipulation did not affect the functional response of the 5-HT1B receptors further in moderately trained rats, whereas an additional desensitization of the 5-HT1B receptors was observed in intensively trained rats. These results strongly suggest the existence of regulation mechanisms altering the functional efficacy of 5-HT1B receptors and, accordingly, affecting the serotonergic activity, since 5-HT1B receptors modulate the neuronal release of the amine.
Seguin
L
L
Unité de Pharmacologie Neuro-Immuno-Endocrinienne, Institut Pasteur, Paris, France.
Liscia
P
P
Guezennec
Y
Y
Fillion
G
G
D000262:Adenylyl Cyclases / Q000096:biosynthesis; D000818:Animals; D005576:Colforsin / Q000494:pharmacology; D004790:Enzyme Induction; D008297:Male; D010805:Physical Conditioning, Animal / Q000502:physiology*; D011725:Pyridines / Q000494:pharmacology; D011758:Pyrroles / Q000494:pharmacology; D051381:Rats; D017208:Rats, Wistar; D044302:Receptor, Serotonin, 5-HT1B; D011985:Receptors, Serotonin / Q000187:drug effects / Q000502:physiology*; D012149:Restraint, Physical; D017366:Serotonin Receptor Agonists / Q000494:pharmacology; D013378:Substantia Nigra / Q000187:drug effects / Q000201:enzymology / Q000502:physiology*
D011725:Pyridines; D011758:Pyrroles; D044302:Receptor, Serotonin, 5-HT1B; D011985:Receptors, Serotonin; D017366:Serotonin Receptor Agonists; C065046:3-(1,2,5,6-tetrahydropyrid-4-yl)pyrrolo(3,2-b)pyrid-5-one; D005576:Colforsin; D000262:Adenylyl Cyclases