Effect of endothelin-1, endothelin-3 and C-terminal hexapeptide, endothelin (16-21) on motor activity in rats.
Intracerebroventricular administration of ET-1 (12.5 and 25 pmol/rat) and ET-3 (25 and 50 pmol/rat) induced the loss of the righting reflex and barrel-rolling behaviour in rats. The C-terminal hexapeptide ET(16-21) did not produce these effects. The automated recording of motor activity revealed that, unlike ET (16-21), both ET-1 and ET-3 evoke a dose-regulated increase of the immobility time. Pretreatment with peptidase inhibitors did not modify the activity of subthreshold doses of peptides. Since ET (16-21) display full agonist properties at ETB but does not interact with ETA receptors, the present data suggest that the behavioural syndrome induced by centrally administered ET-1 and ET-3 may be mediated by stimulation of ETA receptors.
Lecci
A
A
Pharmacology Department, A. Menarini Pharmaceuticals, Florence, Italy.
Maggi
C A
CA
Rovero
P
P
Giachetti
A
A
Meli
A
A
D000818:Animals; D004056:Differential Threshold; D004305:Dose-Response Relationship, Drug; D016232:Endothelins / Q000494:pharmacology*; D008297:Male; D009043:Motor Activity / Q000187:drug effects*; D010446:Peptide Fragments / Q000494:pharmacology*; D011480:Protease Inhibitors / Q000494:pharmacology; D051381:Rats; D011919:Rats, Inbred Strains; D013997:Time Factors
D016232:Endothelins; D010446:Peptide Fragments; D011480:Protease Inhibitors; C061533:endothelin (16-21)