title: Vasopressin(4-9) fragment activates V1a-type vasopressin receptor in rat supraoptic neurones.
abstract: The effect of vasopressin fragment 4-9 (AVP(4-9)) was investigated on freshly dissociated rat supraoptic neurones by measuring changes in intracellular calcium concentration ([Ca2+]i) using fura-2 microspectrofluorimetry. In 60% of neurones responding to vasopressin, AVP(4-9) induced a transient rise in [Ca2+]i that was dose-dependent in the concentration range 10 nM to 1 microM AVP(4-9) and strongly decreased in Ca2+-free buffer (84% inhibition). This [Ca2+]i response was completely and reversibly abolished by SR 49059 (1O nM), a specific V1a receptor antagonist, but not by SR 121463A, a specific V2 receptor antagonist. Our results demonstrate the presence of functional receptors activated by AVP(4-9) on vasopressin-sensitive neurones that possess the apparent pharmacological profile of the V1a-type vasopressin receptor.
authors.affiliation: CNRS UPR-9055, Biologie des Neurones Endocrines, Centre de Pharmacologie Endocrinologie, Montpellier, France.
authors.forename: L
authors.initials: L
authors.lastname: Gouzènes
authors.forename: G
authors.initials: G
authors.lastname: Dayanithi
authors.forename: F C
authors.initials: FC
authors.lastname: Moos
mesh_terms: D000818:Animals; D065092:Antidiuretic Hormone Receptor Antagonists; D001127:Arginine Vasopressin / Q000378:metabolism / Q000494:pharmacology*; D002118:Calcium / Q000378:metabolism; D005456:Fluorescent Dyes; D016257:Fura-2; D006727:Hormone Antagonists / Q000494:pharmacology; D066298:In Vitro Techniques; D007211:Indoles / Q000494:pharmacology; D008297:Male; D009025:Morpholines / Q000494:pharmacology; D009474:Neurons / Q000187:drug effects* / Q000378:metabolism; D010446:Peptide Fragments / Q000378:metabolism / Q000494:pharmacology*; D011759:Pyrrolidines / Q000494:pharmacology; D051381:Rats; D017208:Rats, Wistar; D017483:Receptors, Vasopressin / Q000819:agonists / Q000187:drug effects*; D013141:Spiro Compounds / Q000494:pharmacology; D013495:Supraoptic Nucleus / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism
chemical_list: D065092:Antidiuretic Hormone Receptor Antagonists; D005456:Fluorescent Dyes; D006727:Hormone Antagonists; D007211:Indoles; D009025:Morpholines; D010446:Peptide Fragments; D011759:Pyrrolidines; D017483:Receptors, Vasopressin; D013141:Spiro Compounds; D001127:Arginine Vasopressin; C045881:argipressin (4-9); C103281:satavaptan; C082134:relcovaptan; D002118:Calcium; D016257:Fura-2