Involvement of septide-sensitive tachykinin receptors in inositol phospholipid hydrolysis in the rat urinary bladder.
The selective NK2 agonist [Lys5-MeLeu9,Nle10]NKA(4-10) markedly stimulated [3H]inositol monophosphate (PI1) formation in prisms from the rat urinary bladder. This response was blocked by the NK2 antagonist SR 48968. Senktide (NK3 agonist) was inactive. Septide, a short SP analogue, and the NK1 agonists [Pro9]SP and [Sar9,Met(O2)11]SP also stimulated [3H]IP1 formation and several NK1 tachykinin antagonists (RP 67580, CP 96345, GR 82334, and [D-Pro9,t beta-BPr10,Trp11]SP) were more potent in blocking the septide than the [Pro9]SP response. GR 82334 was the most discriminative. SR 48968 (10(-6) M shifted the [Pro9]SP dose-response curve but did not modify the septide dose-response curve. Septide had a low affinity for [3H][Pro9]SP binding sites, suggesting further that septide and NK1 agonists act on different receptors. Finally, both [Pro9]SP and [Sar9,Met(O2)11]SP blocked the septide-evoked response, acting as partial agonists at the septide-sensitive tachykinin receptors.
D000595:Amino Acid Sequence; D000818:Animals; D001549:Benzamides / Q000494:pharmacology; D006868:Hydrolysis; D007211:Indoles / Q000494:pharmacology; D054833:Isoindoles; D008297:Male; D008969:Molecular Sequence Data; D009119:Muscle Contraction / Q000187:drug effects; D009130:Muscle, Smooth / Q000187:drug effects; D015288:Neurokinin A / Q000031:analogs & derivatives / Q000494:pharmacology; D010446:Peptide Fragments / Q000494:pharmacology*; D010716:Phosphatidylinositols / Q000378:metabolism*; D010880:Piperidines / Q000494:pharmacology; D011761:Pyrrolidonecarboxylic Acid / Q000031:analogs & derivatives; D051381:Rats; D017207:Rats, Sprague-Dawley; D018039:Receptors, Tachykinin / Q000187:drug effects*; D013373:Substance P / Q000031:analogs & derivatives* / Q000494:pharmacology; D001743:Urinary Bladder / Q000187:drug effects
D001549:Benzamides; D007211:Indoles; D054833:Isoindoles; D010446:Peptide Fragments; D010716:Phosphatidylinositols; D010880:Piperidines; D018039:Receptors, Tachykinin; C083383:neurokinin A (4-10), Lys(5)-MeLeu(9)-Nle(10)-; C067285:substance P, Pro(9)-; C062618:substance P, Sar(9)-Met(O2)(11)-; C071693:7,7-diphenyl-2-(1-imino-2-(2-methoxyphenyl)ethyl)perhydroisoindol-4-one; D013373:Substance P; C073839:SR 48968; C054725:septide; D015288:Neurokinin A; D011761:Pyrrolidonecarboxylic Acid