[Synthesis and biological activity of an analogue of active fragment (SP-6) of substance P].
SP-6 was synthesized by solid phase method in 95% purity on HPLC. The data obtained from amino acid analysis and fast atom bombardment were in good agreement with theoretical values. Intravenous injection of SP-6 in rabbits at the dosage of 14.3 micrograms/kg. resulted in blood pressure reduction of 4.4 kPa, i.e. 34% (P < 0.001). When the concentration of SP-6 in Tyrode solution was 5.2 x 10(-4) mg/ml the contraction of rabbit duodenum longitudinal muscle increased by 105%. (P < 0.001). When the concentration was more than 1 x 10(-3) mg/ml, the contractile effect was restrained significantly. Dropping 30 microliters of SP-6 (1 x 10(-3) mg/ml) to toad intestinum tenue mesenteriale in situ, the mesentery arterioles were expanded by 30%.
Department of Biology, Lanzhou University.
G L
GL
Yang
R D
RD
Li
Z Y
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Wang
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Hu
D000818:Animals; D001794:Blood Pressure / Q000187:drug effects*; D002023:Bufo bufo; D004386:Duodenum / Q000187:drug effects; D005260:Female; D008297:Male; D008638:Mesenteric Arteries / Q000502:physiology; D009119:Muscle Contraction / Q000187:drug effects*; D009130:Muscle, Smooth / Q000187:drug effects; D009842:Oligopeptides / Q000138:chemical synthesis / Q000494:pharmacology*; D011817:Rabbits; D014664:Vasodilation / Q000187:drug effects*
D009842:Oligopeptides; C047909:arginyl-threonyl-prolyl-prolyl-prolyl-seryl-glycine