Neurokinin receptors could be differentiated by their capacity to respond to the transglutaminase-synthesized gamma-(glutamyl5)spermine derivative of substance P.
Four different gamma-(glutamyl5)amine derivatives of substance P (SP) were synthesized in vitro in the presence of purified guinea pig liver transglutaminase and Ca2+. The 1,3-diaminopropane, spermidine, spermine (Spm), and monodansylcadaverine adducts of the neuropeptide were purified by HPLC on a reversed-phase column and characterized by fast atom bombardment mass spectrometry. The gamma-(glutamyl5)Spm derivative of SP (Spm-SP) was found to be able, like the parent neuropeptide, to provoke rabbit aorta relaxation, to decrease rat arterial blood pressure, and to inhibit collagen-induced platelet aggregation. Unlike SP, only a weak inflammatory response was observed when Spm-SP was injected in the rat hind limb. All these effects were found to be prevented by N omega-nitro-L-arginine methyl ester, a well-known nitric oxide synthesis inhibitor. In contrast, Spm-SP was completely ineffective in contracting guinea pig ileal segments, thus confirming our preliminary observations indicating that Spm-SP does not evoke SP-like spasmogenic effects on isolated smooth muscle preparations. The specificity of the effects due to the selective introduction of a Spm moiety at the glutamine5 level was demonstrated by the SP agonist pharmacological profile of the other gamma-(glutamyl5)amine derivatives tested. These results suggest that neurokinin receptors could be differentiated by their capacity to respond to Spm-SP.
Esposito
C
C
Department of Biochemistry and Biophysics, University of Naples Federico II, Italy.
Mancuso
F
F
Calignano
A
A
Di Pierro
P
P
Pucci
P
P
Porta
R
R
D000818:Animals; D001011:Aorta / Q000187:drug effects; D001794:Blood Pressure / Q000187:drug effects; D055598:Chemical Phenomena; D002621:Chemistry; D003094:Collagen / Q000494:pharmacology; D006168:Guinea Pigs; D006614:Hindlimb; D007082:Ileum / Q000187:drug effects; D007249:Inflammation / Q000139:chemically induced; D008297:Male; D010974:Platelet Aggregation / Q000187:drug effects; D010975:Platelet Aggregation Inhibitors / Q000494:pharmacology; D011817:Rabbits; D051381:Rats; D018039:Receptors, Tachykinin / Q000145:classification / Q000187:drug effects*; D013373:Substance P / Q000031:analogs & derivatives* / Q000096:biosynthesis / Q000494:pharmacology; D011503:Transglutaminases / Q000378:metabolism; D014664:Vasodilation
D010975:Platelet Aggregation Inhibitors; D018039:Receptors, Tachykinin; C075389:substance P, N-spermine-Gln(5)-; D013373:Substance P; D003094:Collagen; D011503:Transglutaminases