Tachykinin-induced anion secretion in guinea pig distal colon: role of neural and inflammatory mediators.
The effects of substance P and related tachykinins on short-circuit current were determined in submucosa-mucosa sheets of guinea pig distal colon. Substance P, neurokinin A, eledoisin and physalaemin evoked a concentration-dependent increase in short-circuit current with a rank order of potencies of substance P = physalaemin greater than eledoisin = neurokinin A. The substance P response was reduced in chloride-free solutions or after addition of furosemide. Tetrodotoxin, atropine, mecamylamine and pyrilamine reduced the response to substance P. The substance P antagonist, [D-Arg1,D-Phe5,Trp7,9,Leu11]-substance P, reduced the response to neural stimulation and to exogenous substance P. The results suggest that substance P evokes anion secretion by activating cholinergic and noncholinergic neurons and by releasing histamine.
Kuwahara
A
A
Department of Physiology, Ohio State University, Columbus.
Cooke
H J
HJ
D000818:Animals; D001285:Atropine / Q000494:pharmacology; D002712:Chlorides / Q000378:metabolism; D003106:Colon / Q000187:drug effects / Q000378:metabolism*; D004305:Dose-Response Relationship, Drug; D004558:Electric Stimulation; D005665:Furosemide / Q000494:pharmacology; D006168:Guinea Pigs; D006636:Histamine Release / Q000187:drug effects; D066298:In Vitro Techniques; D008297:Male; D011738:Pyrilamine / Q000494:pharmacology; D013373:Substance P / Q000494:pharmacology / Q000502:physiology*; D015320:Tachykinins / Q000494:pharmacology / Q000502:physiology*; D013779:Tetrodotoxin / Q000494:pharmacology
D002712:Chlorides; D015320:Tachykinins; D013373:Substance P; D013779:Tetrodotoxin; D001285:Atropine; D005665:Furosemide; D011738:Pyrilamine