Fusobacterium necrophorum haemolysin stimulates motility of ileal longitudinal smooth muscle of the guinea-pig.
Fusobacterium necrophorum haemolysin (0.5-3.1 mg protein/mL) dose-dependently induced contractions of the isolated ileal longitudinal smooth muscle of the guinea-pig. The haemolysin (3.1 mg protein/mL) -induced maximum contraction of 75% of the response to 60 mM K+ declined within 17 min and the muscles then demonstrated rhythmic contractions. Tetrodotoxin (3.1 x 10(-6) M) had no effect on the contraction due to the haemolysin. After incubation in Ca(2+)-free medium, the ileal response to the haemolysin was lost. Verapamil, a Ca2+ channel blocker, dose-dependently inhibited the contraction to the haemolysin. The rabbit anti-serum against F. necrophorum haemolysin inhibited the haemolysin-induced contraction of ileal muscle. The bacterial haemagglutinin and the lipopolysaccharide had no effect on the response of ileal muscle. These findings suggest that the haemolysin-induced direct stimulation of ileal motility dependant on Ca2+ influx will increase the probability of contact of F. necrophorum and ileal mucosa and could increase the chances of colonization for F. necrophorum.
Kanoe
M
M
Laboratory of Animal Science, Tokyo University of Agriculture, Japan.
Toyoda
Y
Y
Shibata
H
H
Nasu
T
T
D000818:Animals; D002118:Calcium / Q000494:pharmacology; D002121:Calcium Channel Blockers / Q000494:pharmacology; D002417:Cattle; D004305:Dose-Response Relationship, Drug; D005675:Fusobacterium necrophorum / Q000737:chemistry*; D006168:Guinea Pigs; D006460:Hemolysin Proteins / Q000276:immunology / Q000494:pharmacology*; D007082:Ileum / Q000187:drug effects* / Q000502:physiology; D007106:Immune Sera / Q000494:pharmacology; D066298:In Vitro Techniques; D008297:Male; D009119:Muscle Contraction / Q000187:drug effects*; D009130:Muscle, Smooth / Q000187:drug effects* / Q000502:physiology; D011817:Rabbits; D014700:Verapamil / Q000494:pharmacology
D002121:Calcium Channel Blockers; D006460:Hemolysin Proteins; D007106:Immune Sera; D014700:Verapamil; D002118:Calcium