Anti-stomach serum induces contraction of isolated smooth muscle cells from gastric antrum.
In this work, we investigated the ability of anti-tissue sera to cause contraction of smooth muscle cells (SMC) in vitro. Therefore, we compared the effects of a horse immune serum raised against hog gastric tissue (SER 292), of its globulin fraction (SER 292 globulin), and of its IgG fraction (SER 292 IgG), on concentration of isolated SMC from the gastric antrum of the rabbit. Our results showed that SER 292 IgG induced a dose-dependent contraction of SMC with a higher potency than SER 292 globulin and SER 292. Preincubation of SER 292 globulin with anti-F(ab')2 but not with anti-Fc reduced the contractile activity of this anti-tissue serum. A serum raised against reticulo-endothelial system (SER 108) as well as a non immune serum (SENI) did not show any contractile activity. Our data provide evidence that SER 292 interacts with plasma membrane of SMC through its F(ab')2 fragments. Withdrawal of extracellular Ca2+ caused a significant reduction of the contractile effect induced by SER 292 IgG. When 45 Ca influx was measured, SER 292 IgG induced a specific and significant 45 Ca uptake which was blocked by pinaverium, a 'L-type' calcium channel blocker. These findings tend to show that contraction of SMC induced by SER 292 IgG involves an increase of intracellular Ca2+ concentration due in part to an influx of external Ca2+ via plasma membrane Ca2+ channels sensitive to 'L-type' channel blockers.
Bobo
M H
MH
Laboratoire de Biochimie des Membranes, INSERM CJF 9207, Faculté de Pharmacie, Université de Montpellier, France.
Ammor
S
S
Magous
R
R
Mingard
P
P
Bali
J P
JP
D000818:Animals; D000888:Antibodies, Anti-Idiotypic / Q000276:immunology; D002118:Calcium / Q000378:metabolism; D004306:Dose-Response Relationship, Immunologic; D006736:Horses; D007106:Immune Sera / Q000494:pharmacology*; D007074:Immunoglobulin G / Q000276:immunology; D066298:In Vitro Techniques; D008297:Male; D012157:Mononuclear Phagocyte System / Q000276:immunology; D009119:Muscle Contraction; D009130:Muscle, Smooth / Q000166:cytology / Q000502:physiology*; D011706:Pyloric Antrum / Q000166:cytology / Q000378:metabolism / Q000502:physiology*; D011817:Rabbits; D013270:Stomach / Q000276:immunology*; D013552:Swine
D000888:Antibodies, Anti-Idiotypic; D007106:Immune Sera; D007074:Immunoglobulin G; D002118:Calcium