Effect of TMB-8 on calcium transport in mast cells in relation to histamine secretion.
We have previously reported an inhibition of histamine release by TMB-8 both in the presence and absence of calcium and with glucose in the medium. In the present investigation we have studied the effect of TMB-8 on calcium transport. The observations show that TMB-8 inhibits calcium uptake and enhances calcium efflux in mast cells. As antigen-induced histamine release from sensitized mast cells is primarily dependent on extracellular calcium, the inhibition of anaphylactic histamine release by TMB-8 is probably mainly due to an inhibition of calcium influx into the mast cells. We have shown an increased calcium efflux during histamine release from mast cells induced by compound 48/80 in the absence of calcium in the medium, suggesting the release of intracellular calcium stores. The increased calcium efflux was not inhibited by TMB-8. On the contrary, the enhanced calcium efflux caused by compound 48/80, was added to that by TMB-8. TMB-8 thus had no effect on the calcium release from intracellular stores by compound 48/80 but the enhanced calcium efflux by TMB-8 would tend to inhibit histamine release.
Chakravarty
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Institute of Pharmacology, Odense University, Denmark.
D000818:Animals; D001693:Biological Transport, Active / Q000187:drug effects; D002118:Calcium / Q000378:metabolism*; D005707:Gallic Acid / Q000031:analogs & derivatives* / Q000494:pharmacology; D006636:Histamine Release / Q000187:drug effects; D066298:In Vitro Techniques; D008297:Male; D008407:Mast Cells / Q000187:drug effects / Q000276:immunology / Q000378:metabolism; D051381:Rats; D011919:Rats, Inbred Strains; D003189:p-Methoxy-N-methylphenethylamine / Q000494:pharmacology
D003189:p-Methoxy-N-methylphenethylamine; C006014:8-(N,N-diethylamino)octyl-3,4,5-trimethoxybenzoate; D005707:Gallic Acid; D002118:Calcium