[Effect of tryptase inhibitors on histamine release from human colon mast cells].
OBJECTIVE
To investigate the effect of tryptase inhibitors (TPIs) on histamine release from human colon mast cells.


METHODS
Human mast cells were prepared by digestion of colon tissue and with collagenase and hyaluronidase, cultured with four kinds of TPIs, leupeptin, protamine, TLCK, and lactoferrin for 15 min at 37 degrees Celsius respectively. A glass fibre-based fluorometry assay was used to detect histamine in mast cell suspension.


RESULTS
200 mmol/L leupeptin and 100 mmol/L protamine were able to stimulate histamine release from colon mast cells, while TLCK and lactoferrin did not. All TPIs inhibited anti-IgE-induced histamine release in a concentration dependent manner, and the inhibitory rates were 48.7%, 36.7%, 40.2% and 34.1%, respectively. However preincubation of TPIs with mast cells for 20 min at 37 degrees Celsius before adding anti-IgE had little effect on anti-IgE induced histamine release. All TPIs were able to inhibit calcium ionophore (CI)-induced histamine release, and the maximum inhibition rate was between 25%-32%. Inhibition on histamine release by leupeptin and TLCK obviously enhanced when colon mast cells were preincubated with them for 20 min before adding CI. However, under the same condition, protamine failed to inhibit histamine release.


CONCLUSIONS
We prove for the first time that TPIs inhibit anti-IgE-and CI-induced histamine release from human colon mast cells, suggesting that it is possible to treat inflammatory bowel disease or other mast cell-related diseases by using TPIs.
Xie
Hua
H
Allergy & Inflammation Research Institute, Medical College of Shantou University, Shantou 515031, China. huaxie823@hotmail.com
He
Shao-heng
SH
Cheng
Ming-hua
MH
Fu
Yi-ling
YL
D002478:Cells, Cultured; D003106:Colon / Q000166:cytology / Q000378:metabolism*; D006636:Histamine Release / Q000187:drug effects*; D006801:Humans; D007781:Lactoferrin / Q000494:pharmacology; D007976:Leupeptins / Q000494:pharmacology; D008407:Mast Cells / Q000187:drug effects / Q000378:metabolism*; D011479:Protamines / Q000494:pharmacology; D011480:Protease Inhibitors / Q000494:pharmacology*; D012697:Serine Endopeptidases / Q000494:pharmacology*; D015842:Serine Proteinase Inhibitors / Q000494:pharmacology; D014107:Tosyllysine Chloromethyl Ketone / Q000494:pharmacology; D053802:Tryptases
D007976:Leupeptins; D011479:Protamines; D011480:Protease Inhibitors; D015842:Serine Proteinase Inhibitors; D014107:Tosyllysine Chloromethyl Ketone; D007781:Lactoferrin; D012697:Serine Endopeptidases; D053802:Tryptases; C032854:leupeptin