Inhibition of tryptase release from human colon mast cells by protease inhibitors

Table 1 Spontaneous and anti-IgE or calcium ionophore in-duced tryptase release from human colon mast cells

Compound		Tryptase released (ng/mL)
		15 min	35 min
Buffer alone		22.4 ± 3.2	20.5 ± 2.8
Anti-IgE	10 μg/mL	41.6 ± 4.3a	37.6 ± 2.6a
CI	1.0 μg/mL	38.8 ± 3.0a	38.4 ± 3.6a

The values shown are mean ± SEM for six separate experiments.

^aP < 0.05 compared with buffer alone control (Student’s t test).

Table 2 Effect of protamine on anti-IgE or calcium ionophore (CI) induced tryptase release from human colon mast cells

Protamine concentration(μg/mL)	% inhibition of tryptase release
	No preincubation		20 min preincubation
	Anti-IgE	CI	Anti-IgE	CI
0.1	4.0 ± 2.3	5.1 ± 4.5	nd	nd
1.0	17.3 ± 5.2	16.7 ± 4.6	21.4 ± 3.8a	19.5 ± 2.9a
10	20.9 ± 4.3a	17.1 ± 3.8	-0.7 ± 1.8	-9.7 ± 11
100	-54.7 ± 13b	-24.9 ± 8.9b	nd	nd

The values shown are mean ± SEM for six separate experiments. Protamine was either added to cells at the same time with anti-IgE or CI, or preincubated with cells for 20 min before challenged with anti-IgE or CI.

^alevels of tryptase reduced in comparison with the uninhibited control (P < 0.05, Student’s t test).

^blevels of tryptase elevated in comparison with the uninhibited con-trol (P < 0.05, Student’s t test). nd = not done.