FIG. 8.

Inhibition of the biological activity of STb. STb-mediated secretion was measured in ligated rat small intestinal loops. Each loop received 5 μg of STb diluted in 20 mM Tris-HCl buffer (pH 6.8) containing 300 μg of TI per ml following pretreatment with either laminin (400 μg) or sulfatase (2 U) for 20 min. The standard deviations are shown. Each ratio was significantly different from the STb maximal ratio (0.1 ml/cm), using the statistical Student t test analysis. ∗, P <0.01; ∗∗, P <0.005.