Fig. 3.

EFS-induced contraction of the rat colonic smooth muscle. SScIgG from a patient in group II (disease duration 420 mo) (B) causes more marked attenuation of EFS response than SScIgG from a patient in group I (disease duration 120 mo) (A) (P < 0.05, n = 4). Attenuation of these EFS responses is reversed by IVIG to values not significantly different from those obtained in the control and IVIG-alone experiments (P > 0.05). C: values of ACh release following EFS (10 V, 5 Hz, 0.5 ms, 30-s train) in the colonic SM strips used for the experiments for SScIgGs from group I vs. group II patients. Data show that EFS causes a significant (P < 0.05, n = 4) increase in ACh release that is mitigated significantly (*P < 0.05, n = 4) by 0 Ca²⁺ and SScIgG. The effects of SScIgG are reversed by IVIG pretreatment to values not significantly different from those obtained in control and IVIG-alone experiments (P > 0.05). NIgG, IgGs from normal subjects.