Anti-Thy 1–induced albuminuria of rats treated with PBS (control), IVIgG, or IVIgM. Groups of three rats each were injected 500 mg/kg of IVIgG, IVIgM, or 2 mL of PBS, followed after 30 minutes by 0.5 mg/kg ER4G. Urine was collected from 4 to 24 hours after ER4G injection and the albumin content quantitated by rocket electrophoresis. Single determinations for each of the rats were performed, mean values per group and SD are shown. Differences between groups were statistically significant (P < .05) by Student’s t-test.