Immunofluorescent tracing of smooth muscle contractile protein antigens in tissues other than smooth muscle.

Abstract

SUMMARY Rabbit antisera wereprepared against sixcontractile proteins ofsmooth muscleactomyosin, actin, myosin, heavy meromyosin, light meromyosin andtropomyosin extracted fromhumanuterus bystandard procedures. Antibodies weresought bydouble-diffusion ingelandbyimmunofluorescence oncryostat sections of rattissue. Alltheantisera except anti-actin gaveprecipitin lines withtheir respective antigens, andall gavespecific fluorescence withsmooth muscle fibres and produced staining ofliver cells intheregion oftheir cell membranes (polygonal pattern). Anti-actin serastained inaddition renal glomeruli, andalso amicrofilamentous network inHeLacells andchick embryofibroblasts. Anti-heavy meromyosin (andless brightly anti-actin) stained thecytoplasm ofbile duct epithelial cells, andtheapical andbasal regions ofintestinal muscosal cells inalinear fashion. Thesepatterns ofstaining between themreproduce therangeofstainingpatterns seenwithhumanserapositive forsmoothmuscle antibody byimmunofluorescence.