LOCALIZATION OF CONNEXIN43 IN RAT-KIDNEY

The localization of connexin43 (Cx 43) in rat kidney was investigated by the indirect immunofluorescence technique with polyclonal antisera raised against Cx 43. Cx 43 is a gap junction protein expressed in a v ariety of tissues. The typically punctuated gap junction immunofluores cence (GJI) was observed in the renal arterial and arteriolar system. In the renal artery the GJI was concentrated in the media. In the juxt amedullary nephrons, the GJI is particularly abundant in the vascular bundles. There is abundant GJI in the extraglomerular mesangium while in the afferent arteriole GJI appears decreased. Abundant GJI was obse rved in the inner medullary collecting ducts and pelvic epithelium. Th e localization of Cx 43 immunofluorescence observed in this study is o nly in partial agreement with the results of ultrastructural investiga tions on the distribution of gap junctions in the kidney. An extensive tight junctional system has been demonstrated in the collecting duct system. However, gap junctions have been reported to be absent. Furthe r studies to resolve this discrepancy are required.