Barrier Properties of the Intestinal Epithelium in the Dynamics of Nephropathy Progression

The study investigated the effect of 5/6 nephrectomy on the barrier properties of the rats jejunum and colon in the long postoperative period (two, four and six months). It was shown that animals with kidney dysfunction developed progressive azotemia, hypernatremia and hyperkalemia, as well as increased levels of uremic toxins (TMAO and TMA), accompanied by an increase in blood pressure. Two months after nephrectomy, a decrease in short-circuit current and an increase in paracellular permeability were observed in the jejunum, but the transepithelial resistance (TER) did not change. In the colon at this time, an increase in TER and permeability to sodium fluorescein was noted with a decrease in short-circuit current. At the fourth month, the jejunum retained morphological changes in villi and crypts, but the barrier function stabilized due to a compensatory increase in occludin levels with a decrease in claudin-1. Increased permeability remained in the colon without significant changes in the expression of the studied proteins of tight junctions. Six months after nephrectomy, differences in permeability and protein content of tight junctions were leveled compared with the control, although morphological disorders of the epithelium persisted. The results of the study show the potential for restoring the intestinal barrier within six months after the nephrectomy.

kidney, nephrectomy, intestine, intestinal barrier, tight junctions, claudins