The origin of proliferating cells in the glomerulus and Bowman's capsule in nephrotoxic serum nephritis: effects of unilateral renal irradiation.

The origin of proliferating cells in glomeruli and Bowman's capsules during nephrotoxic nephritis (NTN) in rabbits was studied, using unilateral renal irradiation to suppress glomerular cell division. Left (LI) kidneys received 2400-12,000 rad on Days 1-5 after i.v. nephrotoxic serum (NTS) 1 or 1.5 ml/kg body wt. Renal histology, cell labelling 1 h after a pulse of tritiated thymidine (H3T) (0.5 mCi/kg), and mitotic rate were compared in right non-irradiated (RO) kidneys and LI kidneys. Differences in H3T uptake were not significantly suppressed (P less than 0.05) by 4800 rad whereas mitoses in glomeruli and Bowman's capsule were not. Glomerular hypercellularity and crescents were equivalent in LI given 4800 rad and in RO kidneys, but fibrin deposition was increased 2-fold in LI kidneys. In control rabbits (no NTS) LI kidneys showed no histological changes. The results suggest that most dividing cells detected in glomeruli and Bowman's space in NTN are monocytes, and that these cells form a large component of crescents.