Differentiation in vivo of the sequential blood cell invasion following ureter obstruction of the rabbit kidney

Inflammatory cellular changes occurring during renal injury as a consequence of unilateral ureter obstruction were studied in vivo using 111In-labeled leukocytes and 111In-labeled platelets. The radiolabeled cells were administered at various times after induction of hydronephrosis by unilateral ureter ligation in New Zealand rabbits. The contralateral kidney (CLK) served as the control. The migration and accumulation of the radiolabeled cells was monitored by dual isotope scintigraphic imaging (i.e. 99mTc-labeled red blood cell subtraction) and confirmed by direct analysis of removed epsilateral hydronephrotic kidney (HNK) and CLK at the time of sacrifice. When 111In platelets were administered, significantly greater uptake in the hydronephrotic kidney was observed within 15 min of ureter ligation. Furthermore, the HNK accumulated twice the amount of 111In radioactivity than the CLK, when either the polymorphonuclear neutrophils (PMN) or monocytes were injected at the time of ureter obstruction. The differences between HNK and CLK were scintigraphically detectable between 6 and 12 h after hydronephrosis respectively; and 111In-labeled monocytes selectively accumulated in HNK if administered during the first 48 h after ureter ligation. These data suggest that inflammatory cells sequentially accumulate following ureter obstruction and are derived from circulating white blood cells. (author)