EFFECTS OF SWL ON GLOMERULAR-FILTRATION RATE AND RENAL PLASMA-FLOW INUNINEPHRECTOMIZED MINIPIGS

This study tested the hypothesis that the effects of SWL on hemodynami cs in solitary kidneys differ from those in kidneys of binephric anima ls, Five female miniature pigs (Pitman-Moore, 6 months of age, 30-35 k g) were anesthetized for unilateral nephrectomy, Seven pigs served as binephric controls, Two weeks later, each pig was anesthetized, prepar ed for unilateral or bilateral urine collections, and subjected to SWL (Dornier HM3, 2000 shocks, 24 kV), Clearances of inulin (glomerular f iltration rate; GFR) and para-aminohippurate (renal plasma flow; RPF) were measured 1 hour prior to and 1, 4, and 24 hours after SWL, The GF R and RPF were higher in uninephrectomized than in intact pigs at all time points, In both groups, SWL reduced GFR and RPF, In the binephric pigs, RPF was reduced at all times post-SWL, but in the uninephrectom ized pigs, RPF was returning toward baseline by 4 hours post-SWL and w as not different from baseline at 24 hours. A comparison of whole-anim al GFR and RPF (right plus left clearances in binephric pigs v solitar y renal clearances in uninephrectomized pigs) showed that whole-animal GFR and RPF did not differ between the groups before or after SWL, Co mpensatory renal hypertrophy and improved hemodynamics in solitary kid neys may acutely attenuate the renal vasoconstrictive effects of SWL, The long-term consequences of the compensatory changes are unknown.