ABSTRACT
Immunosuppressive therapy and uremia complicate the mechanisms involved in renal functional changes after kidney transplantation. Glomerular filtration rate [GFR] is attenuated after renal ischemia, whereas it increases after denervation, both are important factors in renal transplantation. A defect in renal handling of Na[+] in response to volume expansion in some reports of renal transplantation was also recorded. The aim of the present work was to study the functional capacity of auto-and homotransplanted canine kidneys after a sodium chloride load. Four groups each comprising six mongrel dogs were used in the present study: Group I: autotransplanted animals where GFR and kidney excretory functions were investigated immediately after transplantation. Group II: Like group I but the investigations were performed 5 days after autotransplantation. Group III: Animals with homotransplantation were subjected to the same investigation, as before, immediately after the operation. Group IV: The group of donors of the kidney to group III. And the remaining kidney served as the control for that of group III whose two kidneys were taken off just before the transplantation. Inulin was infused I. V. to study inulin clearance [C[IN], normal saline was also infused for 60 min then 5% NaCl solution for another 60 min. [Na[+] load. Arterial blood and urine samples were collected by catheter inserted in femoral artery and ureters of transplanted and control animal and the following parameters were investigated: Urinary excretion rate v C[IN] urinary excretion rate for Na[+], Cl[-] and K[+] [UE[Na]+, UE[cI-]- and UE[k], fractional excretion of Na[+] [FE[Na]+%] for group I, II, III and IV of animals [UK[Nn] or K[+] group I, II, III, IV of animals. Two collection periods were done, the first [60 min] with normal saline infusion and the second [60 min] with saline load. There were decreased values for v GFR [IN] UE[Na+] and UE[K+] FE[Na+%] compared to control in group I, III, UE[CI-] of group I showed no significant change. After 5 days of autotransplantation [gp II] UE[Na+] and FE[Na+]% were significantly increased compared to their control, v and GFR decreased and UE[CI-]- and UE[K+] did not change significantly from their control. After infusion of NaCl load v of group III increased there was insignificant change of UE[Na+] and UE[K+] for group II and increase of FE[Na+]% and significant increase of all parameters, of group I with the exception of C[IN] which decreased. There was significant decrease of all other parameters of the 3 groups as compared to their controls. Transplanted kidneys [auto or homo] behave functionally different from that after ischemia or denervation. Transplanted kidney can excrete a saline load and increase its GFR inspite of denervation and ischemia and this may be attributed to some humoral factors concerned with rennin angiotensin system [RAS] or atrial natriuretic peptide [ANP] or attenuation of sympathetic nervous system control. Care should be directed to the fluid and electrolytes [especially [K+]] infused to patients immediately following auto-or homotransplantation