@EN This study was conducted to test the hypothesis that thyroxine has a protecitve effect on renal tubular injury induced by cisplatin (cis-diamminedichloroplatinum II). The changs in renal function, election, electrolyte concentrations, renal
cortical
Na+, K+ - ATPAase activity and alkaline phosphatase acctivity were measured in Sprague-Dawley rates divided into four groups. Seven normal (THY) and 7 cisplatin treated rats (CIS-THY) received thyroxine (10μg/100g of body weight/dose SC). Seven
additional cisplatin treated (CIS) and 11 normal control rats (NC) served as controls. Thyroxine was given daily for 7 days in THY and for 12 days from 7 days prior to the administration of cisplatin until 5 days after cisplatin administration in
CIS-THY group. cisplatin nephrotoxicity was induced by intraperitoneal administration of 5 mg/kg single dose of cisplatin.
Na+, K+-ATPase activity (μmole Pi/mg protein/hr) was decreased in CIS (20.8±4.6) compared with NC group (31.4±5.2, p,0.01). Contrarily, the enzyme activity was increase in THY (42.9±3.0, p<0,01) and CIS-THY(41.7±7.7 p<0.05) groups. Alkaline
phosphatase activity (μmole Pi/mg protein/hr) has decreased in CIS (2.6±0.8, p<0.01) an thyroxine treated THY (2.8±1.0, p<0.05) and CIS-THY (3.1±0.9, p<0.05) compared with NC group (4.2±1.1).
Nephrotoxicity was assessed by measuring serum BUN, creatinine and electrolytes. Serum BUN (mg/dl) and creatinine levels (mg/dl) were increased in CIS (144.2±44.4 and 5.0±2.7 compared with NC group (21.4±6.0 and 0.9±0.3, p<0.01). However,
s4erum BUN
and creatinine levels were unchanged in THY (18.1±2.7 and 0.7±0.1) and CIS-THY (18.7±3.8 and 0.7±0.1) groups.
The electrolytes were comparable in all four group.
Free thyroxine level (ng/dl) was decreased in significantly in CIS (9.36±1.65) but were increased in thyroxine treated THY (36.64±3.45) and CIS-THY (30.55±7.32) compared with NC group (14.34
4. 77, p<0.01).
These data indicates that thyroxine protect the kidney from cisplatin-induced nephrotoxicity by enhancing renal cortical Na+, K+-ATPasen activity.
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