Study of some renal functions after calcium and calcium channel blockers in normal and gentamycin-treated rats

ABSTRACT

Gentamycin nephrotoxicity occurs in a substantial proportion of patients receiving this drug. Animal studies have shown that dietary calcium diminishes the severity of this renal damage. Thus, the aim of the present work was to demonstrate the effect of Ca[+2] and Ca[+2] channel blocker verapamil on some renal functions in rats. 60 adult male albino rats were divided into six groups serving as control, verapamil-treated, gentamycin-treated, verapamil-gentamycin treated, given excess Ca[+2] alone, and lastly those receiving gentamycin with excess Ca[+2] in diet. Serum Na[+], K[+], creatinine clearance and Na+K+-ATPase activity in kidney tissue homogenate were determined 48 hours after last injection. There were impaired renal functions after treatment with gentamycin and was manifested by hypokalaemia, decreased creatinine clearance and Na[+] K[+]ATPase activity. These effects were more severe in rats treated with combined gentamycin and verapamil than gentamycin alone. Also, high dietary Ca[+] reduced gentamycin nephrotoxicity. This indicates that verapamil increases the severity of gentamycin nephrotoxicity as it inhibits mobilization of Ca[+2] across cellular and intracellular membranes