Original Article

Background. The pathogenesis of hyponatraemia caused by fluoxetine (Fx) use in the treatment of depression is not well understood. It has been attributed to a SIADH, although ADH-enhanced plasma level has not yet been demonstrated in all the cases reported in humans. This ex-periment aimed at investigating the effect of fluoxetine on the kidney and more specifically in the inner medullary collecting duct (IMCD). Methods. (1) In vivo study: (a) 10 rats were injected daily i.p. with 10 mg/kg fluoxetine doses. After 10 days, rats were sacrificed and blood and kidneys were collected. (b) Immunoblotting studies for AQP2 protein expression in the IMCD from injected rats and in IMCD tubules suspen-sion from 10 normal rats incubated with 10−7 M fluoxetine