Reply: oxytocin ameliorates cisplatin-induced nephrotoxicity in Wistar rats.

To the Editor: We read with great interest the recently published nice article in the esteemed “Ann Saudi Med”, by Elberry et al entitled “Oxytocin ameliorates cisplatin-induced nephrotoxicity in Wistar rats”.1 In an experimental study on 48 male Wistar albino rats, Elberry et al. aimed to study the ameliorative effects of oxytocin against cisplatin renal toxicity.1 They assessed the renal injury of cisplatin by performing histopathological study and by observing an increase in serum LDH activity as well as urea and creatinine levels. Furthermore, to asses renal injury, they also measured renal tissue activities of catalase, superoxide dismutase, glutathione peroxidase, and glutathione S-transferase as well as glutathione level. Also the renal tissue content of thiobarbituric acid–reactive substances, nitric oxide end-product nitrite, and the activity of myeloperoxidase were measured. They found that oxytocin protected rats from cisplatin-induced nephrotoxicity and attributedthis to the antioxidant activity of oxytocin.1 In this letter, I would like to point out a few points about cisplatin nephrotoxicity. In a preclinical study, we observed that estrogen attenuates the defending property of erythropoietin against cisplatin-induced renal toxicity in ovariectomized Wistar rats.2 We also observed that L-arginine had ameliorative effects against cisplatin-induced renal toxicity in male rats. Nevertheless, it intensifies the induced injury in female rats.3 In this study, we described a sex-related difference in the rat model of cisplatin nephrotoxicity.3 Since, the position of gender in cisplatin-induced renal toxicity is not reported from published reports, we conducted another preclinical study on the rat model of cisplatin nephrotoxicity. From the results of this study we found that losartan, as an angiotension receptor blocker, may prevent cisplatin nephrotoxicity in males, whereas it aggravates the cisplatin-induced tubular injury in female rats.4 We concluded that the sex-related difference of cisplatin nephrotoxicity may be related to the renin–angiotensin system receptors in the kidneys.4–9 In addition, we reported that, Vitamin E, Vitamin C, or losartan have not ameliorative effects against cisplatin-induced renal toxicity in the presence of estrogen in the ovariectomized rat model of cisplatin toxicity,10 which is in agreement with our previous results. Therefore, it is well established that there is a gender difference in the cisplatin-induced renal toxicity in the rat model. However, it is well recognized that some conditions leading to chronic kidney diseases are gender related too.5–9 Few studies published regarding gender difference in cisplatin-induced kidney toxicity. However, there still needs to more investigate mechanisms interact in cisplatin nephrotoxicity especially on gender difference.10,11 To better find the factor of sex difference in cisplatin nephrotoxicity, further experimental rat model or clinical studies recommended.