<p>Sir,</p> <p>Recently, we published an article in J Res Med Sci, entitled "Ameliorative effects of metformin on renal histologic and biochemical alterations of gentamicin-induced renal toxicity in Wistar rats." <sup> <xref ref-type="bibr" rid="ref1">1</xref> </sup>In this article, it is concluded that metformin (MF) may prevent or ameliorate GM-induced acute renal failure, and therefore, it might be beneficial in patients under treatment with this medicine. <sup> <xref ref-type="bibr" rid="ref1">1</xref> </sup>In this letter, we would like to point out a few points about the mentioned conclusion. In an agreement with our findings, Taheri et al. recently conducted a study on the effects of MF on renal function and structure after unilateral ischemia-reperfusion in rat. They found that MF provided some renal protection against ischemia and reperfusion (I/R) induced injury to the rats kidney. They concluded that MF with activation of adenosine monophosphate-activated protein kinase (AMPK) and endothelial nitric oxide synthase have tissue protective effects. <sup> <xref ref-type="bibr" rid="ref2">2</xref> </sup>More recently, Kim et al. performed a study using MF (350 mg/kg/day) for spontaneously diabetic Torii (SDT) rats for 17 weeks. They examined blood glucose, glycated hemoglobin and albuminuria, kidney histopathology, renal 8-hydroxydeoxyguanosine levels, and also apoptosis. They found that treatment of SDT rats with MF restored podocyte loss. They suggested that diabetes-induced podocyte loss in diabetic nephropathy could be suppressed by MF, through the repression of oxidative injury. <sup> <xref ref-type="bibr" rid="ref3">3</xref> </sup></p> <p>Diabetic nephropathy is one of the most important complication of diabetes mellitus <sup> <xref ref-type="bibr" rid="ref4">4</xref> </sup>, <sup> <xref ref-type="bibr" rid="ref5">5</xref> </sup>and MF has been widely used for treatment of type 2 diabetes. <sup> <xref ref-type="bibr" rid="ref3">3</xref> </sup>, <sup> <xref ref-type="bibr" rid="ref4">4</xref> </sup>Thus according to our results and those published by Taheri et al., MF protects against tubular injury by restoring the biochemical alterations and modulation of oxidative stress on the tubules. <sup> <xref ref-type="bibr" rid="ref1">1</xref> </sup>, <sup> <xref ref-type="bibr" rid="ref2">2</xref> </sup>Moreover, according to the study by Kim et al., MF protects podocytes in diabetic nephropathy, <sup> <xref ref-type="bibr" rid="ref3">3</xref> </sup>while in diabetic nephropathy, there is also tubular cell injury due to glocosuria. <sup> <xref ref-type="bibr" rid="ref3">3</xref> </sup>, <sup> <xref ref-type="bibr" rid="ref4">4</xref> </sup>, <sup> <xref ref-type="bibr" rid="ref5">5</xref> </sup>, <sup> <xref ref-type="bibr" rid="ref6">6</xref> </sup>, <sup> <xref ref-type="bibr" rid="ref7">7</xref> </sup>These findings can more potentiate the clinical use of MF in the prevention of diabetic nephropathy. In this regard, to understand the MF-nephroprotective properties better, more experimental rat model or clinical studies are suggested.</p> </sec> </body> <back> <ref-list> <ref id="ref1"> <label>1</label> <nlm-citation citation-type="journal"> <person-group person-group-type="author"> <name> <surname>Amini</surname> <given-names>FG</given-names> </name> <name> <surname>Rafieian-Kopaei</surname> <given-names>M</given-names> </name> <name> <surname>Nematbakhsh</surname> <given-names>M</given-names> </name> <name> <surname>Baradaran</surname> <given-names>A</given-names> </name> <name> <surname>Nasri</surname> <given-names>H</given-names> </name> </person-group> <article-title>Ameliorative effects of metformin on renal histologic and biochemical alterations of gentamicin-induced renal toxicity in Wistar rats</article-title> <source>J Res Med Sci</source> <year>2012</year> <volume>17</volume> <fpage>621</fpage> <lpage>5</lpage> </nlm-citation> </ref> <ref id="ref2"> <label>2</label> <nlm-citation citation-type="journal"> <person-group person-group-type="author"> <name> <surname>Taheri</surname> <given-names>N</given-names> </name> <name> <surname>Azarmi</surname> <given-names>Y</given-names> </name> <name> <surname>Neshat</surname> <given-names>M</given-names> </name> <name> <surname>Garjani</surname> <given-names>A</given-names> </name> <name> <surname>Doustar</surname> <given-names>Y</given-names> </name> </person-group> <article-title>Study the effects of metformin on renal function and structure after unilateral ischemia-reperfusion in rat</article-title> <source>Res Pharm Sci ;()</source> <year>5)</year> <volume></volume> <fpage></fpage> <comment>Study the effects of metformin on renal function and structure after unilateral ischemia-reperfusion in rat Res Pharm Sci 2012;7(5)</comment> </nlm-citation> </ref> <ref id="ref3"> <label>3</label> <nlm-citation citation-type="journal"> <person-group person-group-type="author"> <name> <surname>Kim</surname> <given-names>J</given-names> </name> <name> <surname>Shon</surname> <given-names>E</given-names> </name> <name> <surname>Kim</surname> <given-names>CS</given-names> </name> <name> <surname>Kim</surname> <given-names>JS</given-names> </name> </person-group> <article-title>Renal podocyte injury in a rat model of type 2 diabetes is prevented by metformin</article-title> <source>Exp Diabetes Res</source> <year>2012</year> <volume>2012</volume> <fpage>210821</fpage> </nlm-citation> </ref> <ref id="ref4"> <label>4</label> <nlm-citation citation-type="journal"> <person-group person-group-type="author"> <name> <surname>Baradaran</surname> <given-names>A</given-names> </name> </person-group> <article-title>Lipoprotein (a), type 2 diabetes and nephropathy; the mystery continues</article-title> <source>J Nephropathology</source> <year>2012</year> <volume>1</volume> <fpage>126</fpage> <lpage>9</lpage> </nlm-citation> </ref> <ref id="ref5"> <label>5</label> <nlm-citation citation-type="journal"> <person-group person-group-type="author"> <name> <surname>Rahimi</surname> <given-names>Z</given-names> </name> </person-group> <article-title>ACE insertion/deletion (I/D) polymorphism and diabetic nephropathy</article-title> <source>J Nephropathology</source> <year>2012</year> <volume>1</volume> <fpage>143</fpage> <lpage>51</lpage> </nlm-citation> </ref> <ref id="ref6"> <label>6</label> <nlm-citation citation-type="journal"> <person-group person-group-type="author"> <name> <surname>Tolouian</surname> <given-names>R</given-names> </name> <name> <surname>Hernandez</surname> <given-names>GT</given-names> </name> </person-group> <article-title>Prediction of diabetic nephropathy: The need for a sweet biomarker.J Nephropathology</article-title> <source></source> <year>2013</year> <volume>2</volume> <fpage>4</fpage> <lpage>5</lpage> </nlm-citation> </ref> <ref id="ref7"> <label>7</label> <nlm-citation citation-type="journal"> <person-group person-group-type="author"> <name> <surname>Tavafi</surname> <given-names>M</given-names> </name> </person-group> <article-title>Complexity of diabetic nephropathy pathogenesis and design of investigations</article-title> <source>J Ren Inj Prev</source> <year>2013</year> <volume>2(2)</volume> <fpage>61</fpage> <lpage>5</lpage> </nlm-citation> </ref> <ref id="ref8"> <label>8</label> <nlm-citation citation-type="journal"> <person-group person-group-type="author"></person-group> <article-title></article-title> <source></source> <year></year> <volume></volume> <fpage></fpage> </nlm-citation> </ref> </ref-list> </back> </article>

JRMS

J Res Med Sci

Journal of Research in Medical Sciences

1735-1995 1735-7136

Medknow Publications Pvt Ltd

India

JRMS-18-628

Letter To Editor

Ameliorative effects of metformin on renal histologic and biochemical alterations of gentamicin-induced renal toxicity in Wistar rats

Nasri

Hamid

Department of Nephrology, Division of Nephropathology, Isfahan University of Medical Sciences, Isfahan, Iran

Address for correspondence:Hamid Nasri, Department of Nephrology, Division of Nephropathology, Isfahan University of Medical Sciences, Isfahan, Iran hamidnasri@med.mui.ac.ir

July 2013

18 7 628 628

2013

This is an open-access article distributed under the terms of the Creative Commons Attribution-Noncommercial-Share Alike 3.0 Unported, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

<p>Sir,</p> <p>Recently, we published an article in J Res Med Sci, entitled "Ameliorative effects of metformin on renal histologic and biochemical alterations of gentamicin-induced renal toxicity in Wistar rats." <sup> <xref ref-type="bibr" rid="ref1">1</xref> </sup>In this article, it is concluded that metformin (MF) may prevent or ameliorate GM-induced acute renal failure, and therefore, it might be beneficial in patients under treatment with this medicine. <sup> <xref ref-type="bibr" rid="ref1">1</xref> </sup>In this letter, we would like to point out a few points about the mentioned conclusion. In an agreement with our findings, Taheri et al. recently conducted a study on the effects of MF on renal function and structure after unilateral ischemia-reperfusion in rat. They found that MF provided some renal protection against ischemia and reperfusion (I/R) induced injury to the rats kidney. They concluded that MF with activation of adenosine monophosphate-activated protein kinase (AMPK) and endothelial nitric oxide synthase have tissue protective effects. <sup> <xref ref-type="bibr" rid="ref2">2</xref> </sup>More recently, Kim et al. performed a study using MF (350 mg/kg/day) for spontaneously diabetic Torii (SDT) rats for 17 weeks. They examined blood glucose, glycated hemoglobin and albuminuria, kidney histopathology, renal 8-hydroxydeoxyguanosine levels, and also apoptosis. They found that treatment of SDT rats with MF restored podocyte loss. They suggested that diabetes-induced podocyte loss in diabetic nephropathy could be suppressed by MF, through the repression of oxidative injury. <sup> <xref ref-type="bibr" rid="ref3">3</xref> </sup></p> <p>Diabetic nephropathy is one of the most important complication of diabetes mellitus <sup> <xref ref-type="bibr" rid="ref4">4</xref> </sup>, <sup> <xref ref-type="bibr" rid="ref5">5</xref> </sup>and MF has been widely used for treatment of type 2 diabetes. <sup> <xref ref-type="bibr" rid="ref3">3</xref> </sup>, <sup> <xref ref-type="bibr" rid="ref4">4</xref> </sup>Thus according to our results and those published by Taheri et al., MF protects against tubular injury by restoring the biochemical alterations and modulation of oxidative stress on the tubules. <sup> <xref ref-type="bibr" rid="ref1">1</xref> </sup>, <sup> <xref ref-type="bibr" rid="ref2">2</xref> </sup>Moreover, according to the study by Kim et al., MF protects podocytes in diabetic nephropathy, <sup> <xref ref-type="bibr" rid="ref3">3</xref> </sup>while in diabetic nephropathy, there is also tubular cell injury due to glocosuria. <sup> <xref ref-type="bibr" rid="ref3">3</xref> </sup>, <sup> <xref ref-type="bibr" rid="ref4">4</xref> </sup>, <sup> <xref ref-type="bibr" rid="ref5">5</xref> </sup>, <sup> <xref ref-type="bibr" rid="ref6">6</xref> </sup>, <sup> <xref ref-type="bibr" rid="ref7">7</xref> </sup>These findings can more potentiate the clinical use of MF in the prevention of diabetic nephropathy. In this regard, to understand the MF-nephroprotective properties better, more experimental rat model or clinical studies are suggested.</p> </sec> </body> <back> <ref-list> <ref id="ref1"> <label>1</label> <nlm-citation citation-type="journal"> <person-group person-group-type="author"> <name> <surname>Amini</surname> <given-names>FG</given-names> </name> <name> <surname>Rafieian-Kopaei</surname> <given-names>M</given-names> </name> <name> <surname>Nematbakhsh</surname> <given-names>M</given-names> </name> <name> <surname>Baradaran</surname> <given-names>A</given-names> </name> <name> <surname>Nasri</surname> <given-names>H</given-names> </name> </person-group> <article-title>Ameliorative effects of metformin on renal histologic and biochemical alterations of gentamicin-induced renal toxicity in Wistar rats</article-title> <source>J Res Med Sci</source> <year>2012</year> <volume>17</volume> <fpage>621</fpage> <lpage>5</lpage> </nlm-citation> </ref> <ref id="ref2"> <label>2</label> <nlm-citation citation-type="journal"> <person-group person-group-type="author"> <name> <surname>Taheri</surname> <given-names>N</given-names> </name> <name> <surname>Azarmi</surname> <given-names>Y</given-names> </name> <name> <surname>Neshat</surname> <given-names>M</given-names> </name> <name> <surname>Garjani</surname> <given-names>A</given-names> </name> <name> <surname>Doustar</surname> <given-names>Y</given-names> </name> </person-group> <article-title>Study the effects of metformin on renal function and structure after unilateral ischemia-reperfusion in rat</article-title> <source>Res Pharm Sci ;()</source> <year>5)</year> <volume></volume> <fpage></fpage> <comment>Study the effects of metformin on renal function and structure after unilateral ischemia-reperfusion in rat Res Pharm Sci 2012;7(5)</comment> </nlm-citation> </ref> <ref id="ref3"> <label>3</label> <nlm-citation citation-type="journal"> <person-group person-group-type="author"> <name> <surname>Kim</surname> <given-names>J</given-names> </name> <name> <surname>Shon</surname> <given-names>E</given-names> </name> <name> <surname>Kim</surname> <given-names>CS</given-names> </name> <name> <surname>Kim</surname> <given-names>JS</given-names> </name> </person-group> <article-title>Renal podocyte injury in a rat model of type 2 diabetes is prevented by metformin</article-title> <source>Exp Diabetes Res</source> <year>2012</year> <volume>2012</volume> <fpage>210821</fpage> </nlm-citation> </ref> <ref id="ref4"> <label>4</label> <nlm-citation citation-type="journal"> <person-group person-group-type="author"> <name> <surname>Baradaran</surname> <given-names>A</given-names> </name> </person-group> <article-title>Lipoprotein (a), type 2 diabetes and nephropathy; the mystery continues</article-title> <source>J Nephropathology</source> <year>2012</year> <volume>1</volume> <fpage>126</fpage> <lpage>9</lpage> </nlm-citation> </ref> <ref id="ref5"> <label>5</label> <nlm-citation citation-type="journal"> <person-group person-group-type="author"> <name> <surname>Rahimi</surname> <given-names>Z</given-names> </name> </person-group> <article-title>ACE insertion/deletion (I/D) polymorphism and diabetic nephropathy</article-title> <source>J Nephropathology</source> <year>2012</year> <volume>1</volume> <fpage>143</fpage> <lpage>51</lpage> </nlm-citation> </ref> <ref id="ref6"> <label>6</label> <nlm-citation citation-type="journal"> <person-group person-group-type="author"> <name> <surname>Tolouian</surname> <given-names>R</given-names> </name> <name> <surname>Hernandez</surname> <given-names>GT</given-names> </name> </person-group> <article-title>Prediction of diabetic nephropathy: The need for a sweet biomarker.J Nephropathology</article-title> <source></source> <year>2013</year> <volume>2</volume> <fpage>4</fpage> <lpage>5</lpage> </nlm-citation> </ref> <ref id="ref7"> <label>7</label> <nlm-citation citation-type="journal"> <person-group person-group-type="author"> <name> <surname>Tavafi</surname> <given-names>M</given-names> </name> </person-group> <article-title>Complexity of diabetic nephropathy pathogenesis and design of investigations</article-title> <source>J Ren Inj Prev</source> <year>2013</year> <volume>2(2)</volume> <fpage>61</fpage> <lpage>5</lpage> </nlm-citation> </ref> <ref id="ref8"> <label>8</label> <nlm-citation citation-type="journal"> <person-group person-group-type="author"></person-group> <article-title></article-title> <source></source> <year></year> <volume></volume> <fpage></fpage> </nlm-citation> </ref> </ref-list> </back> </article>