title: Pretreatment of sildenafil attenuates ischemia-reperfusion renal injury in rats.
abstract: Sildenafil was the first selective inhibitor of phosphodiesterase-5 (PDE5) to be widely used for treating erectile dysfunction. Many recent studies have investigated the cardioprotective role of sildenafil in animal models. We evaluated the protective effects of sildenafil in experimental renal ischemia-reperfusion (IR) injury in two studies. In study 1, male Sprague-Dawley rats were divided into four groups: sham, sildenafil-treated sham, vehicle-treated IR, and sildenafil-treated IR groups. In study 2, we divided the rats into two groups: sildenafil-treated IR rats and PD98059 (ERK inhibitor)+sildenafil-treated IR rats. Functional parameters of the kidney were evaluated at the molecular and structural levels. Blood urea nitrogen (BUN) and serum creatinine levels were lower in sildenafil-treated IR rats than in vehicle-treated IR rats. The expression of inducible (iNOS) and endothelial nitric oxide synthase (eNOS) proteins in sildenafil-treated IR rats was significantly higher than in vehicle-treated IR rats. Pretreatment with sildenafil in IR rats increased ERK phosphorylation and reduced the renal Bax/Bcl-2 ratio, renal caspase-3 activity, and terminal dUTP nick end-labeling-positive apoptotic cells. In contrast, PD98059 treatment increased BUN and serum creatinine levels and attenuated the sildenafil-induced expression of pERK, iNOS, eNOS, and Bcl-2. PD98059 also increased caspase-3 activity but did not decrease the sildenafil-induced accumulation of cGMP. In conclusion, this study suggests that sildenafil has antiapoptotic effects in experimental IR renal injury via ERK phosphorylation, induction of iNOS and eNOS production, and a decrease in the Bax/Bcl-2 ratio.
authors.affiliation: Internal Medicine, Chungnam National University Hospital, Daejeon, Republic of Korea.
authors.forename: Dae Eun
authors.initials: DE
authors.lastname: Choi
authors.forename: Jin Young
authors.initials: JY
authors.lastname: Jeong
authors.forename: Beom Jin
authors.initials: BJ
authors.lastname: Lim
authors.forename: Sarah
authors.initials: S
authors.lastname: Chung
authors.forename: Yoon Kyung
authors.initials: YK
authors.lastname: Chang
authors.forename: Sang Ju
authors.initials: SJ
authors.lastname: Lee
authors.forename: Ki Ryang
authors.initials: KR
authors.lastname: Na
authors.forename: Seok Young
authors.initials: SY
authors.lastname: Kim
authors.forename: Young Tai
authors.initials: YT
authors.lastname: Shin
authors.forename: Kang Wook
authors.initials: KW
authors.lastname: Lee
mesh_terms: D000818:Animals; D017209:Apoptosis / Q000187:drug effects; D001806:Blood Urea Nitrogen; D053148:Caspase 3 / Q000378:metabolism; D003404:Creatinine / Q000097:blood; D006152:Cyclic GMP / Q000378:metabolism; D054706:Cyclic Nucleotide Phosphodiesterases, Type 5 / Q000378:metabolism; D004195:Disease Models, Animal; D004334:Drug Administration Schedule; D048049:Extracellular Signal-Regulated MAP Kinases / Q000037:antagonists & inhibitors / Q000378:metabolism; D005419:Flavonoids / Q000008:administration & dosage; D007674:Kidney Diseases / Q000201:enzymology / Q000473:pathology / Q000517:prevention & control*; D008297:Male; D052247:Nitric Oxide Synthase Type II / Q000378:metabolism; D052250:Nitric Oxide Synthase Type III / Q000378:metabolism; D058986:Phosphodiesterase 5 Inhibitors; D010726:Phosphodiesterase Inhibitors / Q000008:administration & dosage*; D010766:Phosphorylation; D010879:Piperazines / Q000008:administration & dosage*; D047428:Protein Kinase Inhibitors / Q000008:administration & dosage; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000378:metabolism; D011687:Purines / Q000008:administration & dosage; D051381:Rats; D017207:Rats, Sprague-Dawley; D015427:Reperfusion Injury / Q000201:enzymology / Q000473:pathology / Q000517:prevention & control*; D000068677:Sildenafil Citrate; D013450:Sulfones / Q000008:administration & dosage*; D013997:Time Factors; D051028:bcl-2-Associated X Protein / Q000378:metabolism
chemical_list: C494828:Bax protein, rat; D005419:Flavonoids; D058986:Phosphodiesterase 5 Inhibitors; D010726:Phosphodiesterase Inhibitors; D010879:Piperazines; D047428:Protein Kinase Inhibitors; D019253:Proto-Oncogene Proteins c-bcl-2; D011687:Purines; D013450:Sulfones; D051028:bcl-2-Associated X Protein; D003404:Creatinine; D000068677:Sildenafil Citrate; D052247:Nitric Oxide Synthase Type II; D052250:Nitric Oxide Synthase Type III; C496318:Nos2 protein, rat; C496316:Nos3 protein, rat; D048049:Extracellular Signal-Regulated MAP Kinases; D054706:Cyclic Nucleotide Phosphodiesterases, Type 5; C505410:Casp3 protein, rat; D053148:Caspase 3; D006152:Cyclic GMP; C093973:2-(2-amino-3-methoxyphenyl)-4H-1-benzopyran-4-one