Evaluation of the effects of S-methylisothiourea hemisulfate, an inducible nitric oxide synthase inhibitor, on the healing of colonic anastomosis in rats

Abstract

PURPOSE:To evaluate the effects of S-methylisothiourea hemisulfate (SMT) on the healing of colonic anastomosis in rats. METHODS:Sixty rats Wistar were distributed into two groups of 30 animals: experimental (E) and control C). The animals of experimental group received intraperitoneal SMT at 50mg/kg/dose every 12 hours for 72 hours. The control group received intraperitoneal saline at the same volume of SMT. The rats were subdivided into subgroups groups of 10 for euthanasia on the third, seventh, and 14 th postoperative days (POD). We evaluated clinical and weight evolution, breaking strength and histopathology; also, a blood sample was collected for serum dosage of nitrite/nitrate. RESULTS:There was more vascular neoformation (p=0.006) and granulation (p=0.002) in the E3 group, and more mononuclear infiltrates in the C3 group (p=0.041). There was also more edema in the C14 group (p=0.008). There was no statistically significant difference in breaking strength, nitrite/nitrate dosage, and the remaining histopathological parameters. CONCLUSION:The use of S-methylisothiourea hemisulfate improved the healing of colonic anastomosis in rats on the third postoperative day by accelerating the proliferative stage of healing, but without interfering with the breaking strength of the anastomosis. Key words: Nitric Oxide. Nitric Oxide Synthase. Wound Healing. Anastomosis, Surgical. Colon. Rats. RESUMO OBJETIVO:Avaliar os efeitos do hemissulfato de S-metilisotiouréia (SMT) na cicatrização de anastomoses colônicas em ratos no terceiro, sétimo e 14° dia de pós-operatório (DPO). MÉTODOS: Sessenta ratos Wistar foram distribuídos em dois grupos: experimental (E) e controle (C), com 30 animais cada. No grupoexperimental foi administrado SMT 50mg/kg/dose, intraperitoneal a cada 12 horas por 72 horas. O grupo controle recebeu NaCl a 0,9%.Os ratos foram subdivididos em grupos de 10 para eutanásia no terceiro, sétimo e 14° DPO. Avaliou-se a evolução clínica e o peso dos animais, a resistência tênsil e histopatologia da anastomose, e a dosagem de nitrito/nitrato no soro. RESULTADOS:Houve mais neoformação vascular (p=0,006) e de granulação (p=0,002) no grupo E3, e maior infiltração de mononucleares no grupo C3 (p=0,041). Houve também mais edema no grupo C14 (p=0,008). Não houve diferença estatisticamente significativa na resistência tênsil, a dosagem de nitrito / nitrato, e os restantes parâmetros histopatológicos. CONCLUSÃO:A utilização do hemissulfato de S-metilisotiouréia acelerou a cicatrização das anastomoses colônicas, a melhoria ocorreu no terceiro DPO: verificou-se que a fase proliferativa da cicatrização foi acelerada. Não houve interferência na resistência tênsil das anastomoses.Descritores: Óxido Nítrico. Oxido Nítrico Sintase. Cicatrização. Anastomose Cirúrgica. Colo. Ratos. Evaluation of the effects of S-methylisothiourea hemisulfate, an inducible nitric oxide synthase inhibitor, on the healing of colonic anastomosis in rats

The role of S-methylisothiourea hemisulfate as inducible nitric oxide synthase inhibitor against kidney iron deposition in iron overload rats

“…SMT is an iNOS inhibitor, and some studies have shown the specificity of SMT for iNOS. [ 12 15 ] Nitrite is also considered as an indicator of NO production. [ 16 ] We found that simultaneous use of SMT and iron did not attenuate the intensity of ID in the kidney.…”

“…The agent is shown to be 10–30 times more effective and powerful than other iNOS inhibitors in vitro . [ 12 ] SMT inhibits NO production, which in turn reduces endogenous NO concentration. [ 13 ] Due to increase of iNOS in some organs [ 10 11 ] by iron overloading, it is hypothesized that inhibition of iNOS may attenuate iron overloading or at least it's side effects.…”