Antioxidant Effect Of Melatonin On Renal Vascular Hypertension In Rats Kidney

Objective Through observe the inhibitive effect of melatonin (MT) on renal hypertension injury-induced tubular cell impairment in order to investigate its mechanisms.Methods Two-kidney-one-clip (2K1C) models were made with male Wistar rats (about180-220g). Those blood pressures equal to or higher than140mmHg were enrolled and divided randomly into2groups as follows:The positive control group (CONT), the MT group. There are8rats in each group. Eight sham rats were fed as negative controls. Animals were monitored and sacrificed at8th week. The morphological changes of renal tissues were observed by hematoxylin and eosin (HE) and Masson staining. Renal tissue superoxide dismutase (SOD) and malondialdehyde (MDA) content were detected by colorimetric method. The inducible nitric oxide synthase and endothelial nitric oxide synthase of right renal tissue were detected by immunohistochemical method and reverse transcription-polymerase chain reaction (RT-PCR).Results①Compared with SHAM group, kidneys displayed a severer pathological injuries in CONT group by HE and Masson, Renal tubular epithelial cell vacuoles, inflammatory and granular degeneration cells infiltrating, renal tubular edema expansion, even atrophy, compared with CONT group, kidneys displayed a palliative pathological injuries in MT group by HE;②Four weeks after2K1C, blood pressure of CONT group is significantly higher than SHAM group, but melatonin can significantly inhibit rat blood rise;③ompared with SHAM group, blood pressure and MDA measurement is severely increase in hypertensive group (P<0.05) SOD measurement is severely decrease in hypertensive group (P<0.05), compared with CONT group, blood pressure and MDA measurement is severely decrease in MT group (P<0.05), SOD measurement is severely increase in MT group (P<0.05);④In immunohistochemical method and RT-PCR, in CONT group, the activity of eNOS decreased significantly compared with SHAM group (P<0.05), the activity of iNOS increased severely compared with SHAM group (P<0.05); in MT group, the activity of eNOS increased severely compared with CONT group (P<0.05), the activity of iNOS decreased significantly compared with CONT group (P<0.05).Conclusion Melatonin could inhibit the hypertension-induced tubular cell impairment, at least partly, which may be the result of the iNOS increasing and eNOS decreasing dependent pathway of oxidatie stress.