The present study was aimed at investigating whether an altered role of nitric oxide (NO) is involved in chronic renal failure (CRF). Rats were subjected to 5/6 nephrectomy and kept for 6 weeks to induce CRF. On the experimental day, after measurement of arterial pressure under anesthesia, the arterial blood was collected, and thoracic aorta and kidney were rapidly taken. NO metabolites (NOx) were determined in the plasma, urine, aorta and kidney. The expression of NO synthase (NOS) isozymes was determined in the kidney and aorta by Western blot analysis. The expression of NOS mRNA in the glomeruli was also determined by RT-PCR. There were significant increases in arterial pressure and serum creatinine levels in CRF. Urine NOx levels were decreased in CRF, whereas plasma NOx levels were not altered. Aorta and kidney tissue NOx levels were also decreased in CRF. The expression of endothelial constitutive (ec) and inducible (i) isoforms of NOS proteins was decreased in the kidney and aorta in CRF. Accordingly, the expression of ecNOS and iNOS mRNA was decreased in the glomeruli in CRF. In conclusion, NO synthesis is decreased in the kidney and vasculature of CRF rats.
Animal ; Aorta, Thoracic/metabolism ; Comparative Study ; Enzyme Induction ; Isoenzymes/metabolism+ACo- ; Isoenzymes/genetics ; Kidney/metabolism ; Kidney Failure, Chronic/metabolism+ACo- ; Male ; Nephrectomy ; Nitrates/urine ; Nitrates/blood ; Nitric Oxide/deficiency+ACo- ; Nitric Oxide/biosynthesis ; Nitric-Oxide Synthase/metabolism+ACo- ; Nitric-Oxide Synthase/genetics ; Nitrites/urine ; Nitrites/blood ; Organ Specificity ; RNA, Messenger/biosynthesis ; Rats ; Rats, Sprague-Dawley

The present study was aimed at investigating whether an altered role of nitric oxide (NO) is involved in chronic renal failure (CRF). Rats were subjected to 5/6 nephrectomy and kept for 6 weeks to induce CRF. On the experimental day, after measurement of arterial pressure under anesthesia, the arterial blood was collected, and thoracic aorta and kidney were rapidly taken. NO metabolites (NOx) were determined in the plasma, urine, aorta and kidney. The expression of NO synthase (NOS) isozymes was determined in the kidney and aorta by Western blot analysis. The expression of NOS mRNA in the glomeruli was also determined by RT-PCR. There were significant increases in arterial pressure and serum creatinine levels in CRF. Urine NOx levels were decreased in CRF, whereas plasma NOx levels were not altered. Aorta and kidney tissue NOx levels were also decreased in CRF. The expression of endothelial constitutive (ec) and inducible (i) isoforms of NOS proteins was decreased in the kidney and aorta in CRF. Accordingly, the expression of ecNOS and iNOS mRNA was decreased in the glomeruli in CRF. In conclusion, NO synthesis is decreased in the kidney and vasculature of CRF rats.
Animal ; Aorta, Thoracic/metabolism ; Comparative Study ; Enzyme Induction ; Isoenzymes/metabolism+ACo- ; Isoenzymes/genetics ; Kidney/metabolism ; Kidney Failure, Chronic/metabolism+ACo- ; Male ; Nephrectomy ; Nitrates/urine ; Nitrates/blood ; Nitric Oxide/deficiency+ACo- ; Nitric Oxide/biosynthesis ; Nitric-Oxide Synthase/metabolism+ACo- ; Nitric-Oxide Synthase/genetics ; Nitrites/urine ; Nitrites/blood ; Organ Specificity ; RNA, Messenger/biosynthesis ; Rats ; Rats, Sprague-Dawley

OBJECTIVES: The aging process affects responsiveness and other functions of endothelium and vascular smooth muscle cells, predisposing the old vessels to the development of atherosclerotic lesions. Endothelial nitric oxide synthase (ecNOS) gene polymorphisms were shown to affect the occurrence of acute myocardial infarction (AMI). We hypothesized that aging may affect the association between the ecNOS gene polymorphism and AMI. METHODS: We investigated the age-related distribution of the ecNOS gene a/b polymorphism in 121 male AMI patients and 206 age-matched healthy male controls. RESULTS: The aa, ab and bb genotypes were found in 1, 49 and 156 cases among the control subjects and 5, 23 and 93 cases among the AMI patients, respectively. There was a significant correlation between the ecNOS polymorphism and AMI (p +AD0- 0.045). When the correlation was analyzed by age, the significance remained only in the group below the age of 51 (p +AD0- 0.009). The proportion of smokers was increased in the young patients when compared to the old patients (p +AD0- 0.033), indicating that smoking also has greater effect on the younger population. The incidences of hypertension and diabetes mellitus, however, were similar in both populations. CONCLUSION: Our work provides the first evidence that links ecNOS polymorphism to the risk of AMI in relation to age. Young persons who smoke or have ecNOSaa genotype may have an increased risk of developing AMI. The functional as well as structural changes associated with aging in the vascular endothelium may mask the effect of the ecNOS polymorphism in the development of AMI in old persons.
Adult ; Age Distribution ; Aged ; Aged, 80 and over ; Aging/physiology+ACo- ; Chi-Square Distribution ; Comorbidity ; Diabetes Mellitus/epidemiology ; Endothelium, Vascular/enzymology+ACo- ; Genotype ; Human ; Hypertension/epidemiology ; Korea/epidemiology ; Male ; Middle Age ; Myocardial Infarction/physiopathology+ACo- ; Myocardial Infarction/epidemiology ; Nitric-Oxide Synthase/metabolism+ACo- ; Nitric-Oxide Synthase/genetics+ACo- ; Polymerase Chain Reaction ; Polymorphism (Genetics)+ACo- ; Risk Assessment ; Statistics, Nonparametric