Key result
Hypertension and aging decrease tissue NO levels and are associated with reduced urinary excretion of NOS inhibitors, ADMA and SDMA, in male rats.
Why the study?
Decreased nitric oxide availability is linked to hypertension, cardiovascular, and kidney diseases, but the relationship between tissue nitric oxide levels and nitric oxide-related metabolites in plasma and urine needed evaluation.
Hypothesis-generating for NO pathways in hypertensive aging; leaves open human translation and clinical relevance.
Nitric oxide (NO) is one of the gaseous transmitters which play a very important role in the regulation of the circulatory system. Decreased NO availability is associated with hypertension, cardiovascular and kidney diseases. Endogenous NO is generated enzymatically by nitric oxide synthase (NOS) depending on the availability of the substrate, cofactors, or presence/absence of inhibitors, such as asymmetric dimethylarginine (ADMA) and symmetric dimethylarginine (SDMA). The objective of this study was to evaluate the potential relationship between NO level in rat tissues (heart and kidneys) and the concentrations of endogenous metabolites related to NO in plasma and urine. The experiment was carried out with 16- and 60-week-old male Wistar Kyoto (WKY) and age-matched male Spontaneously Hypertensive Rats (SHR). NO level in tissue homogenates was determined by the colorimetric method. RT-qPCR was used to verify the expression of the eNOS (endothelial NOS) gene. Plasma and urine concentrations of arginine, ornithine, citrulline, and dimethylarginines were examined by the UPLC-MS/MS method. 16-week-old WKY rats had the highest tissue NO and plasma citrulline levels. Furthermore, 16-week-old WKY rats showed higher urinary excretion of ADMA/SDMA compared to other experimental groups, however, plasma concentrations of arginine, ADMA, and SDMA were comparable between the groups. In conclusion, our research shows that hypertension and aging decrease tissue NO levels and are associated with reduced urinary excretion of NOS inhibitors, i.e., ADMA and SDMA.
No takes yet. Share an insight, caveat, or question.
Szlęzak et al. (2023) studied Hypertension. Hypertension and aging (SHR and 60-week-old rats) vs. Normotensive and young rats (WKY and 16-week-old rats) was evaluated on Relationship between NO level in rat tissues (heart and kidneys) and concentrations of endogenous metabolites related to NO in plasma and urine. Hypertension and aging decrease tissue NO levels and are associated with reduced urinary excretion of NOS inhibitors, ADMA and SDMA, in male rats.
Synapse has enriched 5 closely related papers on similar clinical questions. Consider them for comparative context: