Cutaneous neuronal nitric oxide is specifically decreased in postural tachycardia syndrome
Abstract
Low flow postural tachycardia syndrome (POTS), is associated with reduced nitric oxide (NO) activity assumed to be of endothelial origin. We tested the hypothesis that cutaneous microvascular neuronal NO (nNO) is impaired, rather than endothelial NO (eNO), in POTS. We performed three sets of experiments on subjects aged 22.5 +/- 2 yr. We used laser-Doppler flowmetry response to sequentially increase acetylcholine (ACh) doses and the local cutaneous heating response of the calf as bioassays for NO. During local heating we showed that when the selective neuronal nNO synthase (nNOS) inhibitor N(omega)-nitro-L-arginine-2,4-L-diaminobutyric amide (N(omega), 10 mM) was delivered by intradermal microdialysis, cutaneous vascular conductance (CVC) decreased by an amount equivalent to the largest reduction produced by the nonselective NO synthase (NOS) inhibitor nitro-L-arginine (NLA, 10 mM). We demonstrated that the response to ACh was minimally attenuated by nNOS blockade using N(omega) but markedly attenuated by NLA, indicating that eNO largely comprises the receptor-mediated NO release by ACh. We further demonstrated that the ACh dose response was minimally reduced, whereas local heat-mediated NO-dependent responses were markedly reduced in POTS compared with control subjects. This is consistent with intact endothelial function and reduced NO of neuronal origin in POTS. The local heating response was highly attenuated in POTS [60 +/- 6 percent maximum CVC(%CVC(max))] compared with…
How strong is the evidence?
Evidence Hub reads this as a case-control, done in people. Its evidence level is 4 of 5 (Low · observational). Observational designs can show an association but not prove cause.
Read the paper
Related studies
- eggNOG 5.0: a hierarchical, functionally and phylogenetically annotated orthology resource based on 5090 organisms and 2502 viruses
- Online Survival Analysis Software to Assess the Prognostic Value of Biomarkers Using Transcriptomic Data in Non-Small-Cell Lung Cancer
- OptiType: precision HLA typing from next-generation sequencing data
- Nicotinic Cholinergic System and COVID-19: In Silico Identification of an Interaction between SARS-CoV-2 and Nicotinic Receptors with Potential Therapeutic Targeting Implications
- Saccharomyces cerevisiae cells have three Omega class glutathione S-transferases acting as 1-Cys thiol transferases
- Hemolysis at low blood flow rates: in-vitro and in-silico evaluation of a centrifugal blood pump
Go deeper in Evidence Hub
Evidence Hub adds a study data sheet (design, sample size, evidence level, key numbers), an AI summary and a chat grounded in the paper's text.