geoscience.net logo
+ Resolve Article
+ Follow Us
Follow on FacebookFollow on Facebook
Follow on TwitterFollow on Twitter

+ Translate
+ Subscribe to Site Feed
GeoScience Most Shared ContentMost Shared Content

Effects of neuronal nitric oxide synthase on human coronary artery diameter and blood flow in vivo


, : Effects of neuronal nitric oxide synthase on human coronary artery diameter and blood flow in vivo. Circulation 119(20): 2656-2662

Nitric oxide (NO)-mediated local regulation of vascular tone is considered to involve endothelial NO synthase (eNOS). However, we recently reported that human forearm basal microvascular tone in vivo is tonically regulated by neuronal NO synthase (nNOS), in contrast to an acetylcholine-stimulated reduction in tone, which is eNOS dependent. Here, we investigated the in vivo effects of an nNOS-selective inhibitor, S-methyl-L-thiocitrulline (SMTC), on the human coronary circulation and on flow-mediated dilatation in the forearm. In patients with angiographically normal coronary arteries, intracoronary infusion of SMTC (0.625 micromol/min) reduced basal coronary blood flow by 34.1+/-5.2% (n=10; P<0.01) and epicardial coronary diameter by 3.6+/-1.2% (P=0.02) but had no effect on increases in flow evoked by intracoronary substance P (20 pmol/min). The nonselective NOS inhibitor N(G)-monomethyl-L-arginine (25 micromol/min) also reduced basal coronary flow (by 22.3+/-5.3%; n=8; P<0.01) but, in contrast to SMTC, inhibited substance P-induced increases in flow (P<0.01). In healthy volunteers, local infusion of SMTC (0.2 micromol/min) reduced radial artery blood flow by 36.0+/-6.4% (n=10; P=0.03) but did not affect flow-mediated dilatation (P=0.55). In contrast, N(G)-monomethyl-L-arginine (2 micromol/min) infusion reduced radial blood flow to a similar degree (by 39.7+/-11.8%; P=0.02) but also inhibited flow-mediated dilatation by approximately 80% (P<0.01). These data indicate that local nNOS-derived NO regulates basal blood flow in the human coronary vascular bed, whereas substance P-stimulated vasodilatation is eNOS mediated. Thus, nNOS and eNOS have distinct local roles in the physiological regulation of human coronary vascular tone in vivo.

US$19.90

PMID: 19433760

DOI: 10.1161/CIRCULATIONAHA.108.822205


Other references

Numata, Osamu, 1997: Cytokinesis in Tetrahymena Division plane determination and contractile ring formation. Cell Structure & Function 22(6): 644, Dec

Balasubramanian, M.; Spencer, A.J.; Short, S.D.; Watkins, K.; Chrisopoulos, S.; Brennan, D.S., 2017: Development of life story experience (LSE) scales for migrant dentists in Australia: a sequential qualitative-quantitative study. The integration of qualitative and quantitative approaches introduces new avenues to bridge strengths, and address weaknesses of both methods. To develop measure(s) for migrant dentist experiences in Australia through a mixed methods approach. The...

Löscher, W.; Gillard, M.; Sands, Z.A.; Kaminski, R.M.; Klitgaard, H., 2016: Synaptic Vesicle Glycoprotein 2A Ligands in the Treatment of Epilepsy and Beyond. NlmCategory="UNASSIGNED">The synaptic vesicle glycoprotein SV2A belongs to the major facilitator superfamily (MFS) of transporters and is an integral constituent of synaptic vesicle membranes. SV2A has been demonstrated to be involved...

Parisi, A.; Filice, G., 2002: Transverse myelitis associated with Mycoplasma pneumoniae pneumonitis: a report of two cases. The authors report two cases of transverse myelitis due to Mycoplasma pneumoniae occurring during a recent acute infection due to Epstein-Barr virus (EBV). The clinical picture included weakness of the legs, bladder dysfunction, fever, headache an...

Audisio, P., 1978: Nota tassonomica su Thalycra emmanueli Auroux (Col. Nitidulidae). The validity of T. emmanueli (Coleoptera, Nitidulidae) is confirmed. The 2nd Iberian Spain and Portugal and European species of the genus were presented.

Gics, P.W., 1999: Food package including a tray with cover member having a raised top surface. Official Gazette of the United States Patent & Trademark Office Patents 1220(5): 4468, March 30

Wang, Q.Jie.; Zhang, Y.; Soh, Y.Chai., 2006: Design of linear-phase two-port optical interleavers using lattice architectures. A novel lattice structure for the design of two-port optical interleavers is presented. With the proposed lattice structure, the exact linear-phase characteristics of the two outputs of interleavers are guaranteed. The desired spectral characteris...

Garg, S.; Bal, V.; Rath, S.; George, A., 1999: Effect of multiple antigenic exposures in the gut on oral tolerance and induction of antibacterial systemic immunity. Oral tolerance of microbial antigens was analysed in an experimental model in which mice were treated orally with a single small dose of soluble antigen and challenged systemically with the antigen in complete Freund's adjuvant. Whereas oral...

Morris, J.; Fleming, R.; Semenenko, I., 2001: The feasibility of establishing a small scale manure processing plant. Canadian Journal of Animal Science 81(4): 620, December

Gunasekaran, K.; Tsai, C-Jung.; Kumar, S.; Zanuy, D.; Nussinov, R., 2003: Extended disordered proteins: targeting function with less scaffold. It has been estimated that a large fraction of cellular proteins are natively disordered. Current opinion largely holds that natively disordered proteins are more 'adaptive', leading to advantages in regulation and in binding diverse lig...