Tags

Type your tag names separated by a space and hit enter

Up-regulation of nNOS and associated increase in nitrergic vasodilation in superior mesenteric arteries in pre-hepatic portal hypertension.
J Hepatol. 2005 Aug; 43(2):258-65.JH

Abstract

BACKGROUND/AIMS

Splanchnic arterial vasodilation in portal hypertension has been attributed largely to vascular NO overproduction. Three NO-synthase (NOS) isoforms have been identified of which e(ndothelial)-NOS has been found up-regulated and i(nducible)-NOS not expressed in the splanchnic circulation in portal hypertension. So far, n(euronal)-NOS has not been investigated and hence, the current study evaluates nNOS-expression and nNOS-mediated vasorelaxation in a model of portal vein-ligated rats (PVL).

METHODS

Mesenteric vasculature of PVL and sham rats was evaluated for nNOS-protein (immunohistochemically and Western blotting). In vitro perfused de-endothelialized mesenteric arterial vasculature was pre-constricted with norepinephrine (EC(80)) and tested for nNOS-mediated vasorelaxation by periarterial nerve stimulation (PNS, 2-12 Hz, 45V) before and after incubation with the NOS-inhibitor L-NAME (10(-4)M).

RESULTS

nNOS was localized to the adventitia of the mesenteric arterial tree showing more intense staining and increased protein expression in PVL as compared to sham rats. PNS induced a frequency-dependent vasorelaxation, which was more pronounced in PVL rats. L-NAME abolished this difference in nerval-mediated vasorelaxation, the effect being significantly greater in PVL than in sham animals.

CONCLUSIONS

Perivascular nNOS-protein expression is enhanced in mesenteric arteries in portal hypertension mediating an increased nerval NO-mediated vasorelaxation. This nNOS-derived NO overproduction may play an important role in the pathogenesis of arterial vasodilation in portal hypertension.

Authors+Show Affiliations

Department of Internal Medicine, University School of Medicine, 93042 Regensburg, Germany.No affiliation info availableNo affiliation info availableNo affiliation info availableNo affiliation info available

Pub Type(s)

Comparative Study
Journal Article
Research Support, Non-U.S. Gov't

Language

eng

PubMed ID

15963596

Citation

Jurzik, Lars, et al. "Up-regulation of nNOS and Associated Increase in Nitrergic Vasodilation in Superior Mesenteric Arteries in Pre-hepatic Portal Hypertension." Journal of Hepatology, vol. 43, no. 2, 2005, pp. 258-65.
Jurzik L, Froh M, Straub RH, et al. Up-regulation of nNOS and associated increase in nitrergic vasodilation in superior mesenteric arteries in pre-hepatic portal hypertension. J Hepatol. 2005;43(2):258-65.
Jurzik, L., Froh, M., Straub, R. H., Schölmerich, J., & Wiest, R. (2005). Up-regulation of nNOS and associated increase in nitrergic vasodilation in superior mesenteric arteries in pre-hepatic portal hypertension. Journal of Hepatology, 43(2), 258-65.
Jurzik L, et al. Up-regulation of nNOS and Associated Increase in Nitrergic Vasodilation in Superior Mesenteric Arteries in Pre-hepatic Portal Hypertension. J Hepatol. 2005;43(2):258-65. PubMed PMID: 15963596.
* Article titles in AMA citation format should be in sentence-case
TY - JOUR T1 - Up-regulation of nNOS and associated increase in nitrergic vasodilation in superior mesenteric arteries in pre-hepatic portal hypertension. AU - Jurzik,Lars, AU - Froh,Matthias, AU - Straub,Rainer H, AU - Schölmerich,Jürgen, AU - Wiest,Reiner, PY - 2004/05/12/received PY - 2005/02/03/revised PY - 2005/02/16/accepted PY - 2005/6/21/pubmed PY - 2005/11/15/medline PY - 2005/6/21/entrez SP - 258 EP - 65 JF - Journal of hepatology JO - J Hepatol VL - 43 IS - 2 N2 - BACKGROUND/AIMS: Splanchnic arterial vasodilation in portal hypertension has been attributed largely to vascular NO overproduction. Three NO-synthase (NOS) isoforms have been identified of which e(ndothelial)-NOS has been found up-regulated and i(nducible)-NOS not expressed in the splanchnic circulation in portal hypertension. So far, n(euronal)-NOS has not been investigated and hence, the current study evaluates nNOS-expression and nNOS-mediated vasorelaxation in a model of portal vein-ligated rats (PVL). METHODS: Mesenteric vasculature of PVL and sham rats was evaluated for nNOS-protein (immunohistochemically and Western blotting). In vitro perfused de-endothelialized mesenteric arterial vasculature was pre-constricted with norepinephrine (EC(80)) and tested for nNOS-mediated vasorelaxation by periarterial nerve stimulation (PNS, 2-12 Hz, 45V) before and after incubation with the NOS-inhibitor L-NAME (10(-4)M). RESULTS: nNOS was localized to the adventitia of the mesenteric arterial tree showing more intense staining and increased protein expression in PVL as compared to sham rats. PNS induced a frequency-dependent vasorelaxation, which was more pronounced in PVL rats. L-NAME abolished this difference in nerval-mediated vasorelaxation, the effect being significantly greater in PVL than in sham animals. CONCLUSIONS: Perivascular nNOS-protein expression is enhanced in mesenteric arteries in portal hypertension mediating an increased nerval NO-mediated vasorelaxation. This nNOS-derived NO overproduction may play an important role in the pathogenesis of arterial vasodilation in portal hypertension. SN - 0168-8278 UR - https://www.unboundmedicine.com/medline/citation/15963596/Up_regulation_of_nNOS_and_associated_increase_in_nitrergic_vasodilation_in_superior_mesenteric_arteries_in_pre_hepatic_portal_hypertension_ L2 - https://linkinghub.elsevier.com/retrieve/pii/S0168-8278(05)00260-6 DB - PRIME DP - Unbound Medicine ER -