Elevated Vascular Level of ortho-Tyrosine Contributes to the Impairment of Insulin-Induced Arterial Relaxation
| Autor: | Boglárka Laczy, Gergő A. Molnár, István András Szijártó, István Wittmann, Katalin Böddi, Esztella Mikolás, Judit Cseh, Anikó Takátsy, A. Koller, Tibor Kovács, Viktória Fisi, Maik Gollasch |
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| Rok vydání: | 2014 |
| Předmět: |
Male
medicine.medical_specialty Nitric Oxide Synthase Type III Endocrinology Diabetes and Metabolism medicine.medical_treatment Clinical Biochemistry Administration Oral In Vitro Techniques Biochemistry Rats Sprague-Dawley Mice Endocrinology Enos Internal medicine Diabetes mellitus medicine Animals Insulin Phosphorylation Tyrosine Cells Cultured chemistry.chemical_classification biology Vasomotor Electrical impedance myography business.industry Biochemistry (medical) Endothelial Cells General Medicine medicine.disease biology.organism_classification Amino acid Femoral Artery Vasodilation chemistry Endothelium Vascular business |
| Zdroj: | Hormone and Metabolic Research. 46:749-752 |
| ISSN: | 1439-4286 0018-5043 |
| Popis: | studies have shown that in diabetes mellitus, insulin-induced relaxation of arteries is impaired and the level of ortho -tyrosine ( o -Tyr), an oxidized amino acid is increased. Thus, we hypothesized that elevated vascular level of o -Tyr contributes to the impairment of insulin-induced vascular relaxation. Rats were fed with o -Tyr for 4 weeks. Insulin-induced vasomotor responses of isolated femoral artery were studied using wire myography. Vascular o -Tyr content was meas- ured by HPLC, whereas immunoblot analyses were preformed to detect eNOS phosphorylation. Sustained oral supplementation of rats with o - Tyr increased the content of o -Tyr in the arterial wall and signifi cantly reduced the relaxations to insulin. Sustained supplementation of cultured endothelial cells with o -Tyr increased the incor- poration of o -Tyr and mitigated eNOS Ser (1 177) phosphorylation to insulin. Increasing arterial wall o -Tyr level attenuates insulin-induced relax- ation - at least in part - by decreasing eNOS acti- vation. Elevated level of o -Tyr could be an underlying mechanism for vasomotor dysfunc- tion in diabetes mellitus. Supporting Information for this article is available online at http://www.thieme-connect. |
| Databáze: | OpenAIRE |
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