title: Cystathionine gamma-lyase of perivascular adipose tissue with reversed regulatory effect in diabetic rat artery.
abstract: The aim of this study is to reveal the regulatory role of cystathionine gamma-lyase (CSE), the main source of hydrogen sulphide (H2S) in perivascular adipose tissue (PVAT), of diabetic rats. Diabetes was induced in male rats by a single intraperitoneal injection of streptozotocin. Animals with glucose levels above 20 mmol/L were determined as diabetic. The rat gracilis arteries (a. gracilis) were dissected with or without PVAT. In allin vitroexperiments endothelium-denuded preparations were used for isometric contraction measurements. Increasing concentrations of 5-hydroxytryptamine (5-HT) from 10-10to 10-5mol/L were applied to induce gradual increase in force of contractions of circular artery segments. The relaxing effect of CSE was inhibited by DL-propargyl glycine (PGG). The presence of PVAT decreases the contractile response to 5-HT of a. gracilis from control rats. This response is reversed in contraction studies in the same rat artery from diabetic rats. DL-PPG (1 mmol/L) induced significant increase of the force of contraction in artery preparations with PVAT from control rats in the whole range of 5-HT. In contrast, PGG had a relaxing effect in high concentrations of 5-HT (10-6and 10-5mol/L) in diabetic rat arteries with PVAT. It is concluded that in skeletal muscle artery from diabetic rats, a mediator related to H2S is released from PVAT. This paracrine mediator increases the maximal force of contraction of endothelium-denuded preparations at higher concentrations of 5-HT.
authors.affiliation: Department of Animal and Human Physiology, Faculty of Biology, Sofia University St. Kliment Ohridski , Sofia , Bulgaria.
authors.forename: Radoslava
authors.initials: R
authors.lastname: Emilova
authors.affiliation: Department of Excitable Structures, Institute of Biophysics and Biomedical Engineering, Bulgarian Academy of Sciences , Sofia , Bulgaria.
authors.forename: Daniela
authors.initials: D
authors.lastname: Dimitrova
authors.affiliation: Institute of Biology, Faculty of Natural Sciences and Mathematics, University of Skopje Sts. Cyril and Methodius , Skopje , Macedonia.
authors.forename: Mitko
authors.initials: M
authors.lastname: Mladenov
authors.affiliation: Department of Immunobiology of Reproduction, Institute of Biology and Immunology of Reproduction, Bulgarian Academy of Sciences , Sofia , Bulgaria.
authors.forename: Teodora
authors.initials: T
authors.lastname: Daneva
authors.affiliation: Centre for Biomedicine and Medical Technology, Cardiovascular Physiology, Medical Faculty Mannheim, Ruprecht-Karls-University Heidelberg , Mannheim , Germany.
authors.forename: Rudolf
authors.initials: R
authors.lastname: Schubert
authors.affiliation: Department of Animal and Human Physiology, Faculty of Biology, Sofia University St. Kliment Ohridski , Sofia , Bulgaria.
authors.forename: Hristo
authors.initials: H
authors.lastname: Gagov
keywords: 5-hydroxytryptamine (serotonin); arterial contraction; diabetes; hydrogen sulphide; vascular dysfunction