King Saud University Repository >
King Saud University >
Health Colleges >
College of Pharmacy >
College of Pharmacy >
Please use this identifier to cite or link to this item:
|Title: ||Melatonin inhibits the contractile effect of vanadate in the isolated pulmonary arterial rings of rats: possible role of hydrogen peroxide|
|Authors: ||Nagi, Mahmoud N.|
Mansour, Mahmoud A.
Al-shabanah, Othman A.
El-Kashef, Hassan A.
Pulmonary arterial rings
|Issue Date: ||2002 |
|Citation: ||Journal of Biochemical and Molecular Toxicology:
|Abstract: ||The effect and possible mechanism of action
of vanadate on the isolated pulmonary arterial
rings of normal rats were studied. Pulmonary arterial
rings contracted in response to vanadate (0.1–1 mM)
in a concentration-dependent manner. Preincubation
of the pulmonary arterial rings with 1 mM melatonin
significantly reduced the contractile effect of vanadate
by more than 60%. Furthermore, addition of hydrogen
peroxide (50 M) or enzymatic generation of hydrogen
peroxide by the addition of glucose oxidase
(10 U/mL) to the medium containing glucose produced
remarkable increases in the pulmonary arterial tension,
46.2±7.3 and 78.7±9.7 g tension/g tissue, respectively.
Similarly, incubation of the pulmonary arterial
rings with 1 mM melatonin significantly reduced the
contractile responses of the arterial rings to hydrogen
peroxide and glucose/glucose oxidase to 25.7±2.9 and
24.7±4.4 g tension/g tissue, respectively. Vanadate, in
vitro, significantly stimulated the oxidation of NADH
by xanthine oxidase, and the rate of oxidation was increased
by increasing either time or vanadate concentration.
Similarly, addition of melatonin to a reaction
mixture containing xanthine oxidase and vanadate significantly
inhibited the rate of NADH oxidation in a
concentration-dependent fashion. The results of the
present study indicated that vanadate induced contraction
in the isolated pulmonary arterial rings, which was
significantly reduced by melatonin. Furthermore, the
contractile effect of vanadate on the pulmonary arterial
rings may be attributed to the intracellular generation
of hydrogen peroxide.|
|Description: ||Department of Pharmacology, College of Pharmacy, King Saud University, P.O. Box 2457, Riyadh, 11451, Saudi Arabia;
|ISSN: ||Print: 1095-6670, Online: 1099-0461|
|Appears in Collections:||College of Pharmacy|
Items in DSpace are protected by copyright, with all rights reserved, unless otherwise indicated.