Korean J Gastroenterol.  1999 Jan;33(1):1-10.

Effects of Vanadate and Pervanadate on Contraction of Cat Gastric Smooth Muscle

• Sim SS
• Choi HB
• Shim HS
• Rhie DJ
• Hahn SJ
• Yoon SH
• Kim MS
• Jo YH

Abstract

BACKGROUND/AIMS: Activated mammalian cells produce the reactive oxygen species from oxygen and they convert vanadate into pervanadate. The aim of the present study was to compare the contactile mechanisms of vanadate and pervanadate in the gastric smooth muscle of cat.
METHODS
Muscle strips were isolated from the fundus of cat stomach to measure isometric contraction. Muscle cells were prepared to measure the activity of protein kinase C (PKC) and the level of protein tyrosine phosphorylation.
RESULTS
Both vanadate and pervanadate caused contractions of smooth muscle and the contraction induced by pervanadate was greater than that induced by vanadate. These contractions depended on the extracellular Ca2+ and the influx of extracellular Ca2+ occurred through voltage-dependent Ca2+ channel. Protein kinase antagonist inhibited the vanadate-induced contraction. However, the inhibitory effect of H-7 was smaller in pervanadate-induced contraction. Both vanadate and pervanadate had no effect on the activity of phospholipase C, but pervanadate significantly increased protein tyrosine phosphorylation.
CONCLUSIONS
The contraction induced by vanadate or pervanadate may depend on the influx of extracellular Ca2+ via voltage-dependent Ca2+ channel Vanadate seems to be more dependent on protein kinase C. The difference of contraction mechanism by these elements may be related to the differences in the level of protein tyrosine phosphorylation.

Keyword

Phospholipase C; Protein kinase C; Smooth muscle contraction; Tyrosine phosphory lation; Vanadate

MeSH Terms

1-(5-Isoquinolinesulfonyl)-2-Methylpiperazine
Animals
Cats*
Isometric Contraction
Muscle Cells
Muscle, Smooth*
Oxygen
Phosphorylation
Protein Kinase C
Protein Kinases
Reactive Oxygen Species
Stomach
Type C Phospholipases
Tyrosine
Vanadates*
1-(5-Isoquinolinesulfonyl)-2-Methylpiperazine
Oxygen
Protein Kinase C
Protein Kinases
Reactive Oxygen Species
Type C Phospholipases
Tyrosine
Vanadates