Korean J Gastroenterol.  2000 Mar;35(3):283-290.

Role of Protein Kinase in Spontaneous Phasic Contraction of Cat Gastric Smooth Muscle

• Sim SS
• Choi JC
• Kim MS
• Kim CJ
• Jo YH

Abstract

Gastric muscle contraction is known to be regulated by complicated mechanism. In the present study, the role of protein kinase in the modulation of spontaneous gastric phasic contraction was investigated.
METHODS
Circular muscle strips (2.0x0.2 cm) were prepared from the corpus of cat stomach to measure isometric contraction, and the contraction was recorded in a cylindrical chamber filled with Krebs-Ringer solution (pH 7.4, temperature 36C degrees) bubbled with 5% CO2 in O2.
RESULTS
The amplitude and frequency of spontaneous phasic contraction were significantly inhibited by protein kinase C (PKC) inhibitor and tyrosine kinase (TK) inhibitor, but not by calmodulin antagonist. The combined effect of bisindolymaleimide (a PKC inhibitor) and genistein (a TK inhibitor) was more potent than that of each one. On the other hand, forskolin (an adenylyl cyclase activator) and sodium nitroprusside (a guanylyl cyclase activator) inhibited dose- dependently the amplitude and frequency of spontaneous phasic contraction.
CONCLUSIONS
From the above results, it is suggested that both PKC and TK play a stimulatory role in the modulation of spontaneous phasic contraction, whereas cAMP- and cGMP-dependent protein kinase have an inhibitory effect.

Keyword

Phasic contraction; Protein kinase C; Tyrosine kinase; Cyclic nucleotide; Calmodulin antagonist

MeSH Terms

Adenylyl Cyclases
Animals
Calmodulin
Cats*
Colforsin
Genistein
Guanylate Cyclase
Hand
Isometric Contraction
Muscle Contraction
Muscle, Smooth*
Nitroprusside
Protein Kinase C
Protein Kinases*
Protein-Tyrosine Kinases
Stomach
Calmodulin
Colforsin
Genistein
Guanylate Cyclase
Nitroprusside
Protein Kinase C
Protein Kinases
Protein-Tyrosine Kinases