Suppressive role of endogenous regucalcin in the enhancement of nitric oxide synthase activity in liver cytosol of normal and regucalcin transgenic rats
- 6 March 2003
- journal article
- research article
- Published by Wiley in Journal of Cellular Biochemistry
- Vol. 88 (6), 1226-1234
- https://doi.org/10.1002/jcb.10452
Abstract
The suppressive role of endogenous regucalcin, which is a regulatory protein of calcium signaling, in the enhancement of nitric oxide (NO) synthase activity in the liver cytosol of rats was investigated. The enzyme activity was measured in a reaction mixture containing either vehicle or calcium chloride (1–20 μM) in the absence or presence of regucalcin (0.1, 0.25, or 0.5 μM). NO synthase activity was significantly increased by the addition of calcium (5–20 μM). This increase was completely abolished in the presence of trifluoperazine (TFP; 10–50 μM), an antagonist of Ca2+/calmodulin. The addition of regucalcin (0.1–0.5 μM) caused a significant fall in the calcium-increased enzyme activity. The effect of regucalcin (0.25 μM) in decreasing NO synthase activity was seen in the presence of ethylene glycol bis-(2-aminoethylether) N,N,N′,N′-tetraacetic acid (EGTA, 1 mM) or TFP (20 μM), indicating that regucalcin acts independent on Ca2+/calmodulin. NO synthase activity was significantly raised in the presence of anti-regucalcin monoclonal antibody (10–50 ng/ml) in the reaction mixture. The effect of the antibody (50 ng/ml) or calcium (10 μM) in elevating NO synthase activity in the liver cytosol of normal rats was not seen in the liver cytosol obtained from regucalcin transgenic rats. Moreover, the increase in NO synthase activity in the liver cytosol of normal rats induced by a single intraperitoneal administration of calcium (5.0 mg/100 g body weight) was significantly enhanced in the presence of anti-regucalcin monoclonal antibody (50 ng/ml) in the reaction mixture. The administration of calcium caused a significant increase in regucalcin level in the liver cytosol of normal rats. The present study demonstrated that endogenous regucalcin plays a suppressive role in the enhancement of NO synthase activity in the liver cytosol of rats. J. Cell. Biochem. 88: 1226–1234, 2003.Keywords
This publication has 35 references indexed in Scilit:
- Suppressive role of endogenous regucalcin in the enhancement of deoxyribonucleic acid synthesis activity in the nucleus of regenerating rat liverJournal of Cellular Biochemistry, 2002
- Role of endogenous regucalcin in transgenic rats: Suppression of kidney cortex cytosolic protein phosphatase activity and enhancement of heart muscle microsomal Ca2+‐ATPase activityJournal of Cellular Biochemistry, 2002
- The Role of Regucalcin in Nuclear Regulation of Regenerating LiverBiochemical and Biophysical Research Communications, 2000
- Enhancement of neutral phosphatase activity in the cytosol and nuclei of regenerating rat liver: Role of endogenous regucalcinJournal of Cellular Biochemistry, 1999
- Molecular cloning and sequencing of the cDNA coding for a calcium‐binding protein regucalcin from rat liverFEBS Letters, 1993
- Calcium administration stimulates the expression of calcium‐binding protein regucalcin mRNA in rat liverFEBS Letters, 1992
- Calcium-binding protein regucalcin is an activator of (Ca2+-Mg2+)-adenosine triphosphatase in the plasma membranes of rat liver.CHEMICAL & PHARMACEUTICAL BULLETIN, 1987
- Role of calcium in the hormonal regulation of liver metabolismBiochimica et Biophysica Acta (BBA) - Reviews on Bioenergetics, 1981
- Purification of calcium binding substance from soluble fraction of normal rat liver.CHEMICAL & PHARMACEUTICAL BULLETIN, 1978
- Cleavage of Structural Proteins during the Assembly of the Head of Bacteriophage T4Nature, 1970