The Ca2+-transporting activity of rat liver microsomes in response to protein undernutrition: Implications for liver tumor promotion

摘要

The effect of protein undernutrition on the activity of the smooth endoplasmic reticulum (microsomal) Ca2+ ATPase (SERCA) was investigated. After 12 weeks of ad libitum ingestion of low protein diet (5% protein), a significant depression (p<0.05) of liver ER Ca2+ ATPase activity (68.6% depression) was observed. However, no significant effects on cytochrome P-450 activity and relative liver weight were found. It is proposed that low protein diet by inhibiting the rat liver SERCA activity, might increase the cytosolic free calcium ion concentration ([Ca2+]) and promote the development of liver tumor. The possible mechanisms of low protein diet induced inhibition of SERCA activity are highlighted. [References: 33]