The Ca2+-transporting activity of rat liver microsomes in response to protein undernutrition: implications for liver tumor promotion.
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 P450 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.
Adenuga
G A
GA
Department of Biochemistry, Ogun State University, Ago-Iwoye, Nigeria.
D000818:Animals; D002118:Calcium / Q000378:metabolism*; D004032:Diet; D017136:Ion Transport; D008113:Liver Neoplasms / Q000209:etiology / Q000378:metabolism; D008297:Male; D008862:Microsomes, Liver / Q000378:metabolism*; D011506:Proteins / Q000008:administration & dosage* / Q000378:metabolism; D051381:Rats; D011916:Rats, Inbred F344
D011506:Proteins; D002118:Calcium