Effect of insulin and prolactin on acyltransferase activities in MAC-T bovine mammary cells.
The enzymatic activities of sn-glycerol-3-phosphate acyltransferase and lysophosphatidate acyltransferase were investigated in microsomal fractions prepared from MAC-T cells from bovine mammary gland and from FTO-2B cells from rat liver. In both cell lines, sn-glycerol-3-phosphate acyltransferase exhibited similar rates of palmitate and oleate incorporation. However, lysophosphatidate acyltransferase activity in MAC-T cells had a 2.8-fold greater rate of palmitate incorporation than of oleate incorporation. In FTO-2B cells, there was a 1.4-fold greater rate of oleate incorporation than of palmitate incorporation. FTO-2B and MAC-T cells displayed acyltransferase activities that were consistent with liver and mammary tissues, respectively. The acyltransferases were examined from FTO-2B and MAC-T cells that were treated with insulin and prolactin. Insulin suppressed both acyltransferase activities in FTO-2B cells, and prolactin had a stimulatory effect; however, these effects were very small. In contrast, insulin and prolactin had a stimulatory effect on both acyltransferase activities in MAC-T cells; prolactin elicited the largest effect. Treatment of MAC-T cells with cycloheximide inhibited the stimulatory effect of prolactin on acyltransferase activities.
Morand
L Z
LZ
Department of Food Science and Technology, University of California, Davis 95616, USA.
Morand
J N
JN
Matson
R
R
German
J B
JB
D000217:Acyltransferases / Q000378:metabolism*; D000818:Animals; D002417:Cattle; D002460:Cell Line; D005260:Female; D005992:Glycerol-3-Phosphate O-Acyltransferase / Q000378:metabolism*; D007328:Insulin / Q000494:pharmacology*; D007774:Lactation; D008321:Mammary Glands, Animal / Q000187:drug effects / Q000201:enzymology* / Q000648:ultrastructure; D008861:Microsomes / Q000201:enzymology; D008862:Microsomes, Liver / Q000187:drug effects / Q000201:enzymology; D009245:NADH Dehydrogenase / Q000378:metabolism; D009249:NADP / Q000494:pharmacology; D010171:Palmitoyl Coenzyme A / Q000378:metabolism; D011388:Prolactin / Q000494:pharmacology*; D051381:Rats
D007328:Insulin; D010171:Palmitoyl Coenzyme A; D009249:NADP; D011388:Prolactin; D009245:NADH Dehydrogenase; D000217:Acyltransferases; D005992:Glycerol-3-Phosphate O-Acyltransferase; C018764:2-acylglycerophosphate acyltransferase