Enhanced utilization of glycerol for glyceride synthesis in isolated adipocytes from early pregnant rats.
Adipose tissue normally has low glycerol kinase activity, but its expression is enhanced under conditions of augmented insulin sensitivity and/or obesity. Since these conditions occur during early pregnancy, the comparative utilization of glucose or glycerol by isolated adipocytes from rats at 0, 7, 14, or 20 days of pregnancy was studied. Incubations were carried out in the presence of [U(14)C]-glucose or -glycerol in medium supplemented or not with 5 mM glucose and 100 nM insulin. The conversion of glucose into esterified fatty acids and glyceride glycerol was greatest in adipocytes from 7-day pregnant rats, the effect being further enhanced by insulin. Both the amount of aquoporin 7 and the in vitro conversion of glycerol into glyceride glycerol were greatest in adipocytes of 7-day pregnant rats, the later being unaltered by insulin. In the presence of glucose, the overall glycerol utilization was lower than in its absence and glycerol conversion into glyceride glycerol was further decreased by insulin, the effect only being significant in adipocytes from 7-day pregnant rats. It is proposed that the enhanced utilization of glycerol for glyceride glycerol synthesis in adipose tissue contributes to the net accumulation of fat depots that normally takes place in early pregnancy.
Herrera
Emilio
E
Faculties of Pharmacy and Medicine, Department of Biology, Universidad CEU San Pablo, Ctra. Boadilla del Monte km 5.300, Madrid, Spain. eherrera@ceu.es
del Campo
Sonia
S
Marciniak
Justyna
J
Sevillano
Julio
J
Ramos
Maria Pilar
MP
D017667:Adipocytes / Q000378:metabolism*; D000273:Adipose Tissue / Q000378:metabolism; D000818:Animals; D020346:Aquaporins / Q000378:metabolism; D005260:Female; D005947:Glucose / Q000378:metabolism*; D051275:Glucose Transporter Type 4 / Q000378:metabolism; D005989:Glycerides / Q000096:biosynthesis*; D005990:Glycerol / Q000378:metabolism*; D007328:Insulin / Q000502:physiology; D011247:Pregnancy / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley
C491926:Aqp7 protein, rat; D020346:Aquaporins; D051275:Glucose Transporter Type 4; D005989:Glycerides; D007328:Insulin; C495694:Slc2a4 protein, rat; D005947:Glucose; D005990:Glycerol