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Lintault, Laura

Animal Science

2005

M.S.

Pregnant rats subjected to hypergravity have decreased rates of mammary metabolism and reduced food intake. We hypothesized that liver and adipose metabolism would not change due to 2-g, but may change due to energy balance. The effects of hypergravity on mammary, liver and adipose tissue metabolism were measured in periparturient rats centrifuged at 2.0-g (hypergravity; n=l 8) or kept at 1.0-g (control; n=18), until gestation d 21 (G21) or postpartum d 3 (P3). 18 rats were fed to match the intake of the hypergravity group (pair-fed). Energy and nitrogen balance ofhypergravity and pair-fed dams were less than control (P<0.05). Percent body fat of hypergravity dams was less than control (P<0.001) and pair-fed (P<0.1). At G21, glucose oxidation to CO₂ (GLUOX) and glucose incorporation into lipids (GLULIPID) in mammary were less in hypergravity than control and pair-fed. In adipose, glucose metabolism was less in hypergravity than control and pair-fed (GLUOX: 44, 93 and 118 nmol/100mg/h; GLULIPID: 8, 35 and 68 nmol/100mg/h; P<0.05). Liver GLULIPID was greater in hypergravity than control and pair-fed (3.23, 1.20 and 0.54 nmol/100mg/h; P<0.01). At P3, adipose lipolysis was less in hypergravity than control and pair-fed (765, 1236 and 1125 moles glycerol/million adipocytes/h; P=0.05). GLULIPID in liver was greater in control than hypergravity and pair-fed (P<0.05). Despite the fact that energy and nitrogen balance were the same in hypergravity and pair-fed pregnant rats, glucose metabolism in key tissues was markedly altered by hypergravity. Therefore the changes observed in hypergravity exposed rats can not be accounted for by reduced food intake.