scholarly journals Evidence for a role of insulin in the regulation of lipogenesis in lactating rat mammary gland. Measurements of lipogenesis in vivo and plasma hormone concentrations in response to starvation and refeeding

1978 ◽  
Vol 176 (1) ◽  
pp. 343-346 ◽  
Author(s):  
A M Robinson ◽  
J R Girard ◽  
D H Williamson
Keyword(s):  
Mammary Gland ◽  
Fatty Acid ◽  
Fatty Acid Synthesis ◽  
Plasma Insulin ◽  
Acid Synthesis ◽  
Plasma Insulin Concentration ◽  
Rat Mammary Gland ◽  
Plasma Hormone

Fatty acid synthesis in the mammary gland of lactating rats in vivo was 5-fold higher than in the liver. Starvation decreased fatty acid synthesis in the gland 50-fold, whereas refeeding for 2h completely reversed this change. The plasma insulin concentration decreased 2-fold in starvation and was restored to the fed-rat value on refeeding. Glucagon and prolactin concentrations did not always change in parallel with lipogenesis, suggesting that insulin may be a regulator of this process in the gland.

Energy balance in adrenalectomized ob/ob mice: effects of dietary starch and glucose

1988 ◽  
Vol 255 (1) ◽  
pp. R141-R148 ◽  
Author(s):  
B. P. Warwick ◽  
D. R. Romsos
Keyword(s):  
Fatty Acid ◽  
Energy Balance ◽  
Wheat Bran ◽  
Fatty Acid Synthesis ◽  
Plasma Insulin ◽  
Acid Synthesis ◽  
Energetic Efficiency ◽  
Simple Sugar ◽  
Dietary Starch

Effects of different carbohydrate types on energy balance, fatty acid synthesis, and plasma insulin concentrations in adrenalectomized ob/ob mice were investigated. Obese (ob/ob) and lean mice adrenalectomized at 4 wk of age received one of four high-carbohydrate powdered diets for 3 wk: stock, glucose, starch, or starch plus wheat bran. Adrenalectomy reduced energy intake of ob/ob mice equally independent of diet type, whereas energetic efficiency, in vivo rates of fatty acid synthesis in liver and white adipose tissue, and plasma insulin concentrations were substantially reduced to approach values in lean mice in all adrenalectomized ob/ob mice except those fed glucose. The ability of adrenalectomy to normalize energy balance in ob/ob mice depends on factors other than the reduced circulating concentration of glucocorticoids alone. Diet composition is a crucial factor, and striking differences exist between semipurified diets containing a simple sugar (glucose) and those containing a complex carbohydrate (starch), with no additional effect of dietary fiber (wheat bran).

Inhibition of Fatty Acid Synthesis in Rat Mammary Gland Slices by Cortisone in Vitro and its Antagonism by Insulin

Nature ◽  
1952 ◽  
Vol 169 (4298) ◽  
pp. 447-449 ◽  
Author(s):  
JUDITH H. BALMAIN ◽  
S. J. FOLLEY ◽  
R. F. GLASCOCK
Keyword(s):  
Mammary Gland ◽  
Fatty Acid ◽  
Fatty Acid Synthesis ◽  
Acid Synthesis ◽  
Rat Mammary Gland

Prolactin-stimulated polymerization of acetyl-CoA carboxylase in explants of mid-pregnant rat mammary gland

2001 ◽  
Vol 68 (3) ◽  
pp. 351-355 ◽  
Author(s):  
JULIUS E. OBEN ◽  
RAYMOND R. DILS
Keyword(s):  
Mammary Gland ◽  
Fatty Acid ◽  
Fatty Acid Synthesis ◽  
Specific Activity ◽  
Acid Synthesis ◽  
Acetyl Coa Carboxylase ◽  
Acetyl Coa ◽  
Pregnant Rat ◽  
Rat Mammary Gland ◽  
Total Enzyme

Prolactin significantly increased the rate of fatty acid synthesis in explants of mid-pregnant rat mammary gland cultured for 96 h with insulin plus corticosterone. Under these conditions, prolactin increased the specific activity of total acetyl-CoA carboxylase in nuclear-free homogenates of explants by 2·6, and increased the proportion of the enzyme in the active polymeric form from 0·44 to 0·89. Removal of prolactin after 48 h in culture decreased the specific activity of the total enzyme by about half, and decreased the proportion as polymer to 0·52. The results show that prolactin plays a major role in mid-pregnant rat mammary gland in the polymerization which accompanies increased activity of the total enzyme and increased rate of fatty acid synthesis.

Increased rates of hepatic cholesterogenesis and fatty acid synthesis in septic rats in vivo: evidence for the possible involvement of insulin

1989 ◽  
Vol 76 (2) ◽  
pp. 205-211 ◽  
Author(s):  
Paulo R. L. de Vasconcelos ◽  
Michael G. W. Kettlewell ◽  
Geoffrey F. Gibbons ◽  
Dermot H. Williamson
Keyword(s):  
Fatty Acid ◽  
Fatty Acid Synthesis ◽  
Plasma Insulin ◽  
Total Activity ◽  
Acid Synthesis ◽  
Hmg Coa Reductase ◽  
Coa Reductase ◽  
Caecal Ligation And Puncture ◽  
Hepatic Cholesterogenesis

1. Sepsis induced by caecal ligation and puncture increased the rates of hepatic cholesterogenesis and fatty acid synthesis in vivo compared with sham-operated rats. These changes were accompanied by higher concentrations of lactate and pyruvate in blood and liver and an increase in plasma insulin. 2. The total activity of hydroxymethylglutarylcoenzyme A (HMG-CoA) reductase (EC 1.1.1.88) in liver was increased by sepsis, but there was no significant change in the expressed activity. Short-term insulin deficiency (induced by mannoheptulose or streptozotocin) decreased the rates of cholesterogenesis and fatty acid synthesis in livers of septic rats but did not alter the expressed/total activity of HMG-CoA reductase. 3. It is concluded that the increased rate of hepatic cholesterogenesis in septic rats is in part a result of the higher plasma insulin, the hormone acting to maintain the total activity of HMG-CoA reductase and to stimulate a step before the formation of HMG-CoA. 4. These changes may contribute to the hypertriacyl-glycerolaemia associated with sepsis.

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