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

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.

1988 ◽  
Vol 255 (1) ◽  
pp. R141-R148 ◽  
Author(s):  
B. P. Warwick ◽  
D. R. Romsos

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).


1978 ◽  
Vol 176 (1) ◽  
pp. 343-346 ◽  
Author(s):  
A M Robinson ◽  
J R Girard ◽  
D H Williamson

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.


1972 ◽  
Vol 102 (5) ◽  
pp. 617-623 ◽  
Author(s):  
D. L. Ingle ◽  
D. E. Bauman ◽  
U. S. Garrigus

2000 ◽  
Vol 22 (1) ◽  
pp. 39-50 ◽  
Author(s):  
Xiaoming Bao ◽  
Manfred Focke ◽  
Mike Pollard ◽  
John Ohlrogge

2000 ◽  
Vol 80 (1) ◽  
pp. 59-67 ◽  
Author(s):  
J. A. Moibi ◽  
R. J. Christopherson ◽  
E. K. Okine

Twenty-four wether lambs were randomly allocated to six treatments to investigate the effect of temperature and dietary lipid supplements on fatty acid synthesis and metabolic activity in sheep. The treatments consisted of four groups exposed to either cold (0 °C) or warm temperature (+23 °C) and given ad libitum access to either a control barley-based diet or with lipid supplementation. Two other groups were placed on the dietary regimen at 0 °C, but pair-fed to intake of animals in the +23 °C environment. At 5 wk, fatty acid synthesis was measured by [1-14C]acetate incorporation into tissue lipids. Cold exposure and dietary lipid supplementation had no effect (P > 0.05) on in vivo fatty acid synthesis rates in either longissimus dorsi or the liver. In both subcutaneous and mesenteric adipose tissue depots, the rate of acetate incorporation into tissue lipid was not significantly affected by cold exposure. In the perirenal fat depot, cold exposure increased (P < 0.05) the rate of fatty acid synthesis, while lipid supplementation decreased (P < 0.05) the rate in all tissue adipose depots. In vitro, mesenteric and perirenal adipose tissues from cold pair-fed animals had higher (P < 0.05) rates of fatty acid synthesis compared to tissues from animals in the warm environment. However, there was no effect of dietary lipid supplementation in these two fat depots. Metabolic heat production, and energy and nitrogen excretion by animals were increased (P < 0.05) by cold exposure while lipid supplementation had the opposite effect (P < 0.05). The relationship between average daily gain and feed intake was linear at both warm and cold environments, but with higher (P < 0.05) average daily gain at all levels of intake in the cold compared to the warm environment. Results indicate that both environment and diet regulate metabolic activity in sheep. However, there were differences in lipogenic response by tissues to the treatments. Key words: Environmental temperature, dietary lipid, fatty acid synthesis, metabolic rate, sheep


1984 ◽  
Vol 52 (1) ◽  
pp. 131-137 ◽  
Author(s):  
G. R. Herzberg ◽  
Minda Rogerson

1. The effect of feeding casein, lactalbumin, soya-bean protein, gluten or gelatin on hepatic lipogenesis and the levels of hepatic fatty acid synthetase (FAS), glucose-6-phosphate dehydrogenase (EC 1. 1. 1.49; G6PD), malic enzyme (EC 1. 1. 1.40; ME) ATP-citrate lyase (EC 4. 1. 3. 8; CL), acetyl CoA carboxylase (EC 6.4.1.2; ACCx) and glucokinase (EC 2. 7. 1. 2; GK) was examined in young growing rats.2. The total activities of ACCx, FAS, CL, GK, G6PD, GK, ME and fatty acid synthesis in vivo were positively correlated with protein quality.3. The specific activities of ACCx, FAS, CL, G6PD and fatty acid synthesis in vivo were positively correlated with protein quality.4. The specific activities of GK and ME were unrelated to protein quality.5. The results demonstrate a dissociation between ME and hepatic lipogenesis and suggest a role for the NADPH generated by ME which is not related to the needs of fatty acid synthesis.


1983 ◽  
Vol 245 (1) ◽  
pp. E8-E13
Author(s):  
K. Tokuyama ◽  
H. Okuda

The effect of physical training on fatty acid synthesis in vivo was studied. After the rats had free access to a running wheel for 50 days, the rate of fatty acid synthesis estimated using 3H2O in adipose tissues of trained rats was about three times higher than that of sedentary rats in both the light and dark period. The rate of fatty acid synthesis in the liver but not in the brown adipose tissue was also slightly enhanced by physical training. The number of adipocytes was not affected, but the size of adipocytes was reduced by physical training. In trained rats, the rate of fatty acid synthesis in adipocytes whose diameter was similar to that of sedentary rats was about 10 times higher than that of sedentary rats. Within adipose tissue, the rate of fatty acid synthesis correlated positively to the diameter of adipocytes both in the sedentary and trained rats. These findings mean that the adaptive increase in fatty acid synthesis seen in adipocytes of trained rats is not secondary to the reduction in size of adipocytes.


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