Cold temperature blocks thyroid hormone-induced changes in lipid and energy metabolism in the liver of Lithobates catesbeianus tadpoles

The influence of ConA on the energy metabolism of quiescent rat thymocytes was investigated by measuring the effects of inhibitors of protein synthesis, proteolysis, RNA/DNA synthesis, Na+K+-ATPase, Ca2+-ATPase and mitochondrial ATP synthesis on respiration. Only about 50% of the coupled oxygen consumption of quiescent thymocytes could be assigned to specific processes using two different media. Under these conditions the oxygen is mainly used to drive mitochondrial proton leak and to provide ATP for protein synthesis and cation transport, whereas oxygen consumption to provide ATP for RNA/DNA synthesis and ATP-dependent proteolysis was not measurable. The mitogen ConA produced a persistent increase in oxygen consumption by about 30% within seconds. After stimulation more than 80% of respiration could be assigned to specific processes. The major oxygen consuming processes of ConA-stimulated thymocytes are mitochondrial proton leak, protein synthesis and Na+K+-ATPase with about 20% each of total oxygen consumption, while Ca2+-ATPase and RNA/DNA synthesis contribute about 10% each. Quiescent thymocytes resemble resting hepatocytes in that most of the oxygen consumption remains unexplained. In constrast, the pattern of energy metabolism in stimulated thymocytes is similar to that described for Ehrlich Ascites tumour cells and splenocytes, which may also be in an activated state. Most of the oxygen consumption is accounted for, so the unexplained process(es) in unstimulated cells shut(s) off on stimulation.

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ConA induced changes in energy metabolism of rat thymocytes

Bioscience Reports ◽

10.1007/bf02351215 ◽

1992 ◽

Vol 12 (2) ◽

pp. 109-114 ◽

Cited By ~ 10

Author(s):

F. Buttgereit ◽

M. D. Brand ◽

M. Müller

Keyword(s):

Protein Synthesis ◽

Oxygen Consumption ◽

Energy Metabolism ◽

Dna Synthesis ◽

Atp Synthesis ◽

Proton Leak ◽

Ehrlich Ascites ◽

Activated State ◽

Ehrlich Ascites Tumour ◽

Induced Changes

The influence of ConA on the energy metabolism of quiescent rat thymocytes was investigated by measuring the effects of inhibitors of protein synthesis, proteolysis, RNA/DNA synthesis, Na+K+-ATPase, Ca2+-ATPase and mitochondrial ATP synthesis on respiration. Only about 50% of the coupled oxygen consumption of quiescent thymocytes could be assigned to specific processes using two different media. Under these conditions the oxygen is mainly used to drive mitochondrial proton leak and to provide ATP for protein synthesis and cation transport, whereas oxygen consumption to provide ATP for RNA/DNA synthesis and ATP-dependent proteolysis was not measurable. The mitogen ConA produced a persistent increase in oxygen consumption by about 30% within seconds. After stimulation more than 80% of respiration could be assigned to specific processes. The major oxygen consuming processes of ConA-stimulated thymocytes are mitochondrial proton leak, protein synthesis and Na+K+-ATPase with about 20% each of total oxygen consumption, while Ca2+-ATPase and RNA/DNA synthesis contribute about 10% each. Quiescent thymocytes resemble resting hepatocytes in that most of the oxygen consumption remains unexplained. In contrast, the pattern of energy metabolism in stimulated thymocytes is similar to that described for Ehrlich Ascites tumour cells and splenocytes, which may also be in an activated state. Most of the oxygen consumption is accounted for, so the unexplained process(es) in unstimulated cells shut(s) off on stimulation.

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INDUCED CHANGES IN ENERGY METABOLISM

Mechanisms in Bioenergetics ◽

10.1016/b978-0-12-574662-5.50023-7 ◽

1965 ◽

pp. 241-253 ◽

Cited By ~ 1

Author(s):

EFRAIM RACKER

Keyword(s):

Energy Metabolism ◽

Induced Changes

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Aspirin Induced Changes in Enzymes of Colonic Energy Metabolism and ATPases of Rats Exposed to Cycas and Fed a Nigerian-Like Diet

Journal of Medical Sciences(Faisalabad) ◽

10.3923/jms.2007.1250.1258 ◽

2007 ◽

Vol 7 (8) ◽

pp. 1250-1258

Author(s):

G.E. Eriyamremu ◽

E.C. Onyeneke . ◽

N.J. Orhue . ◽

S.I. Ojeaburu . ◽

S.O. Uanseoje . ◽

...

Keyword(s):

Energy Metabolism ◽

Induced Changes

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Neutralization of TNF does not influence endotoxininduced changes in thyroid hormone metabolism in humans

AJP Regulatory Integrative and Comparative Physiology ◽

10.1152/ajpregu.1999.276.2.r357 ◽

1999 ◽

Vol 276 (2) ◽

pp. R357-R362 ◽

Cited By ~ 3

Author(s):

Tom van der Poll ◽

Erik Endert ◽

Susette M. Coyle ◽

Jan M. Agosti ◽

Stephen F. Lowry

Keyword(s):

Thyroid Hormone ◽

Thyroid Stimulating Hormone ◽

Hormone Metabolism ◽

Thyroid Hormone Metabolism ◽

Healthy Humans ◽

Transient Rise ◽

Induced Changes ◽

Necrosis Factor ◽

Control Study

To determine the role of tumor necrosis factor (TNF) in endotoxin-induced changes in plasma thyroid hormone and thyroid-stimulating hormone (TSH) concentrations, 24 healthy postabsorptive humans were studied on a control study day ( n= 6), after infusion of a recombinant TNF receptor IgG fusion protein (TNFR:Fc; 6 mg/m2; n = 6) after intravenous injection of endotoxin (2 ng/kg; n = 6), or after administration of endotoxin with TNFR:Fc ( n = 6). Administration of TNFR:Fc alone did not affect thyroid hormone or TSH levels when compared with the control day. Endotoxin induced a transient rise in plasma TNF activity (1.5 h: 219 ± 42 pg/ml), which was completely prevented by TNFR:Fc ( P < 0.05). After endotoxin administration, plasmal-thyroxine (T4), free T4, 3,5,3′-triiodothyronine (T3), and TSH were lower and 3,3′,5′-triiodothyronine was higher than on the control day (all P < 0.05). Coinfusion of TNFR:Fc with endotoxin did not influence these endotoxin-induced changes. Our results suggest that endogenous TNF does not play an important role in the alterations in plasma thyroid hormone and TSH concentrations induced by mild endotoxemia in healthy humans.

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