Abstract
The effect of hyperthermia (1 hr, 41°C) on the functional properties of Ehrlich ascites tumor mitochondria was investigated. Mitochondria isolated from Ehrlich ascites tumor after exposure of whole cells to 41°C for 1 hr still phosphorylate and maintain a normal acceptor control ratio (ACR). The temperature decreases state 4 and ADP- and FCCP-stimulated respiration on various substrates entering at three energy-conserving sites of the respiratory chain. The inhibition of oxygen consumption by NAD- and FAD-linked substrates was 40% for state 4 and 70% for ADP- or FCCP-stimulated respiration. State 4 and FCCP-stimulated respiration of mitochondria on TMPD + ascorbate was affected 38% and 45%, respectively. ATPase activity was unaffected by hyperthermia, indicating that under these experimental conditions, the inhibition of ADP-stimulated respiration does not depend on an effect on either Fo F4-ATPase or adenine translocase, the activity of which is required for ATP entry prior to ATPase activity. Because of the inability to detect a specific site of action of temperature, it is conceivable that hyperthermia might inhibit substrate oxidation by altering some components of the inner mitochondrial membrane, which regulates the kinetic properties of the membrane-associated enzymes.
| Original language | English |
|---|---|
| Pages (from-to) | 279-293 |
| Number of pages | 15 |
| Journal | Experimental and Molecular Pathology |
| Volume | 46 |
| Issue number | 3 |
| DOIs | |
| Publication status | Published - 1987 |
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ASJC Scopus subject areas
- Clinical Biochemistry
- Molecular Biology
- Pathology and Forensic Medicine
Cite this
Effect of hyperthermia on electron transport in ehrlich ascites tumor mitochondria. / Floridi, A.; Nista, A.; Paggi, M. G.; Pellegrini, L.; Bagnato, A.; Fanciulli, M.; Caputo, A.
In: Experimental and Molecular Pathology, Vol. 46, No. 3, 1987, p. 279-293.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Effect of hyperthermia on electron transport in ehrlich ascites tumor mitochondria
AU - Floridi, A.
AU - Nista, A.
AU - Paggi, M. G.
AU - Pellegrini, L.
AU - Bagnato, A.
AU - Fanciulli, M.
AU - Caputo, A.
PY - 1987
Y1 - 1987
N2 - The effect of hyperthermia (1 hr, 41°C) on the functional properties of Ehrlich ascites tumor mitochondria was investigated. Mitochondria isolated from Ehrlich ascites tumor after exposure of whole cells to 41°C for 1 hr still phosphorylate and maintain a normal acceptor control ratio (ACR). The temperature decreases state 4 and ADP- and FCCP-stimulated respiration on various substrates entering at three energy-conserving sites of the respiratory chain. The inhibition of oxygen consumption by NAD- and FAD-linked substrates was 40% for state 4 and 70% for ADP- or FCCP-stimulated respiration. State 4 and FCCP-stimulated respiration of mitochondria on TMPD + ascorbate was affected 38% and 45%, respectively. ATPase activity was unaffected by hyperthermia, indicating that under these experimental conditions, the inhibition of ADP-stimulated respiration does not depend on an effect on either Fo F4-ATPase or adenine translocase, the activity of which is required for ATP entry prior to ATPase activity. Because of the inability to detect a specific site of action of temperature, it is conceivable that hyperthermia might inhibit substrate oxidation by altering some components of the inner mitochondrial membrane, which regulates the kinetic properties of the membrane-associated enzymes.
AB - The effect of hyperthermia (1 hr, 41°C) on the functional properties of Ehrlich ascites tumor mitochondria was investigated. Mitochondria isolated from Ehrlich ascites tumor after exposure of whole cells to 41°C for 1 hr still phosphorylate and maintain a normal acceptor control ratio (ACR). The temperature decreases state 4 and ADP- and FCCP-stimulated respiration on various substrates entering at three energy-conserving sites of the respiratory chain. The inhibition of oxygen consumption by NAD- and FAD-linked substrates was 40% for state 4 and 70% for ADP- or FCCP-stimulated respiration. State 4 and FCCP-stimulated respiration of mitochondria on TMPD + ascorbate was affected 38% and 45%, respectively. ATPase activity was unaffected by hyperthermia, indicating that under these experimental conditions, the inhibition of ADP-stimulated respiration does not depend on an effect on either Fo F4-ATPase or adenine translocase, the activity of which is required for ATP entry prior to ATPase activity. Because of the inability to detect a specific site of action of temperature, it is conceivable that hyperthermia might inhibit substrate oxidation by altering some components of the inner mitochondrial membrane, which regulates the kinetic properties of the membrane-associated enzymes.
UR - http://www.scopus.com/inward/record.url?scp=0023256281&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=0023256281&partnerID=8YFLogxK
U2 - 10.1016/0014-4800(87)90050-5
DO - 10.1016/0014-4800(87)90050-5
M3 - Article
C2 - 2954847
AN - SCOPUS:0023256281
VL - 46
SP - 279
EP - 293
JO - Experimental and Molecular Pathology
JF - Experimental and Molecular Pathology
SN - 0014-4800
IS - 3
ER -