Chloramphenicol and Ethidium Bromide Effects on Flight-Muscle Mitochondria of the Blowfly Calliphora erythrocephala

1978 ◽  
Vol 6 (5) ◽  
pp. 978-980 ◽  
Author(s):  
B. M. ASHOUR ◽  
S. M. DANKS ◽  
P. A. WHITTAKER
Keyword(s):  
Ethidium Bromide ◽  
Flight Muscle ◽  
Calliphora Erythrocephala ◽  
Muscle Mitochondria

Biochemical and Structural Variations in the Flight Muscle Mitochondria of Ageing Blowflies, Calliphora Erythrocephala

1972 ◽  
Vol 10 (2) ◽  
pp. 443-469 ◽  
Author(s):  
M. A. TRIBE ◽  
DOREEN E. ASHHURST
Keyword(s):  
Flight Muscle ◽  
Mitochondrial Protein ◽  
Mitochondrial Proteins ◽  
Mitochondrial Protein Synthesis ◽  
Structural Variations ◽  
Calliphora Erythrocephala ◽  
Muscle Mitochondria ◽  
Mitochondrial Structure ◽  
Age Related ◽  
Age Related Changes

Biochemical investigations with isolated blowfly flight muscle mitochondria show that uncoupling of oxidation and phosphorylation increases with increasing age of the adult fly. Of the two principal substrates used (i.e. α-glycerophosphate and pyruvate), uncoupling is most marked when α-glycerophosphate is used as substrate. Although age-related changes in the structure of the thoracic flight muscle are observed by electron-microscope studies, no obvious degenerative changes take place in either the mitochondrial structure or the myofibrils of old flies. Labelling experiments with [3H] leucine indicate that uncoupling is mainly due to the lack of repair and replacement of mitochondrial proteins. These experiments also show that mitochondrial protein synthesis is important in the maturation of young flies, that is, those between 0 and 4 days old, but is insignificant in the further increase in mitochondrial size observed in older flies, where mitochondrial fusion appears to be more important.

scholarly journals The effect of the coupled oxidation of substrate on the permeability of blowfly flight-muscle mitochondria to potassium and other cations

1972 ◽  
Vol 126 (3) ◽  
pp. 689-700 ◽  
Author(s):  
R. G. Hansford ◽  
A. L. Lehninger
Keyword(s):  
Light Scattering ◽  
Flight Muscle ◽  
Unit Area ◽  
Membrane Surface ◽  
Mitochondrial Matrix ◽  
Exposed Area ◽  
Muscle Mitochondria ◽  
Area 5 ◽  
Choline Phosphate ◽  
Permeant Anion

1. Blowfly flight-muscle mitochondria respiring in the absence of phosphate acceptor (i.e. in state 4) take up greater amounts of K+, Na+, choline, phosphate and Cl-(but less NH4+) than non-respiring control mitochondria. 2. Uptake of cations is accompanied by an increase in the volume of the mitochondrial matrix, determined with the use of [14C]-sucrose and3H2O. The osmolarity of the salt solution taken up was approximately that of the suspending medium. 3. The [14C]sucrose-inaccessible space decreased with increasing osmolarity of potassium chloride in the suspending medium, confirming that the blowfly mitochondrion behaves as an osmometer. 4. Light-scattering studies showed that both respiratory substrate and a permeant anion such as phosphate or acetate are required for rapid and massive entry of K+, which occurs in an electrophoretic process rather than in exchange for H+. The increase in permeability to K+and other cations is probably the result of a large increase in the exposed area of inner membrane surface in these mitochondria, with no intrinsic increase in the permeability per unit area. 5. No increase in permeability to K+and other cations occurs during phosphorylation of ADP in state 3 respiration.

The effect of chloramphenicol, ethidium bromide and cycloheximide on mortality and mitochondrial protein synthesis of adult blowflies

1980 ◽  
Vol 41 (1) ◽  
pp. 273-289
Author(s):  
B. Ashour ◽  
M. Tribe ◽  
P. Whittaker
Keyword(s):  
Protein Synthesis ◽  
Amino Acid ◽  
Drug Treatment ◽  
Ethidium Bromide ◽  
Flight Muscle ◽  
Mitochondrial Protein ◽  
Age Groups ◽  
Age Group ◽  
Mitochondrial Protein Synthesis ◽  
Inhibition Of Protein Synthesis

The effects of cycloheximide, chloramphenicol and ethidium bromide on the blowfly Calliphora erythrocephala were studied. In the first set of experiments, toxic levels were determined by examining activity and mortality of flies after injection of various doses of each drug. In the second set of experiments, the effect of drug treatment on flight muscle mitochondrial protein synthesis was determined in relation to age by following the incorporation of radioactively labelled amino acid, [3H]leucine, into mitochondrial protein in vivo. To confirm the developmental changes in flight muscle mitochondria, mitochondrial protein content per fly was estimated from emergence to 30 days of age; the highest protein level was recorded between 6 and 10 days of age. Maximum incorporation of labelled amino acid was found in newly emerged flies, and this age group was also the most sensitive to drug treatment. By the time flies had reached 6–10 days of age, amino acid incorporation had declined to about two-thirds of the rate obtained with newly emerged flies. With 6–10-day old flies, however, the highest value for flight muscle mitochondrial protein per fly was recorded, and these flies also displayed the greatest resistance to drug treatment of any age group investigated. For example, inhibition of protein synthesis following injection of 300 micrograms/fly of chloramphenicol was only about 15% below the untreated control in 6–10-day-old flies, whereas in all other age groups investigated, inhibition ranged between 30 and 50% of the controls. At 15–20 days of age, protein synthesis decreased to a third of the newly emerged flies' rate and continued to decrease further in the 30–35-day-old group, where it was less than one sixth of the youngest age group. The effect of drug treatment on these older flies was also less than that observed with newly emerged flies, especially after chloramphenicol and ethidium bromide injections. The effect of cycloheximide however, was much the same in all age groups, with inhibition of protein synthesis being 80–90% of controls. Surprisingly, cycloheximide (1–10 micrograms/fly) had little initial effect on mortality of young flies, despite almost complete blockage in the synthesis of mitochondrial proteins at these concentrations. 95% mortality occurred only when doses of 20 micrograms/fly were given. In contrast, high doses of chloramphenicol (400 micrograms/fly) and ethidium bromide (15 micrograms/fly) caused almost total mortality a few hours after injection, although such doses never induced more than about 50% inhibition of mitochondrial protein synthesis. Each drug therefore has a different site of inhibition and induces different mortality effects. Possible explanations for these differences in mortality are discussed.

scholarly journals The control of tricarboxylate-cycle oxidations in blowfly flight muscle. The steady-state concentrations of citrate, isocitrate 2-oxoglutarate and malate in flight muscle and isolated mitochondria

1975 ◽  
Vol 146 (3) ◽  
pp. 527-535 ◽  
Author(s):  
R N Johnson ◽  
R G Hansford
Keyword(s):  
Redox State ◽  
Flight Muscle ◽  
Total Content ◽  
Phormia Regina ◽  
Experimental Conditions ◽  
Main Determinant ◽  
Muscle Mitochondria ◽  
Isolated Mitochondria ◽  
Tricarboxylate Cycle

1. Blowfly (Phormia regina) flight-muscle mitochondria were allowed to oxidize pyruvate under a variety of experimental conditions, and determinations of the citrate, isocitrate, 2-oxoglutarate and malate contents of both the mitochondria and the incubation medium were made. For each intermediate a substantial portion of the total was present within the mitochondria. 2. Activation of respiration by either ADP or uncoupling agent resulted in a decreased content of citrate and isocitrate and an increased content of 2-oxoglutarate and malate when the substrate was pyruvate, APT and HCO3 minus. Such a decrease in citrate content was obscured when the substrate was pyruvate and proline owing to a large rise in the total content of tricarboxylate-cycle intermediates in the presence of proline and ADP. 3. An experiment involving oligomycin and uncoupling agent demonstrated that the ATP/ADP ratio is the main determinant of flux through the tricarboxylate cycle, with the redox state of nicotinamide nucleotide being of lesser importance. 4. Addition of ADP and Ca-2+ to activate the oxidation of both glycerol 3-phosphate and pyruvate, simulating conditions on initiation of flight, gave a decrease in citrate and isocitrate and an increase in 2-oxoglutarate and malate content. 5. There was a good correlation between these results with isolated flight-muscle mitochondria and the changes found in fly thoraces after 30s and 2 mihorax. 6. It is concluded that NAD-isocitrate dehydrogenase (EC 1.1.1.41) controls the rate of pyruvate oxidation in both resting fly flight muscle in vivo and isolated mitochondria in state 4 (nomenclature of Change & Williams, 1955).

scholarly journals Blood-Feeding Induces Reversible Functional Changes in Flight Muscle Mitochondria of Aedes aegypti Mosquito

PLoS ONE ◽  
2009 ◽  
Vol 4 (11) ◽  
pp. e7854 ◽  
Author(s):  
Renata L. S. Gonçalves ◽  
Ana Carolina L. Machado ◽  
Gabriela O. Paiva-Silva ◽  
Marcos H. F. Sorgine ◽  
Marisa M. Momoli ◽  
...  
Keyword(s):  
Aedes Aegypti ◽  
Flight Muscle ◽  
Blood Feeding ◽  
Muscle Mitochondria ◽  
Functional Changes
Sign in / Sign up

Export Citation Format

Share Document