The effects of octopamine on contraction kinetics and power output of a locust flight muscle

1988 ◽  
Vol 162 (6) ◽  
pp. 827-835 ◽  
Author(s):  
Jean G. Malamud ◽  
Andrew P. Mizisin ◽  
Robert K. Josephson
Keyword(s):  
Power Output ◽  
Flight Muscle ◽  
Locust Flight ◽  
Contraction Kinetics

Mechanical power output of locust flight muscle

1987 ◽  
Vol 160 (3) ◽  
pp. 413-419 ◽  
Author(s):  
Andrew P. Mizisin ◽  
Robert K. Josephson
Keyword(s):  
Power Output ◽  
Flight Muscle ◽  
Mechanical Power ◽  
Locust Flight ◽  
Mechanical Power Output

scholarly journals Alterations in flight muscle ultrastructure and function in Drosophila tropomyosin mutants.

1996 ◽  
Vol 135 (3) ◽  
pp. 673-687 ◽  
Author(s):  
A J Kreuz ◽  
A Simcox ◽  
D Maughan
Keyword(s):  
Amino Acid ◽  
Power Output ◽  
Flight Muscle ◽  
Structure And Function ◽  
Wild Type ◽  
Muscle Tropomyosin ◽  
Ultrastructure And Function ◽  
And Function ◽  
Net Power Output ◽  
Current Report

Drosophila indirect flight muscle (IFM) contains two different types of tropomyosin: a standard 284-amino acid muscle tropomyosin, Ifm-TmI, encoded by the TmI gene, and two > 400 amino acid tropomyosins, TnH-33 and TnH-34, encoded by TmII. The two IFM-specific TnH isoforms are unique tropomyosins with a COOH-terminal extension of approximately 200 residues which is hydrophobic and rich in prolines. Previous analysis of a hypomorphic TmI mutant, Ifm(3)3, demonstrated that Ifm-TmI is necessary for proper myofibrillar assembly, but no null TmI mutant or TmII mutant which affects the TnH isoforms have been reported. In the current report, we show that four flightless mutants (Warmke et al., 1989) are alleles of TmI, and characterize a deficiency which deletes both TmI and TmII. We find that haploidy of TmI causes myofibrillar disruptions and flightless behavior, but that haploidy of TmII causes neither. Single fiber mechanics demonstrates that power output is much lower in the TmI haploid line (32% of wild-type) than in the TmII haploid line (73% of wild-type). In myofibers nearly depleted of Ifm-TmI, net power output is virtually abolished (< 1% of wild-type) despite the presence of an organized fibrillar core (approximately 20% of wild-type). The results suggest Ifm-TmI (the standard tropomyosin) plays a key role in fiber structure, power production, and flight, with reduced Ifm-TmI expression producing corresponding changes of IFM structure and function. In contrast, reduced expression of the TnH isoforms has an unexpectedly mild effect on IFM structure and function.

Dynamics of in vivo power output and efficiency of Nasonia asynchronous flight muscle

2006 ◽  
Vol 124 (1) ◽  
pp. 93-107 ◽  
Author(s):  
Fritz-Olaf Lehmann ◽  
Nicole Heymann
Keyword(s):  
Power Output ◽  
Flight Muscle

Power output by an asynchronous flight muscle from a beetle

2000 ◽  
Vol 203 (17) ◽  
pp. 2667-2689 ◽  
Author(s):  
R.K. Josephson ◽  
J.G. Malamud ◽  
D.R. Stokes
Keyword(s):  
Power Output ◽  
Flight Muscle ◽  
Muscle Length ◽  
Mechanical Power ◽  
Effect Of Temperature ◽  
Muscle Temperature ◽  
Work Output ◽  
Stroke Frequency ◽  
Mechanical Power Output ◽  
Wing Stroke

The basalar muscle of the beetle Cotinus mutabilis is a large, fibrillar flight muscle composed of approximately 90 fibers. The paired basalars together make up approximately one-third of the mass of the power muscles of flight. Changes in twitch force with changing stimulus intensity indicated that a basalar muscle is innervated by at least five excitatory axons and at least one inhibitory axon. The muscle is an asynchronous muscle; during normal oscillatory operation there is not a 1:1 relationship between muscle action potentials and contractions. During tethered flight, the wing-stroke frequency was approximately 80 Hz, and the action potential frequency in individual motor units was approximately 20 Hz. As in other asynchronous muscles that have been examined, the basalar is characterized by high passive tension, low tetanic force and long twitch duration. Mechanical power output from the basalar muscle during imposed, sinusoidal strain was measured by the work-loop technique. Work output varied with strain amplitude, strain frequency, the muscle length upon which the strain was superimposed, muscle temperature and stimulation frequency. When other variables were at optimal values, the optimal strain for work per cycle was approximately 5%, the optimal frequency for work per cycle approximately 50 Hz and the optimal frequency for mechanical power output 60–80 Hz. Optimal strain decreased with increasing cycle frequency and increased with muscle temperature. The curve relating work output and strain was narrow. At frequencies approximating those of flight, the width of the work versus strain curve, measured at half-maximal work, was 5% of the resting muscle length. The optimal muscle length for work output was shorter than that at which twitch and tetanic tension were maximal. Optimal muscle length decreased with increasing strain. The curve relating work output and muscle length, like that for work versus strain, was narrow, with a half-width of approximately 3 % at the normal flight frequency. Increasing the frequency with which the muscle was stimulated increased power output up to a plateau, reached at approximately 100 Hz stimulation frequency (at 35 degrees C). The low lift generated by animals during tethered flight is consistent with the low frequency of muscle action potentials in motor units of the wing muscles. The optimal oscillatory frequency for work per cycle increased with muscle temperature over the temperature range tested (25–40 degrees C). When cycle frequency was held constant, the work per cycle rose to an optimum with increasing temperature and then declined. We propose that there is a temperature optimum for work output because increasing temperature increases the shortening velocity of the muscle, which increases the rate of positive work output during shortening, but also decreases the durations of the stretch activation and shortening deactivation that underlie positive work output, the effect of temperature on shortening velocity being dominant at lower temperatures and the effect of temperature on the time course of activation and deactivation being dominant at higher temperatures. The average wing-stroke frequency during free flight was 94 Hz, and the thoracic temperature was 35 degrees C. The mechanical power output at the measured values of wing-stroke frequency and thoracic temperature during flight, and at optimal muscle length and strain, averaged 127 W kg(−1)muscle, with a maximum value of 200 W kg(−1). The power output from this asynchronous flight muscle was approximately twice that measured with similar techniques from synchronous flight muscle of insects, supporting the hypothesis that asynchronous operation has been favored by evolution in flight systems of different insect groups because it allows greater power output at the high contraction frequencies of flight.

Partial purification of locust flight muscle lipoprotein lipase (LpL): apparent differences from mammalian LpL

1987 ◽  
Vol 88 (2) ◽  
pp. 523-527 ◽  
Author(s):  
M.C. van Heusden ◽  
D.J. van der Horst ◽  
J.M. van Doorn ◽  
A.M.Th. Beenakkers
Keyword(s):  
Lipoprotein Lipase ◽  
Flight Muscle ◽  
Partial Purification ◽  
Locust Flight

Developmental changes of FABP concentration, expression, and intracellular distribution in locust flight muscle

1993 ◽  
Vol 123 (1-2) ◽  
pp. 153-158 ◽  
Author(s):  
Norbert H. Haunerland ◽  
Xinmei Chen ◽  
Peter Andolfatto ◽  
Joan M. Chisholm ◽  
Zhixiang Wang
Keyword(s):  
Flight Muscle ◽  
Intracellular Distribution ◽  
Developmental Changes ◽  
Locust Flight

scholarly journals Long-term effects of the trehalase inhibitor trehazolin on trehalase activity in locust flight muscle

2010 ◽  
Vol 213 (22) ◽  
pp. 3852-3857 ◽  
Author(s):  
G. Wegener ◽  
C. Macho ◽  
P. Schloder ◽  
G. Kamp ◽  
O. Ando
Keyword(s):  
Flight Muscle ◽  
Long Term Effects ◽  
Trehalase Activity ◽  
Locust Flight
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