The Function and Metabolism of Certain Insect Muscles in Relation to their Structure

1955 ◽  
Vol s3-96 (34) ◽  
pp. 151-159
Author(s):  
GEORGE A. EDWARDS ◽  
HELMUT RUSKA

Electron microscopic observations on ultrathin sections of the red thoracic flightmuscles and white leg muscles of Hydrophilus and Dytiscus are reported. In red muscle-fibres with high values in frequency of contraction, oxygen consumption, and dehydrogenase activity, the single fibrils are completely surrounded by huge mitochondria. Tracheoles penetrate the sarcolemma and supply the mitochondria with oxygen by intracellular branches. In the less active white muscle fibres, mitochondria are found irregularly scattered between the fibrils or along the I band. The intracellular tracheolization is sparse but an endoplasmic reticulum is widely spread between the synfibrillar contractile material. The same muscles of the two insects differ considerably in detail.

Author(s):  
J. P. Petrali ◽  
E. J. Donati ◽  
L. A. Sternberger

Specific contrast is conferred to subcellular antigen by applying purified antibodies, exhaustively labeled with uranium under immunospecific protection, to ultrathin sections. Use of Seligman’s principle of bridging osmium to metal via thiocarbohydrazide (TCH) intensifies specific contrast. Ultrathin sections of osmium-fixed materials were stained on the grid by application of 1) thiosemicarbazide (TSC), 2) unlabeled specific antiserum, 3) uranium-labeled anti-antibody and 4) TCH followed by reosmication. Antigens to be localized consisted of vaccinia antigen in infected HeLa cells, lysozyme in monocytes of patients with monocytic or monomyelocytic leukemia, and fibrinogen in the platelets of these leukemic patients. Control sections were stained with non-specific antiserum (E. coli).In the vaccinia-HeLa system, antigen was localized from 1 to 3 hours following infection, and was confined to degrading virus, the inner walls of numerous organelles, and other structures in cytoplasmic foci. Surrounding architecture and cellular mitochondria were unstained. 8 to 14 hours after infection, antigen was localized on the outer walls of the viral progeny, on cytoplasmic membranes, and free in the cytoplasm. Staining of endoplasmic reticulum was intense and focal early, and weak and diffuse late in infection.


1984 ◽  
Vol 110 (1) ◽  
pp. 217-229 ◽  
Author(s):  
R. S. Batty

A kinematic analysis was made of swimming of larval herring Clupea harengus L. Swimming style was found to change with growth and development; the amplitude of swimming movements of early post-yolk-sac larvae increases linearly towards the tail, a style of swimming which relies mainly on resistive forces for propulsion. Later, after the caudal and dorsal fins have developed, the swimming style changes, in response to an increase in Reynold's Number, such that inertial forces are more important. In this type of swimming the amplitude increases more rapidly than linearly towards the tail. The distribution of red and white muscle fibre types was studied in relation to development. On hatching, red muscle fibres were found to be arranged as a single layer on the outside of the myotomes. They develop into the adult distribution, concentrated at the midline of the flank near the skin, only after the gills and circulation become fully functional.


Author(s):  
Gertraude Wittig

The fine structure of insect hemocytes has been the subject of very few investigations. In particular, the hemocytes of Lepidoptera have received almost no attention. The study presented here was carried out on the armyworm, Pseudaletia unipuncta. Hemocytes of the larva were fixed 2 to 4 days after molt to the sixth instar and studied in ultrathin sections.Microplasmatocytes (Fig. 1) were the most important phagocytes of army-worm hemolymph. They were relatively small, spherical cells with a small, round or lobed nucleus. Distensions of the perinuclear cisterna (p) were frequent and sometimes continuous with the rough endoplasmic reticulum (e). The latter formed greatly distended cisternae which almost filled the whole cytoplasm. The cisternae contained an amorphous material which appeared to be condensed in certain sacs (at e). Mitochondria (m) were rare, and they had tubular cristae. Up to four Golgi complexes (g) were identified in a microplasmatocyte section. Structured granules (sg) were specific for this cell type. Microfibrils (f) traversed the whole cytoplasm but were most frequent around the nucleus (N) and under the cell membrane.


2000 ◽  
Vol 203 (7) ◽  
pp. 1201-1210 ◽  
Author(s):  
F. Lou ◽  
W. J. van Der Laarse ◽  
N.A. Curtin ◽  
R.C. Woledge

Oxygen consumption and heat production were measured during contraction and recovery of isolated, white muscle fibres from dogfish (Scyliorhinus canicula) at 19 degrees C. The contraction period consisted of 20 isometric twitches at 3 Hz; this was followed by a recovery period of 2 h without stimulation. We tested the hypothesis that recovery is wholly oxidative (not glycolytic) in these fibres. The following features support this hypothesis. (i) The ratio of total heat produced to oxygen consumed, 451+/−34 kJ mol(−)(1) (mean +/− s.e.m., N=29), was close to that expected for either the oxidation of carbohydrate, 473 kJ mol(−)(1), or the oxidation of fat, 439 kJ mol(−)(1). Even assuming the maximum value (95 % confidence limit) of the observed heat production, glycolysis could account for resynthesis of at most 18 % of the ATP used during the contractions. (ii) When the difference in rates of diffusion of oxygen and heat within the muscle are taken into account, the time courses of oxygen consumption and heat production match each other well during the entire recovery period. The efficiency of recovery (=energy used for ATP synthesis/energy available for ATP synthesis) was estimated from the results. This value, 84.0+/−20.1 % (mean +/− s.e.m., N=29), is relatively high and represents the first such measurement in functioning muscle.


1974 ◽  
Vol 61 (2) ◽  
pp. 331-343
Author(s):  
D. REES

1. The application of metabolic inhibitors to nerve-muscle synapses on ‘white’ and ‘red’ fibres in the retractor unguis muscles of P. americana and B. giganteus resulted in a dramatic increase in the spontaneous miniature potential discharge and was accompanied by a summation of the miniature potentials to form ‘composite’ potentials. 2. Axon terminals associated with ‘white’ muscle fibres responded faster to metabolic inhibitors than those axon terminals associated with ‘red’ muscle fibres. 3. Correlated ultrastructural and electrophysiological studies inferred that a tentative relationship existed between the miniature potential activities and synaptic vesicle distributions of the nerve-muscle synapses during the phases of metabolic inhibition.


1967 ◽  
Vol 15 (2) ◽  
pp. 93-103 ◽  
Author(s):  
CLARISSA H. BEATTY ◽  
GLAYDIS M. BASINGER ◽  
ROSE MARY BOCEK

The hydroxyproline (collagen) content of muscle in terms of wet weight was lowest at 90 days gestational age (rhesus monkey) and increased until birth. Histologic techniques also demonstrated a progressive increase in staining density for connective tissue with increasing fetal age. However, when expressed in terms of nitrogen content of muscle, the hydroxyproline concentrations were similar from the 90-day fetal through the 2-6-week infant series, and were consistently higher in rapidly growing as compared to adult muscle. The succinic dehydrogenase activity (soleus), on the basis of wet weight or of nitrogen, was lowest in the 90-day fetal series and reached a plateau by 120 days. The histochemical data indicated an increase in staining density for succinic dehydrogenase in muscle as the fetus matured. By 90 days gestational age, the hydroxyproline concentration of red muscle was lower as compared to that of white muscle, and this difference was also apparent histologically. The succinic dehydrogenase activity was higher in red as compared to white muscle at all ages, and histochemical differentiation was apparent at 120 days fetal age.


2008 ◽  
Vol 52 (No. 1) ◽  
pp. 12-20
Author(s):  
Z. Eliáš ◽  
S. Hluchý ◽  
J. Mlynek

The aim of this study was to investigate the histological structure of the longissimus muscle in pigs in relation to carcass value indicators. A total number of 16 pigs of about 101.28 kg average live weight were used. The animals were raised at a Fattening and Carcass Value Experimental Station (FCVES) of Slovak University of Agriculture in Nitra in equal conditions, receiving a standard diet fortified with vitamin-mineral mixture, and they were slaughtered in an experimental abattoir of FCVES. Samples from the musculus longissimus lumborum et thoracisi (MLLT) for histological evaluation were taken within 30 minutes post mortem, immediately frozen in liquid nitrogen and stored at a temperature of −20°C. In the experimental abattoir of FCVES feeding indicators, and indicators of meat quality and carcass value were examined. Samples were processed histochemically and single types of muscle fibres were differentiated according to reactions on SDH on the basis of Vacek’s (1974) method. Nikon microscopic system, Pixelink digital camera and LUCIA software for image analyses for the morphometric analysis of MLLT structure were used. The highest abundance of white and the lowest abundance of intermediate muscle fibres was obtained in the analyzed musculus longissimus lumborum et thoracisi of pigs. Red muscle fibre abundance was only slightly higher than intermediate muscle fibre abundance. Concerning the average muscle fibre diameter, the highest values in white and the lowest values in red muscle fibres were found. Positive correlations of white muscle fibre abundance with loin meat weight, thigh meat weight, carcass length, ribcase length, hot right half weight, valuable meatiness parts in kilograms, thigh weight, thigh percent in the half-carcass and MLLT area weight were obtained. In the case of all fat content and weight indicators negative correlations were obtained except loin fat weight. Red muscle fibre content showed positive correlations with shoulder fat weight, neck meat weight, neck fat weight, head weight, thigh fat weight, average backfat thickness and MLLT area. Correlation coefficients between white muscle fibre diameter and shoulder meat weight, thigh meat weight, carcass length, ribcase length showed weak positive correlations. An increase in the white muscle fibre diameter corresponds with an increase in loin meat weight, valuable meatiness parts in kg, valuable meatiness parts in percents, thigh weight, thigh percent in the half-carcass weight and MLLT area. Concerning the red muscle fibre diameter weak positive correlations were obtained in relation to neck meat weight, thigh meat weight, thigh weight and moderate positive correlations to shoulder meat weight, loin meat weight, valuable meatiness parts in kilograms and percents, thigh percent in half-carcass and MLLT area.


1992 ◽  
Vol 163 (1) ◽  
pp. 259-279 ◽  
Author(s):  
L. C. Rome ◽  
I. H. Choi ◽  
G. Lutz ◽  
A. Sosnicki

In this study, electromyography showed that scup can swim to a maximum speed of 80 cm s-1 with their red muscle whereas previous results showed that carp can swim to only 45 cm s-1. Our aim was to evaluate the adaptations that enable scup to swim nearly twice as fast as carp. Although we anticipated that, at their respective maximum speeds, the red muscle of scup would be shortening at twice the velocity (V) of carp muscle, we found that the values of V were the same (2.04 muscle lengths s-1). At any given swimming speed, V was higher in carp than in scup because carp had a larger sarcomere length excursion and higher tail-beat frequency. The smaller sarcomere excursion in scup is primarily associated with using a less undulatory style of swimming (i.e. with a smaller backbone curvature). This less undulatory style of swimming may be an important adaptation that not only reduces V but may also reduce drag. At their respective maximum speeds, however, the 28% lower sarcomere length excursion in scup is balanced by a 26% higher tail-beat frequency, giving an equal V to that of carp. Although the scup in this study were somewhat longer than the carp in the previous one (19.7 vs 13.4 cm), we believe that many of the observed differences are species-related rather than size-related. We also found that scup swam in a kinematically similar fashion at 10 degrees C and 20 degrees C. However, at 10 degrees C, the scup could swim to only 54 cm s-1 before recruiting their white muscle whereas, at 20 degrees C, they could swim to 80 cm s-1. The difference in speed of initial white muscle recruitment, as well as information on muscle mechanics, suggests that the scup compress their recruitment order into a narrow speed range at low temperatures, thereby recruiting more muscle fibres. Quantitative analysis of red muscle electromyograms in this paper supports this hypothesis.


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