Seal Muscle Research Articles

Myoglobin expression: early induction and subsequent modulation of myoglobin and myoglobin mRNA during myogenesis.

We showed that myoglobin gene transcription and the appearance of myoglobin occur very early in myogenesis, in both humans and mice. In contrast to the contractile protein genes, there is a subsequent increase of 50- to 100-fold in myoglobin mRNA and protein levels during later muscle development. Myoglobin and myoglobin mRNA are present at elevated levels in fetal heart and are also detectable at low levels in adult smooth muscle. The absolute level of myoglobin mRNA in highly myoglobinized seal muscle is very high [2.8% of the total population of poly(A)+ RNAs]. Levels of myoglobin in seal skeletal muscle and in various human muscle types appear to be determined by the size of the myoglobin mRNA pool. In contrast, low levels of myoglobin in mouse skeletal muscle are not apparently correlated with low levels of myoglobin mRNA. As expected from the early appearance of myoglobin mRNA in embryonic skeletal muscle, both rat and mouse embryonic myoblasts accumulate myoglobin mRNA on fusion and differentiation in vitro.

Cadmium and copper levels in seals, penguins and skuas from the Weddell Sea in 1982/1983

Samples of muscle, liver and kidney of Weddell and crabeater seals, Adelie and emperor penguins, and McCormick's skuas collected in the Weddell Sea in the summer 1982/83 were analysed for cadmium and copper. In general, the study aimed at contributing to the establishment of base-line data on potential pollutants in Antarctic ecosystems. In particular, it aimed at increasing the amount of data on Cd and Cu levels in the same species that that had been collected and analysed two years eralier, thus improving the possibility of statistical analyses into relationships between metal contents and biological parameters or sampling-sites of the animals, but the data basis is still too small for the letter purpose. In all species together, concentration ranges (on dry weight basis) were 0.16–0.77, 3.7–96.8 and 15.6–491 mg cadmium and 1.6–21.4, 14.9–149 and 12.6–47.7 mg copper per kg in muscles, livers and kidneys, respectively. The relatively high levels of both metals in all species analysed, in connexion with the available literature, suggest that levels in marine mammals and birds can only, if at all, to a minor extent reflect differences in environmental concentrations of these metals.

Isozymic Differentiation of Cardiac and Muscle Pyruvate Kinase in the Ringed Seal Phoca hispida

To determine whether the unusual capacity of muscle of diving mammals to undergo extended periods of anaerobiosis is due to the expression of specialized forms of the rate-limiting enzymes of glycolysis, we examined the isozymic nature of the pyruvate kinase expressed in various tissues of the ringed seal Phoca hispida. Our electrophoretic results indicate that heart and skeletal muscle contain different forms of pyruvate kinase. Both of these forms are distinct from the cathodally migrating type K isozyme in the liver. Kinetic results show that both these forms are distinct from other mammalian type M pyruvate kinases in having an acid pH optimum and a sensitivity to alanine inhibition. The affinity of the seal muscle pyruvate kinase for phosphoenolpyruvate (PEP) is lower than that of the heart form or of other mammalian type M isozymes. While the seal heart isozyme shows a decrease in affinity for PEP with a decrease in temperature, the PEP affinity of the muscle form is independent of temperature. This permits a more constant enzyme activity in the more heterothermic muscle. Muscle pyruvate kinase, with its acid pH optimum, lowered affinity for PEP, and increased sensitivity to alanine inhibition, is well suited for a tissue which undergoes prolonged anaerobic periods and then switches to aerobic utilization of lipids. We conclude that the differentiation of this distinct muscle pyruvate kinase is a special adaptation which may partially account for the ability of seal muscle to withstand considerable periods of anaerobiosis.

Nature of Adenosine Triphosphatase Accelerating Peptide from Hydrolysate of Fur Seal Muscle

Ultrafiltered fur seal muscle hydrolysate was divided into eleven fractions by gel filtration on Sephadex G-15. One of the fractions (Fraction G9) accelerated the ATPase activity of carp myosin B to a rate about two-fold faster than that of the control. Fraction G9 showed a single ninhydrin spot in its silica gel thin layer chromatograph, and gave a positive test for tryptophan by the p-dimethylaminobenzaldehyde method, while tests for tyrosine, and for arginine were negative. The ion exchange amino acid analysis of its acid hydrolysate showed a predominant content of lysine, nearly equivalent to the amount of tryptophan determined from its UV absorbancy and the p-dimethylaminobenzaldehyde method. The N-terminal amino acid analysis gave di-DNP-Lys as the sole DNP-amino acid. The structure of the ATPase accelerating peptide fraction, Fraction G9, was deduced to be Lys-Trp.

An Electromyographic Investigation of the Perioral Musculature in Class II Division 1 Malocclusion

The changes in lip activity associated with retraction of the upper labial segment during treatment of Class II division 1 malocclusion were investigated electromyographically. In the lip seal position muscle activity of the circumoral muscles was much reduced after treatment, but the amount of reduction appeared to be unrelated to the amount of incisor retraction. In some cases lips which were judged to be incompetent before treatment were competent after treatment. Activity in the suprahyoid muscle group associated with upper incisor inclination and overjet when the lips were sealed was eliminated during swallowing.

Isolation of ATPase accelerating peptides from fur seal muscle hydrolysate.

In the previous paper, the ATPase accelerating peptides were found to be distinct from the vasoactive and vasodilatory peptides in the same hydrolysate. This work was undertaken to isolate the ATPase accelerating peptide from the fur seal muscle hydrolysate. Minced skeletal muscle of fur seal was digested with protease and the resulting hydrolysate was fractionated with 90%ethanol. The obtained precipitate and the effective agent was fund only in the precipitate. By continuous flow electrophoresis, the was divided into five major fractions, each of which was examind for accelerating effect on ATPase by two different methods, i.e., inorganic phosphate determination and pH-stat method. Among the five electrophoretic fractions, the second fraction E2 migrating to the anode showed the best accelerating effect, while the other fractions were less accelerative. Also the possible of Ca ions was refuted. E2 was also examined for physiological activity by kymographic recording of the contraction of rat intestine smooth muscle and showed an effect which is revealed by a contraction preceded by a slight relaxation. Thin layer chromatography revealed that there are more than two peptide components in fraction E2.

Fractionation of ATPase accelerating peptides from fur seal muscle hydrolysate.

Fractionation of ATPase accelerating peptides from fur seal muscle hydrolysate.

Stimulating effect of fur seal muscle hydrolysate peptides on contractile activity of actomyosin.

This work was undertaken as an introductory step for isolating the biologically active components of the hydrolysate preparation of fur seal skeletal muscle proteins which contain some vasoactive factors as reported previously. This study was carried out with 2 preparations obtained at different fractionation stages, i.e., “unfractionated mixture” and “lyophilized powder”, the latter constituting the second fraction of gel filtration (Sephadex G-25) of the former. The 2 preparations differed in peptide composition, because their relative biuret, ninhydrin and ultraviolet absorption values differed respectively. By paperand thin layer-chromatography, peptide mapping as well as ion exchange column chromatography, both preparations were found to contain more than 22 peptide components, though the lyophilized powder had less than the other. The lyophilized powder showed an accelerating effect on the rates of both superprecipitaion (0.1 ionic strength, pH 7.0) and ATPase activity (0.15 ionic strength, pH 6.4) of fish actomyosins. The acceleration was also positive when Ca and Mg ions were removed by adding GEDTA or EDTA. These effects seem to be involved in the vasoactive and vasodilatory function of the fur seal peptide preparation.

Mercury in Seals, Terrestrial Carnivores, and Principal Food Items of the Inuit, from Holman, N. W.T.

Total mercury analyses were made on liver and muscle of ringed and bearded seals, of caribou, and on muscle of Arctic char (the principal items in the diet of local people), of Arctic fox and sledge dogs (which feed mostly on ringed seal) and on wolves (predacious on caribou). About half of the 123 samples were also analyzed for methyl mercury, and some for selenium.Ringed seals showed mean total mercury levels of 27 ppm in liver and 0.73 in muscle. Bearded seals showed 143 in liver and 0.53 in muscle. In the livers, methyl mercury was a small fraction of the total, being 5.6% in ringed and 0.38% in bearded seals. There were positive and significant correlations of mercury content with age and body weight. In Arctic char, mean total mercury was 0.049 ppm, and in caribou 0.20 in liver and 0.017 in muscle. In Arctic fox, values for liver and muscle were 0.77 and 0.32, and in sledge dogs 11.5 and 0.79 ppm.Seals form only part of the diet of the local people. Blood mercury levels have been reported for this community as being above average though not dangerously so. A change in diet, such as increased consumption of seals, might change this.

Tissue PO2 in normal and denervated cat skeletal muscle.

ARTICLESTissue PO2 in normal and denervated cat skeletal muscleWJ Whalen, P Nair, D Buerk, and CA ThuningWJ Whalen, P Nair, D Buerk, and CA ThuningPublished Online:01 Dec 1974https://doi.org/10.1152/ajplegacy.1974.227.6.1221MoreSectionsPDF (1 MB)Download PDF ToolsExport citationAdd to favoritesGet permissionsTrack citations ShareShare onFacebookTwitterLinkedInWeChat Back to Top Next Download PDF FiguresReferencesRelatedInformation Cited ByQuantitative Assessment of Blood Lactate in Shock: Measure of Hypoxia or Beneficial Energy SourceBioMed Research International, Vol. 2020August Krogh's theory of muscle microvascular control and oxygen delivery: a paradigm shift based on new data12 September 2020 | The Journal of Physiology, Vol. 598, No. 20Edward F. Adolph Distinguished Lecture. Contemporary model of muscle microcirculation: gateway to function and dysfunctionDavid C. Poole14 October 2019 | Journal of Applied Physiology, Vol. 127, No. 4Skeletal muscle interstitial O 2 pressures: bridging the gap between the capillary and myocyte10 October 2018 | Microcirculation, Vol. 26, No. 5Skeletal muscle microvascular and interstitial PO2 from rest to contractions30 January 2018 | The Journal of Physiology, Vol. 596, No. 5Arteriolar oxygen reactivity: where is the sensor and what is the mechanism of action?21 July 2016 | The Journal of Physiology, Vol. 594, No. 18Measuring Intracellular Oxygenation with Myoglobin MRS10 September 2015Effects of perfluorocarbon emulsions on microvascular blood flow and oxygen transport in a model of severe arterial gas embolismJournal of Surgical Research, Vol. 187, No. 1Skeletal muscle capillary function: contemporary observations and novel hypotheses10 October 2013 | Experimental Physiology, Vol. 98, No. 12Dynamics of muscle microcirculatory and blood-myocyte O2 flux during contractions1 March 2011 | Acta Physiologica, Vol. 202, No. 3Phosphorescence quenching microrespirometry of skeletal muscle in situAleksander S. Golub, Michael A. Tevald, and Roland N. Pittman1 January 2011 | American Journal of Physiology-Heart and Circulatory Physiology, Vol. 300, No. 1Local Regulation of Microvascular Perfusion1 January 2011Blood flow and metabolic regulation in seal muscle during apneaJournal of Experimental Biology, Vol. 211, No. 20Local Regulation of Microvascular PerfusionIn vivo Tissue pO 2 Measurements in Hamster Skinfold by Recessed pO 2 Microelectrodes and Phosphorescence Quenching Are in Agreement26 January 2010 | Microcirculation, Vol. 5, No. 2‐3Capillary blood flow and tissue metabolism in skeletal muscle during sympathetic trunk stimulationMiklós Pál, András Tóth, Peipei Ping, and Paul C. Johnson1 February 1998 | American Journal of Physiology-Heart and Circulatory Physiology, Vol. 274, No. 2Comparing Tissue PO2 Measurements by Recessed Microelectrode and Phosphorescence QuenchingOxygen sensitivity of mitochondrial metabolic state in isolated skeletal and cardiac myocytesKeith Neu Richmond, Steven Burnite, and Ronald M. Lynch1 November 1997 | American Journal of Physiology-Cell Physiology, Vol. 273, No. 5Microelectrode Studies of Facilitated O2 Transport Across Hemoglobin and Myoglobin LayersAn examination of the measurement of flow heterogeneity in striated muscle.Circulation Research, Vol. 60, No. 1Autoregulation of blood flow.Circulation Research, Vol. 59, No. 5Microcirculatory responses to carotid sinus nerve stimulation at various ambient O2 tension in the rabbit tenuissimus muscleMicrovascular Research, Vol. 30, No. 3Blood flow in the rabbit tenuissimus muscle Influence of preparative procedures for intravital microscopic observationActa Physiologica Scandinavica, Vol. 114, No. 1Influence of oxygen on perfused capillary density and capillary red cell velocity in rabbit skeletal muscleMicrovascular Research, Vol. 19, No. 2Oxygen requirement for prostaglandin biosynthesisProstaglandins and Medicine, Vol. 1, No. 2Relative importance of tissue oxygenation and vascular smooth muscle hypoxia in determining arteriolar responses to occlusion in the hamster cheek pouch.Circulation Research, Vol. 41, No. 4Hypoxia in skeletal muscle at rest and during the transition to steady workMicrovascular Research, Vol. 13, No. 3Oxygen pressure in small lymphaticsPflügers Archiv European Journal of Physiology, Vol. 366, No. 1The effect of oxygen on arteriolar red cell velocity and capillary density in the rat cremaster muscleMicrovascular Research, Vol. 12, No. 1 More from this issue > Volume 227Issue 6December 1974Pages 1221-1225 Copyright & PermissionsCopyright © 1974 by American Physiological Societyhttps://doi.org/10.1152/ajplegacy.1974.227.6.1221PubMed4440766History Published online 1 December 1974 Published in print 1 December 1974 Metrics

The harp seal, Pagophilus groenlandicus (Erxleben, 1777). XXV. Ultrastructure and metabolic adaptation of skeletal muscle.

An electron microscopic study of the structure of three skeletal muscles, pectoralis major, psoas, and longissimus dorsi, of the harp seal (Pagophilus groenlandicus) was carried out. Two types of fiber, the dark and the light comparable to the red (type 1) and the white (type 2) of other vertebrate skeletal muscles, were recognized while a third, the intermediate type, could be clearly distinguished only in the pectoralis major. All the fiber types contained considerable amounts of glycogen, while large aggregations of mitochondria and lipid droplets were seen only in the dark fibers.The intermyofibrillar matrix in the fibers of the pup (< 3 months) muscle was found to be more extensive than that of the adult muscle. The dark fibers in M, longissimus dorsi of both the pup and the adult appeared to have higher mitochondrial density than those of the other two muscles studied, thereby indicating that this muscle had a greater capacity for aerobic metabolism than M. psoas, which in turn had a larger population of mitochondria than M. pectoralis major. Though the presence of large mitochondrial aggregations and lipid droplets suggests the possibility of fat being used as fuel for muscular energy, it is postulated that the seal muscle is basically geared for anaerobic use of carbohydrate as an adaptation for the animal's diving habit. However, aerobic metabolism of carbohydrate and of a limited amount of fat may be used during surface swimming. It is also suggested that the mitochondrial aggregations and lipid droplets in the dark fibers of both adult and pup muscles represent an adaptation for thermogenesis comparable to that of the brown adipose tissue.

Strontium-90 and cesium-137 levels in tissues of fin whale (Balaenoptera physalus) and harp seal (Pagophilus groenlandicus).

90Sr and 137Cs were determined in 11 different tissues of the fin whale and 2 different tissues of the harp seal. Muscle tissue in most instances contained more 137Cs than did the other tissues that were examined. The average concentration of 137Cs in whale muscle was 4.5 pCi/g ash and in adult seal muscle was 2.5 pCi/g ash. The highest concentration (3.5 pCi/g ash) of 90Sr was found in whale blubber.

オットセイの骨格筋に存在する新生理活性ペプチッド様物質

The presence of a new biologically active peptide which has been named callopeptide by the authors was presumed in the digested muscle of fur seal as follows: Skeletal muscle brei including a small portion of bone or internal organs was digested by protease after eliminated fats and oils. Ethanol was added to the digested muscle, the soluble portion obtained at alcohol concentration of 60 to 80 percent passed through a column of Sephadex G-25 after concentrated under reduced pressure to remove the alcohol, and the effluents were divided into four fractions as in Figs. 1 and 2. It was observed that the second fraction develops an intense color by biuret reaction and shows the presence of 12 unknown peptides and small amounts of free amino acids on the chromatogram of amino acid analysis using an analyzer (Table 4). When the test animal (rabbit, cat, etc.) was affected with an aliquot of the second fraction, a strong capillary vasodilatory effect was observed which was disappeared by the complete hydrolysis of this fraction. The biological actions of the fraction are, however, differed from those of vasoactive peptide for instance, bradykinin as shown in Tables 1 and 2, and it was presumed that the digested fur seal muscle contains a new type of biologically active peptide.

The postmortal formation of lactic acid in the muscles of seals, ducks and hens

The postmortal formation of lactic acid in the muscles of seals, ducks and hens