Diversity of native myosin and myosin heavy chain in fish skeletal muscles

• 1.1. Polymorphism of native myosin and myosin heavy chain (MHC) of fish skeletal muscles was analysed by pyrophosphate and SDS-gel electrophoreses.
• 2.2. Depending on the species, three or four myosin isoforms were detected in the white muscle, one or two isoforms in the pure red muscle, and four isomyosins were found in the red muscle composed of red and pink (intermediate) fibres.
• 3.3. It is suggested that all main types of fish muscle fibre (red, intermediate and white) differ in myosin isoform content.
• 4.4. Myosin heavy chain of the red muscle is a distinct protein from that of the white muscle. However, structural differences between these proteins vary among species.

     

Temperature acclimation in amphibians: Changes in lactate dehydrogenase activities and isoenzyme patterns in several tissues from adult Discoglossus pictus pictus (Otth.)

• 1.1. The effect of cold (8 ± 2°C) acclimation on the lactate dehydrogenase activities and isoenzyme patterns from sartorius muscle, liver, heart and brain of adult Discoglossus pictus pictus (Otth.) was studied.
• 2.2. Two groups of animals were studied: one set of animals was trapped in October and another set in December. In both cases some of the animals were sacrificed upon collection and some others subjected to 5 months of acclimation at 8 ± 2°C before being sacrificed for analysis.
• 3.3. A general trend towards a decrease in LDH specific activity was observed during cold acclimation. The magnitude of change, but not the direction, depends on both the tissue examined and the season at which the experiment was initiated.
• 4.4. A complex LDH isoenzyme reorganization was also found in liver, heart and brain. In liver from Experiment 1 and in heart from both experiments, a relative maintenance in M-type LDH activity during cold acclimation was observed. However, in brain there was a relative maintenance of LDH₃ activity in both experiments.
• 5.5. The low behavioral activity (and its metabolic consequences) and the existence of an intrinsic annual rhythm in D. pictus metabolism are suggested as responsible for the observed enzymatic changes.

     

Modification of glyceraldehyde-3-phosphate dehydrogenase,EC 1.2.1.12, isolated from rainbow trout during acclimation at 5 or 15°C—II. Biochemical characterization of G3PDH muscle isolates

• 1.1. G3PDH was isolated from the lateral muscle of rainbow trout (Salmo gairdneri) acclimated at 5°C (cold) and 15°C (warm).
• 2.2. No differences were found in muscle concentration, molecular weights, isoelectric focusing patterns, amino acid compositions or peptide maps between cold and warm isolates.
• 3.3. Cold and warm G3PDH contained mannose in variable concentration but no other prosthetic groups.

     

Temperature acclimation in respiratory and cytochrome c oxidase activity in common carp (Cyprinus carpio)

• 1.1. Common carp (Cyprinus carpio) exposed to experimental temperatures of 12, 18, 24, 30 or 36°C for a 4-week period were used to investigate the effect of temperature acclimation on the frequency of opercular movement (FOM), growth and cytochrome c oxidase (CCO) activity in heart, liver and muscle.
• 2.2. An exponential relationship between FOM and temperature after the first week (10₁₀ =1.76) disappeared after the second week.
• 3.3. The initially high FOM at temperatures of 30 or 36°C and the low FOM at 18 or 12°C changed over 4 weeks to approach the FOM of fish at 24°C.
• 4.4. This change in the relationship of FOM to temperature from highly dependent to independent appeared to be thermal compensation.
• 5.5. Heart and liver CCO activities were significantly affected by temperature, with the lowest activity at the approximate optimum temperature for growth, 24°C.
• 6.6. Highest CCO activities for heart and liver occurred at both the highest and lowest temperatures.
• 7.7. Among the three tissues, heart CCO activity was generally the highest and most affected by acclimation temperature.
• 8.8. Muscle tissue had the lowest CCO activity and was unaffected by temperature.
• 9.9. The high CCO activity at a cold acclimation of temperature 12°C was probably due to thermal compensation and the high activity at 36°C may have been a result of thermal stress.

     

Effects of temperature and metabolic inhibitors on contraction of anterior byssus retractor muscle of Mytilus

• 1.1. Anterior byssus retractor muscle of Mytilus (ABRM) was stimulated to contract by ACh (acetylcholine) and effects of temperature (5–30°C), FDNB (1-fluoro 2,4 dinitro-benzene) and IAA (iodoacetic acid) on tension response were examined.
• 2.2. Isometric tension was highest at the temperature range of 10–20°C and decreased at higher and lower temperature than that range.
• 3.3. The rate of tension decay after washing of ACh was accelerated by the increase of temperature.
• 4.4. Tension redevelopment after release of 1 % during contraction was much smaller at 5°C than at 20°C.
• 5.5. Tension development by ACh and the rate of tension decay after washing of ACh were remarkably decreased by the treatment of FDNB or IAA.
• 6.6. The above results were discussed from the viewpoint that energy metabolism might be related to catch.

     

Heart rates of adult red-spotted newts,Notophthalmus viridescens in air and submerged in normoxic and hypoxic water at different temperatures

• 1.1. Heart rates of adult aquatic red-spotted newts can be conveniently recorded using an impedance pneumograph.
• 2.2. Heart rates decrease linearly with decreasing temperature.
• 3.3. Submergence in normoxic and hypoxic water at 10°, 15°, and 20°C results in bradycardia which is more pronounced in hypoxic water.
• 4.4. At 5°C one newt exhibited the above pattern, but bradycardia was not exhibited by the other newt during normoxic submergence.
• 5.5. Diminishing heart rates are probably due to oxygen deficiency, not immersion alone.
• 6.6. Recovery from bradycardia in air is rapid and not linked with resumption of aerial breathing.

     

Influence of environmental factors on the deep and skin temperature in the European bison,Bison bonasus (L.)

• 1.1. In 43 European bison divided into three groups (Group A, 3–8-month-old calves; Group B, 18-month-7-year-old young bison; Group C, 12–24-year-old bison) the rectal, humerus region and abdomen region temperatures were measured.
• 2.2. The experiments were carried out in winter months, from mid-December to mid-March.
• 3.3. The mean rectal temperatures changed from 38.55°C in calves to 38.15°C in the oldest bison.
• 4.4. The mean temperatures of the humerus region changed from 20.69°C in calves to 21.49°C in older bison.
• 5.5. The mean temperatures of the abdomen region changed from 20.79°C in calves to 22.17°C in older bison (Gr. B).
• 6.6. The cluster analysis divided the bison into four groups named hot, warm, cool and cold bison.
• 7.7. Only air temperature measured 2 m above the ground and snow cover influenced the integrated bison temperature. Age, sex and mass as well as some environmental factors had no influence.
• 8.8. Measurements made 1 to nearly 4hr after a bison's death showed a drop in rectal temperature and mostly increases in temperatures of the humerus and abdomen regions.

     

Effect of temperature on muscle contractility of the eurythermic lizard Leiolopisma zelandica

• 1.1. The isometric twitch tension development (contractility) of the puboischiotibialis muscle of the eurythermic skink Leiolopisma zelandica was determined over the range 0–45°C.
• 2.2. Mean muscle tensions of at least 70% of maximum tension occur over the range 5–40°C, falling to 51 and 33% at 0 and 45°C respectively.
• 3.3. Contraction and relaxation times of the twitches measured between 0 and 20°C indicate marked temperature sensitivity below 5°C commensurate with the conspicuous decrease in locomotivity.

     

Social facilitation of reduced oxygen consumption in Mus musculus and Meriones unguiculatus

• 1.1. The short-term resting rates of oxygen consumption of laboratory white mice (Mus musculus) and Mongolian gerbils (Meriones unguiculatus) were measured by closed system manometry.
• 2.2. Metabolic rates of animals tested individually were compared to those of huddled trios and trios in which the animals were tested simultaneously but prevented from physical contact (separated trios) at temperatures ranging from 9–25° C.
• 3.3. Rates of increase of weight-specific resting metabolism were greatest for animals tested individually.
• 4.4. There was no significant difference in the rates of increase of oxygen consumption between huddled and separated trios in cither species.

     

The effect of hypoxia on carbohydrate metabolism in flounder (Platichthys flesus L.)—I. Utilization of glycogen and accumulation of glycolytic end products in various tissues

• 1.1. Resting oxygen consumption at 10°C did not change from normoxia (150 mm Hg) down to an oxygen tension of 55 mm Hg for the flounder, Platichtys flesus.
• 2.2. Flounders exposed to hypoxia showed increased levels of blood glucose and lactate, dependent on the degree of hypoxia.
• 3.3. Due to hypoxia glycogen was depleted in the liver and swimming muscle but in the heart there was no significant change.
• 4.4. Liver glucose increased after 7 hr of hypoxia. Heart and muscle glucose did not change but the absolute glucose concentration in the heart was five times higher than in the muscle.
• 5.5. There is a transient accumulation of lactate in heart, liver and kidney after 7 hr of hypoxia while lactate accumulation in the swimming muscle is significant only after 21 hr of hypoxia.
• 6.6. Succinate only accumulated in the liver while alanine accumulated in muscle, heart and liver.

     

Myofibrillar proteins in skeletal muscles of parr,smolt and adult atlantic salmon (Salmo salarl.). Comparison with another salmonid,the arctic charr Salvelinus alpinus (l.)

The heavy and light subunits of myosin from white and red muscles of Atlantic salmon parr, smolt and adult individuals were analyzed by SDS-PAGE and two-dimensional electrophoresis. Tropomyosin was identified by comigration with rat tropomyosins in two-dimensional gels in the presence and absence of urea. These myofibrillar proteins were compared to those of Arctic charr.

• 1.1. The myosin heavy chain from Atlantic salmon red muscles was associated with two types of light chain, 1S and 2S, that comigrated with the light chains 1S and 2S of Arctic charr.
• 2.2. As in the Arctic charr, four myosin light chain spots were detected in white muscles: two fast myosin light chains type 1, one of which comigrated with its analogous in the Arctic charr; one fast myosin light chain type 2, differing slightly in isoelectric point from that of Arctic charr; and one fast myosin light chain type 3 with higher electrophoretic mobility than that of Arctic charr.
• 3.3. Three tropomyosin spots were detected. White muscles contained only one type of β-tropomyosin and red muscles two types of α-tropomyosin. These three tropomyosin spots comigrated with those of Arctic charr.
• 4.4. Two myosin heavy chain bands were observed in red muscles of salmon parrs but only one in the rest of the red muscles analyzed.
• 5.5. Only one myosin heavy chain band was detected in white muscles by SDS-glycerol-polyacrylamide gel electrophoresis. Alfa-chymotryptic peptide mapping of these white myosin heavy chain bands revealed differences attributed to the presence of a new type of myosin heavy chain first detected several months after smoltification.

     

Characterization of two distinct latent proteinases associated with myofibrils of crucian carp (Carassius auratus cuvieri)

:

• 1.1. Enzymatic properties of two distinct proteinases tightly associated with crucian carp myofibrils were characterized.
• 2.2. These proteinases were latent but activated at 50 and 60°C, respectively.
• 3.3. The optimum pH of 50°C-proteinase was neutral-alkaline, while that of 60°C-proteinase was weak acid-neutral pH.
• 4.4. Both proteinases required more than 1% NaCl for the activity, but 50°C-proteinase was partially inhibited at higher concentrations of NaCl.
• 5.5. Both proteinases were regarded as trypsin-like proteinases belonging to a serine proteinase family, but only 60°C-proteinase was sensitive to urea, n-butanol and iso-propanol.

     

Modification of glyceraldehyde-3-phosphate dehydrogenase,EC 1.2.1.12, isolated from rainbow trout during acclimation at 5 or 15°C—I. Changes in the activity of individual muscle isolates as evidence for variable adaptive responses

• 1.1. The mean K_m and V_max values for G3PDH isolated from the lateral muscle of cold-adapted (5°C) rainbow trout, Salmo gairdneri, were twice those of enzyme from warm-adapted (15°C) trout when assayed at 7°C but not at any other temperature.
• 2.2. The entropy of activation of warm enzyme was about 3 times that of cold enzyme. However, enthalpy or free energy of activation among acclimation groups differed less or not at all.
• 3.3. Individual G3PDH isolates within either adaptation group differed in kinetic characteristics.

     

Seasonal changes of circulating blood parameters in the grass snake Natrix natrix natrix L.

• 1.1. Seasonal changes of circulating blood parameters of Natrix n. natrix were evident and involved both sexes to the same extent.
• 2.2. A significant decrease in red cell count, haematocrit and haemaglobin concentration in the mating period, and an increase in those parameters and mean cell volume in autumn were observed, and haemodilution during winter torpor.
• 3.3. The changes during the breeding season had probably a hormonal background; in winter, they resulted first of all from a decreased erythropoietic activity and, to a lesser extent, from an increased red blood cell breakdown rate. However, the possibility that some erythrocytes were withdrawn from the circulation cannot be excluded.
• 4.4. Winter lymphocytopenia, eosinocytopenia and neutrophilic granulocytosis in females during egg laying were expressions of changes of leucocyte formula.
• 5.5. Seasonal cyclicity was found only with respect to the white cell count in males and the eosinophile fraction in males and females.
• 6.6. Probable reasons for, and mechanisms of the changes in blood composition are discussed.

     

Proteolysis of skeletal muscle in yellowfin tuna (Thunnus albacares): Evidence of calpain activation

• 1.1. White muscle of yellowfin tuna is subject to a form of deterioration known as “burnt tuna”.
• 2.2. TEM and SDS-PAGE were used to quantify cellular differences in deteriorated white muscle of yellowfin tuna.
• 3.3. Electron micrographs showed a significant loss of Z-disc integrity and an increase in intracellular edema in burnt tuna.
• 4.4. Electrophoresis established that a specific doublet of proteins, 42 kD and 46 kD was lost.
• 5.5. Proteolysis of isolated myofibrils incubated in calpain (EC 3.4.22.17) was greatest at pH 7.5 and was selective for intermediate molecular weight proteins.
• 6.6. This evidence suggests that burnt tuna is a specific and limited proteolysis of myofibrillar structural proteins characteristic of calpain proteolysis.

     

Running performance of the thirteen-lined ground squirrel,the eastern chipmunk and the albino Norway rat

• 1.1. The procedure used to compare the forced running performance of three rodent species was the number of electrical stimuli required each minute to keep the animals running.
• 2.2. During running trials, ground squirrels, Spermophilus tridecemlineatus, required fewer stimuli than white rats. Squirrels ran 12.4 ± 6.9 (2 SE) min before requiring stimulation vs 3.1 ± 1.4 min for rats.
• 3.3. Total oxygen consumption during the running period was significantly higher for ground squirrels than white rats, 4.70 ± 0.36 and 4.18 ± 0.38ml O₂/g/hr, respectively.
• 4.4. Heart weight/body weight ratios were significantly higher for the ground squirrels than the white rats.
• 5.5. No differences were noted between ground squirrels and chipmunks other than those which could be accounted for by body weight differences.

     

Cardiac frequency compensation responses of adult blue crabs (Callinectes sapidus Rathbun) exposed to moderate temperature increases

• 1.1. Cardiac frequency patterns of Callincctes sapidus Rathbun were used to evaluate potential thermal stress after exposure to 5°C increases over a range of acclimation temperatures from 5° to 30°C.
• 2.2. An acclimated rate-temperature curve (R-T curve), acute R-T curves of the stabilized rates at the increased temperatures and Q₁₀ temperature coefficients were used to assess the significance of the changes in rate frequency.
• 3.3. The acclimated R-T curve showed that blue crabs go through a series of seasonal adaptation types characterized by a plateau of perfect adaptation for both cold and warm adapted organisms. Paradoxical adaptation occurred between the transition from cold to warm acclimation temperatures.
• 4.4. The acute R-T curves showed that cardiac frequency was highly responsive to a 5°C increase when the organisms were acclimated to low temperatures.
• 5.5. The Q₁₀'s of the acute R-T curves at the warm acclimation temperatures approximated those values derived for the acclimated R-T curve.
• 6.6. This suggests that the temperature increase had a negligible effect on the warm adapted crabs, that is, little or no thermal stress occurred.

     

Active transport of d-glucose in intestinal segments,in vitro,of the scup,Stenotomus versicolor and the puffer,Spheroides maculatus

• 1.1. Active transport of d-glucose was shown using intestinal sac preparations, in vitro, made from two marine fish, the scup, Stenotomus versicolor and the puffer, Spheroides maculatus.
• 2.2. Differences in absorption characteristics were evident in populations from year to year.
• 3.3. Anaerobiotic conditions, i.e. 100 per cent nitrogen gassing of the incubation medium, inhibit the active transport of d-glucose in scup and puffer intestine.
• 4.4. Phlorizin, 5 × 10⁻⁴ M, inhibits the active transport of d-glucose in scup intestine.
• 5.5. Intestinal transmural glucose transport mechanisms operate well at incubation temperatures, 20°–27°C, i.e. temperatures close to habitat and holding tank temperatures, whereas movement of the sugar against a concentration gradient is interrupted at higher incubation temperatures, 29° and 30°C.
• 6.6. Detailed comparison of procedures and results with those used by other workers in the field of in vitro intestinal absorption of poikilotherms suggests that aerobic metabolism may not be a uniformly significant energy source in intestinal active transport.

     

Analysis of clotting defects in diseased lobsters—I. Alterations in blood parameters

• 1.1. In gaffkemic lobsters kept at 15°C. drastic declines in the hemocyte number and clotting ability occur.
• 2.2. In animals kept at 10°C, although some clotting defects rapidly occur, a high number of amoebocytes is found. Clotting ability reappears after 5 days.
• 3.3. The proportion of each type of hemocyte changes. Numerous hemocytes show morphologic altered features.
• 4.4. Dorsal hematopoietic tissue is as in control lobsters.
• 5.5. Total protein contents are similar in bacteremic or control lobster hemolymphs.

     

Arginase activity in different fish species and tissues

• 1.1. Arginase activity was measured in different tissues from eight species of fish.
• 2.2. Spur dogfish showed a very high arginase activity compared with the other species analysed.
• 3.3. The activity in teleosts was mainly found in tissues of high metabolic activity (liver, kidney and red muscle).