Pectoralis Superficialis Research Articles

Electron microscopical and biochemical studies of the major pectoral muscles of bats

The major pectoral muscles (musculus pectoralis superficialis) of two species of bats ( Miniopterus schreibersi fuliginosus and Rhinolophus ferrumequinum nippon) were studied by electron microscope and quantitative determination of myoglobin were carried out. 1. 2. In the pectoral muscles of both species, numerous mitochondria and lipid droplets occur between myofibrils. 2. 3. The average myoglobin concentration is 5.58 mg/g in M. s. fuliginosus and 1.83mg/g in R. f. nippon. 3. 4. It is suggested that these differences are related to the physiological properties of the muscles needed for different types of flight.

Elevated cholesterol in tissues of chicken embryos with hereditary myotonic muscular dystrophy

The cholesterol content of muscle, liver, serum, and brain was examined both in embryos of chickens with hereditary muscular dystrophy and in normal control embryos between 9 and 16 days in ovo. The superficial pectoral muscles, which are severely affected by muscular dystrophy later in development, have a significantly higher cholesterol content than those of normal embryos at all ages examined. In contrast, the cholesterol content of thigh muscles that are not severely affected by the dystrophic process is no different from that of control embryos. The cholesterol contents of liver and serum from dystrophic embryos are also increased, but the cholesterol content of the brain is not. The increased cholesterol contents of liver and serum are due to proportionate increases of both free cholesterol and cholesteryl esters. In contrast, in superficial pectoral muscles the ratio of cholesteryl esters to free cholesterol is significantly increased. These data indicate that, in addition to the elevated cholesterol in the liver and serum of dystrophic embryos, the regulation of cholesteryl ester content in the dystrophic pectoral muscles is abnormal.

Improved method for cannulation of the right lymph duct in dogs.

We have developed a relatively simple technique for cannulating the right lymph duct in the dog. We have successfully cannulated 19 of 20 dogs and have obtained stable lymph flows for up to 6 h. We make a skin incision over the origin of the pectoralis superficialis muscle and extend it laterally and cephalically until it is parallel and lateral to the external jugular vein. Using the cephalic vein as a landmark, we identify the cervical lymphatic which lies deep to the external jugular vein. We trace the cervical lymphatic posteriorly to the lymphatic ampulla, which is located at the external jugular and axillary venous junction. The ampulla receives the cervical, axillary, and right lymph ducts. We place a ligature around the ampulla and tie it off, forming a lymphatic pouch and obstruction lymph flow into the vein. We then cannulate the cervical lymphatic and advance the catheter into the ampulla and tie it in place. All lymphatic branches draining into the ampulla, except the right lymph duct, are ligated, enabling us to collect lymph form only the right duct. The high success rate is due, we believe, to the fact that we approach the right duct high in the neck and cannulate via the cervical lymphatic. We avoid direct dissection over the right lymph duct, and usually we do not have to cannulate the right duct directly.

Effects on Feed Consumption and Egg Production of Coffee Bean Seed (Cassia obtusifolia) Fed to White Leghorn Hens

Coffee bean seed (Cassia obtusifolia) was ground and mixed in the feed at levels of 2,5, and 10% and fed to White Leghorn hens. Feed consumption and egg production were reduced by all three although more so at 5 and 10%. Feed consumption and egg production had not returned to control levels four weeks after the adulterated feed was suspended, though the response was more pronounced in the younger birds. The semitendinosus and pectoralis superficialis muscles were pale and edematous at postmortem examination of the birds, being most pronounced at the 5 and 10% levels.

鶏の脂肪組織および浅胸筋の脂肪酸組成に及ぼす給与脂肪酸の影響

無脂肪飼料およびそれにステアリン酸,リノール酸あるいはマーガリン酸を添加した飼料を鶏雛に給与し,その頸部脂肪組織および浅胸筋の脂肪酸組成に及ぼす給与脂肪酸の影響を調査した.頸部脂肪組織は34～62%の脂質を含有し,そのうちトリグリセリドが97～98%を占めていた.また脂肪酸を給与するとその脂肪酸は脂肪組織中に比較的多量分布し,またマーガリン酸給与はパルミトオレイン酸の分布値を低下させ,リノール酸給与はステアリン酸の分布値を増加させた.浅胸筋は1.3～1.7%の脂質を含有し,そのうちリン脂質が77～79%,遊離コレステリンが11～13%を占めていた.各脂質分画でリノール酸の給与はリノール酸の分布を多くし,マーガリン酸の給与によリマーガリン酸およびヘプタデセン酸が検出されたが,ステアリン酸の給与はステアリン酸の分布値に影響を与えなかった.浅胸筋脂質の大部分を占めるりん脂質では,ステアリン酸の給与によりオレイン酸が多くなり,リノール酸の給与はパルミチン酸およびオレイン酸の分布値を低下させ,ステアリン酸の分布値を高くした.またりん脂質中にはエイコサトリエン酸およびアラキドン酸が検出され,リノール酸の給与により前者は低く後者は高くなった.

Developmental Changes in the Composition and Function of Sarcoplasmic Reticulum

Abstract Developmental changes in the protein, phospholipid, cholesterol, and fatty acid composition of skeletal and cardiac microsomes were correlated with Ca2+ transport activity in chicken embryos and during the early postnatal period. In skeletal muscle microsomes isolated from leg, superficial pectoralis, or deep pectoralis muscles, the rapid increase in the rate and extent of calcium accumulation around the time of hatching was accompanied by increase in total and Ca2+-sensitive ATPase activity, the concentration of phosphoprotein intermediate and the amount of transport ATPase enzyme determined by gel electrophoresis. The increased enzyme content of the membrane is reflected in its increased density and a marked decrease in phospholipid to protein ratio with development. The concentration of phosphatidylcholine, phosphatidylethanolamine, phosphatidylserine, sphingomyelin, and phosphatidylinositol changed relatively little during the first 50 days of development but the appearance of calcium transport activity was accompanied by a marked decrease in the palmitate and increase in the linoleate content of membrane phospholipids and a decrease in cholesterol concentration. These changes were clearly apparent in purified sarcoplasmic reticulum membranes isolated by calcium loading or in less pure membrane fractions obtained by differential or sucrose gradient centrifugation. Corresponding but much less pronounced changes in the enzymatic activity of cardiac microsomes were observed during development. Although the observations are consistent with nearly all possible mechanisms of membrane assembly they may suggest that the phospholipid-rich membranes of embryonic muscle are gradually converted during development into calcium-transporting structures by stepwise insertion of the ATPase enzyme and other components of the transport system.

Antibiotic Growth Promotion: Effects of Zinc Bacitracin and Oxytetracycline on Live Weight and Weights of Selected Muscles of New Hampshire Cockerels

Two antibiotic feeding trials were conducted using New Hampshire cockerels. Zinc bacitracin was used at low (11 mg./kg. of feed) and at high (550 mg./kg. of feed) levels in one trial; oxytetracycline (at the same levels) was used in the other. Both levels of bacitracin caused significant increases in live weight; the high level of oxytetracycline depressed the growth rate at about two weeks of age.Under the allometric model, 1) a single equation sufficed to express the relationship between carcass weight and live weight for all six groups of birds; 2) high levels of either antibiotic led to smaller leg muscle per mass per unit body weight; 3) neither antibiotic had an effect on the growth of biceps brachii or superficial pectoral muscle up to 8 weeks of age; 4) bacitracin depressed the relative growth of the deep pectoral muscle; oxytetracycline did not.

Lipid composition and synthesis in the muscles of normal and dystrophic chickens.

The lipids of the superficial pectoral muscle of 5-week-old normal and dystrophic New Hampshire chickens were fractionated by thin-layer chromatography procedures. Total lipid in the dystrophic muscle was fivefold greater than in normal muscle with the triglycerides 15-fold greater and the phospholipids 1.5-fold greater (wet weight basis). The relative proportions of phospholipids were quite similar except for significantly less phosphatidylcholine and phosphatidic acid in the dystrophic muscle. In another study acetate-2-14C was injected intraperitoneally into normal and dystrophic chickens which were killed at various times up to 7 days after the administration. The dystrophic birds incorporated acetate-2-14C to a greater extent into total lipids, triglycerides, and phospholipids of the muscle than normal chickens. The turnover times for both triglycerides and phospholipids were much greater in dystrophic than in normal chickens with the triglycerides showing a longer time than the phospholipids. In vitro incubation of acetate-2-14C with muscle slices showed a greater rate of incorporation into lipid by dystrophic than by normal muscle. These results indicate that the difference in acetate incorporation between normal and dystrophic muscle was due to metabolism in the muscle itself and not entirely a result of mobilization of lipid from other tissues.

Organ and body mass changes in restrained and fasted domestic fowl.

SummaryOrgan and body mass changes in restrained adult, male domestic fowl were compared with tissue from control and fasted animals. Body mass loss rate in the restrained animals was 63.5% (p < .001) greater than in the fasted group, yet the two groups recovered at the same rate. Compared with controls and fasted animals, restrained fowl exhibited an increase in size of heart, lungs, kidneys, liver, and adrenals but a greater loss of spleen, superficial pectoral muscle, small intestine, and pancreas masses. Relative water content of organs generally increased in restrained and decreased in fasted animals. The data suggest that restraint—although accompanied by inanition—affects organ and body mass in the domestic fowl in a different way than does fasting.

Nitrogen Fraction Changes in Turkey Roasts During Latter Stages of Cooking

CERTAIN physical and sensory changes in dark and light meat from boneless turkey roasts were reported by Wilkinson and Dawson (1967). When cooked to temperatures from 60 to 88°C, light meat was more tender but less juicy than dark meat. Shear force for light meat also appeared to be adversely affected at the two extremes in temperature.Marion and Forsythe (1962) reported no changes in amino, TCA soluble, protein and total soluble nitrogen in pectoralis superficialis and biceps femoris muscles from turkeys during rigor; however, all values were higher in pectoralis superficialis than biceps femoris.Non-protein nitrogen in beef steaks was found to decrease 4 to 30 fold during cooking to 150°F. (65°C.) by Ginger et al. (1954). Husaini et al. (1950) reported that connective tissue in beef muscle, as represented by alkali insoluble protein, was related to tenderness; however, Wierbicki et al. (1954) reported that connective tissue did not .

Tenderness of Dystrophic Chicken Meat

THE occurrence of muscular dystrophy in chickens has been traced to an autosomal recessive gene (Asmundson and Julian, 1956, 1963). Several studies have been made at the University of California at Davis on the composition of the dystrophic chicken muscle (Jordan et al., 1959., 1964; Peterson et al., 1963; and Wilson et al., 1965). Fat content of the Pectoralis superficialis of dystrophic chickens increased abnormally as early as 15 weeks of age, and exceeded 20% by 78 weeks, compared to 1–2% for normal controls. Taurine and serine-ethanolamine-phosphate content of adult dystrophic chicken Pectoralis superficialis was more than 10 fold that of controls, and carnosine and anserine levels were less. The present report provides data on the relative tenderness of cooked dystrophic and normal muscle, corresponding values for the fat content and pH, and certain characteristics of the carcasses.A sample of 23 dystrophic [10 males, 13 females (Univ. of .

FISSION PRODUCT METABOLISM IN HENS AND TRANSFERENCE TO EGGS.

Groups of eight laying Single-Comb White Leghorn pullets were each administered the following fission products: strontium-89, yttrium-91, niobium-99, molybdenum-99, ruthenium-103, iodine-131, tellerium-132; cesium-134, barium-140, lanthanum-140, praseodymium-142, cerium-144, neodymium-147 or promethium-147 at levels selected to permit counting of tissues upon sacrifice 96 hr after dosing. Half the hens were administered the fission products intramuscularly (IM) while the other half received them orally. Whole blood, plasma, gastrocnemius muscle, superficial pectoralis muscle, liver, gall-bladder, kidney, lung, spleen, heart, brain, gizzard, tibia shaft, posterior portion of sternal crest, ovary, reproductive tract and eggs were analyzed for fission product content. The differences in fission product concentration in tissues and egg components between IM and oral routes were quite small for 134Cs, 89Sr and 131I. These same differences for the fission products increased in magnitude in the following order: 99Mo, 140Ba 132Te 142Pr, and 103Ru. Very little, if any, 91Y 95Nb, 140La 144Ce, 147Nd or 147Pm was found in the tissues and eggs from hens receiving these fission products orally. The fission products of cesium, tellurium, lanthanum, neodymium and molybdenum in poultry meat and iodine, cesium, tellurium, molybdenum, barium and strontium in eggs might be potential hazards to man consuming these from hens which ingested these fission products. This list would be extended if a parenteral contamination of poultry occurred.

LIPID COMPOSITION OF THE PECTORAL MUSCLES OF CHICKENS WITH INHERITED MUSCULAR DYSTROPHY.

Asmundson and Julian (1,2) reported the presence of a recessive autosomal gene (am) in New Hampshire chickens which produces in the homozygous bird a condition quite similar to certain forms of muscular dystrophy in man(3). The superficial pectoral muscles of such adult birds contained considerably more fat than those of normal birds (4,5). Elevated fat content has also been found in certain muscles of mice with muscular dystrophy by Shull and Alfm-Slater(6) and in some types of muscular dystrophy in man (3). This investigation was undertaken to determine the nature of the fat deposited intramuscularly in chickens with inherited muscular dystrophy. An increase in the triglyceride fraction and a decrease in the phospholipid fraction relative to other lipids constitute the major differences in the dystrophic muscle when compared with the normal muscle. Methods. Seven pairs of 36-week-old normal and muscular dystrophic female New Hampshire birds were used in the study. The animals were sacrificed and the left superficial pectoral muscles were excised, quick-frozen in a dry ice-acetone bath and stored at —20°C. They were thawed and used as needed. A 0.5-0.8 sample g of wet muscle was placed in a vacuum oven at 70° for 12 hours to determine the moisture content by weight difference. Protein was determined by the Kjeldahl method (N × 6.25) and hydroxyproline was determined by the technique of Neuman and Logan(7). The hydroxyproline content was used as a measure of collagen or connective tissue. The fat was extracted from the muscle by the CHCl3:CH3OH:H2O method of Bligh and Dyer(8). The CHCl3 layer containing the lipid, was evaporated in a 60° C water bath under a stream of N2. Approximately 70 mg of this fat was chromatographed on a 3.0 g silicic acid-Hiflo Supercell column (70: 30 w/w), and eluted by the scheme of Barron and Hanahan(9).

Fat deposition in musculature of the genetically dystrophic chicken.

SummaryGenetically dystrophic chickens contain significantly more crude fat in the superficial pectoral muscle (% of wet sample) than do normal chickens. An increased fat deposition is noted as early as 15 weeks of age and is associated with physical manifestation of dystrophy resembling certain muscular dystrophies in man. Females deposit more crude fat than males.