Goat Muscle Research Articles

POSTMORTEM CHANGES IN MYOFIBRILLAR PROTEINS OF GOAT SKELETAL MUSCLES

Postmortem changes at 5C in myofibrillar proteins of longissimus dorsi (LD), biceps femoris (BF), semimembranosus (SM) and semitendinosus (ST) muscles and myofibrillar structure of LD muscle of goat were investigated. Muscle samples were immediately collected after killing, and from carcasses stored at 5C for 3, 6, 9, 12 and 20 days. The sodium dodecyl sulfate-polyacrylamide gel electrophoresis of myofibrils indicated the appearance of a 30 kDa component, depending on the type of the muscles. A new 55 kDa component appeared in BF and SM muscles during postmortem. Titin I and nebulin also disappeared during storage. The disappearance of titin 1 and nebulin and the appearance of a 30 kDa component were confirmed by Western blot analysis. The Transmission Electron Microscopy studies showed that after 3 days postmortem, Z-disks stayed unaltered. After 6 days postmortem, a little ultrastructural alteration was observed, and at 12 days postmortem a considerable degradation of Z-disk ultrastructure was shown. The Z-disk degradation, which results in the fragmentation of myofibrils and the appearance of 30 kDa components, is the major change observed in goat skeletal muscles during postmortem.

3D microenvironment as essential element for osteoinduction by biomaterials

In order to unravel the mechanism of osteoinduction by biomaterials, in this study we investigated the influence of the specific surface area on osteoinductive properties of two types of calcium phosphate ceramics. Different surface areas of the ceramics were obtained by varying their sintering temperatures. Hydroxyapatite (HA) ceramic was sintered at 1150 and 1250 °C. Biphasic calcium phosphate (BCP) ceramic, consisting of HA and beta-tricalcium phosphate ( β-TCP), was sintered at 1100, 1150 and 1200 °C. Changes in sintering temperature did not influence the chemistry of the ceramics; HA remained pure after sintering at different temperatures and the weight ratio of HA and β-TCP in the BCP was independent of the temperature as well. Similarly, macroporosity of the ceramics was unaffected by the changes of the sintering temperature. However, microporosity (pore diameter <10 μm) significantly decreased with increasing sintering temperature. In addition to the decrease of the microporosity, the crystal size increased with increasing sintering temperature. These two effects resulted in a significant decrease of the specific surface area of the ceramics with increasing sintering temperatures. Samples of HA1150, HA1250, BCP1100, BCP1150 and BCP1200 were implanted in the back muscles of Dutch milk goats and harvested at 6 and 12 weeks post implantation. After explantation, histomorphometrical analysis was performed on all implants. All implanted materials except HA1250 induced bone. However, large variations in the amounts of induced bone were observed between different materials and between individual animals. Histomorphometrical results showed that the presence of micropores within macropore walls is necessary to make a material osteoinductive. We postulate that introduction of microporosity within macropores, and consequent increase of the specific surface area, affects the interface dynamics of the ceramic in such a way that relevant cells are triggered to differentiate into the osteogenic lineage.

Species and muscle differences in L-carnitine levels in skeletal muscles based on a new simple assay

We have adapted the enzymatic method [Biochemical and Biophysical Research Communications 176 (3) (1991) 1617] for the safe and rapid assay of L-carnitine (L-CA) in skeletal muscle using a microplate reader. The concentration of L-CA in fresh semitendinosus muscle from broiler chicken, pig, beef cattle, deer, horse and goat muscle were 0.69, 1.09, 1.86–3.57, 4.57, 4.95 and 11.36 μmol/g wet weight, respectively. The animals which had higher concentration of L-CA, also had the highest amounts of myoglobin as an index to the redness of the muscle. Furthermore, we investigated this relationship between white muscle, M. pectoralis profundus, and red muscle, M. soleus, in laying hens. The L-CA and myoglobin concentration in red muscle were significantly higher than those in white muscle ( p<0.01). These findings suggest that L-CA concentration in muscle is related to oxygen metabolism and to myofiber types.

Biological performance of uncoated and octacalcium phosphate-coated Ti6Al4V

The in vivo behavior of a porous Ti6Al4V material that was produced by a positive replica technique, with and without an octacalcium phosphate (OCP) coating, has been studied both in the back muscle and femur of goats. Macro- and microporous biphasic calcium phosphate (BCP) ceramic, known to be both osteoconductive and able to induce ectopic bone formation, was used for comparison purpose. The three groups of materials (Ti6Al4V, OCP Ti6Al4V and BCP) were implanted transcortically and intramuscularly for 6 and 12 weeks in 10 adult Dutch milk goats in order to study their osteointegration and osteoinductive potential. In femoral defects, both OCP Ti6Al4V and BCP were performing better than the uncoated Ti6Al4V, at both time points. BCP showed a higher bone amount than OCP Ti6Al4V after 6 weeks of implantation, while after 12 weeks, this difference was no longer significant. Ectopic bone formation was found in both OCP Ti6Al4V and BCP implants after 6 and 12 weeks. The quantity of ectopically formed bone was limited as was the amount of animals in which the bone was observed. Ectopic bone formation was not found in uncoated titanium alloy implants, suggesting that the presence of calcium phosphate (CaP) is important for bone induction. This study showed that CaPs in the form of coating on metal implants or in the form of bulk ceramic have a significantly positive effect on the bone healing process.

Osteogenecity of octacalcium phosphate coatings applied on porous metal implants.

The biomimetic route allows the homogeneous deposition of calcium phosphate (Ca-P) coatings on porous implants by immersion in simulated physiologic solution. In addition, various Ca-P phases, such as octacalcium phosphate (OCP) or bone-like carbonated apatite (BCA), which are stable only at low temperatures, can be deposited. In this pilot study, experiments were designed with a twofold-purpose: (1) to investigate the osteoinduction of OCP-coated and noncoated porous tantalum cylinders and of dense titanium alloy cylinders (5 mm in diameter and 10 mm in length) in the back muscle of goats at 12 and 24 weeks (n = 4); and (2) to compare the osteogenic potentials of BCA-coated, OCP-coated, and bare porous tantalum cylinders in a gap of 1 mm created in the femoral condyle of a goat at 12 weeks (n = 2). In the goat muscle, after 12 weeks the OCP-coated porous cylinder had induced ectopic bone as well as bone within the cavity of the OCP-coated dense titanium cylinder. In the femoral condyle, bone did not fill the gap in any of the porous implants. In contrast with the two other groups, OCP-coated porous cylinders exhibited bone formation in the center of the implant. The nature of the Ca-P coating, via its microstructure, its dissolution rate, and its specific interactions with body fluids, may influence the osteogenecity of the Ca-P biomaterial.

DNA injection in combination with electroporation: a novel method for vaccination of farmed ruminants.

Injection of plasmid DNA encoding antigens into rodents followed by electroporation improved the immune response when compared with injection without electroporation (Widera et al. J Immunol 2000;164:4635-40; Zucchelli et al. J Virol 2000;74:11598-607; Kadowaki et al. Vaccine 2000;18:2779-88). The present study describes the extension of this technology to farm animals, by injecting plasmid DNA encoding mycobacterial antigens (MPB70, Ag85B and Hsp65) into the muscles of goats and cattle using two different types of electrodes, both allowing DNA delivery at the site of electroporation. The animals were vaccinated under local anaesthesia without any observed immediate or long-term distress or discomfort, or any behavioural signs of muscle damage or pathological changes after the electroporation. DNA-injected and electroporated goats showed increased humoral response after the primary vaccination when compared with nonelectroporated animals. Improved T-cell responses following electroporation were observed in hsp65 DNA-vaccinated cattle. DNA injection with or without electroporation did not compromise the specificity of the tuberculin skin test. In conclusion, a protocol applying in vivo electroporation free of side effects to farmed ruminants was established. In addition, we show that DNA vaccination in combination with electroporation can improve the primary immune responses to the encoded antigens.

Castration and slaughter age effects on fat components of “Mestiço” goat meat

The effect of castration and slaughter age on fat, cholesterol, phospholipids and fatty acid contents was determined for muscles of native Brazilian goat meat. Groups of castrated and intact “Mestiço” goats were slaughtered at 175, 220, 265 and 310 days of age. Castration and slaughter age had a significant effect on total cholesterol and fatty acids contents. The cholesterol content increased with advance in slaughter age. Meat from castrated goat had a higher cholesterol content than that from intacts. Goat muscle contained mostly C18:1 (38–44%), C18:0 (23–25%), C16:0 (18–21%), and C18:2 (4–6%) fatty acids. There were no differences in levels of saturated, unsaturated and polyunsaturated fatty acids among the four groups slaughtered at different intervals. Castrated goat meat contained significantly greater unsaturated and polyunsaturated fatty acids than that of intacts. Total fat and total phospholipids percentages ranged from 3.0 to 3.4 g/100 g and 10.6 to 11.1 mg/100 g, respectively for intact and castrated goats.

Fatty acid composition of goat muscles and fat depots: a review

In addition to the fat content of muscle and adipose depots, the fatty acid composition of lipids affects meat quality. Furthermore, relevant reports are difficult to use for comparisons, in that samples were collected from muscles and fat depots at various anatomical locations and experiments entailed different objectives, designs, procedures and methodologies. Nonetheless, based on currently available publications, according to a recent classification of meats by concentrations of potentially cholesterol-raising, and neutral, and cholesterol-lowering effects, average values for goat muscles appear better than for beef and lamb. Feeding dry diets seems to increase levels of unsaturated fatty acids and stearic acid in fat depots compared with milk or milk replacer. Increasing concentrate consumption can increase levels of odd-numbered and branched chain fatty acids in subcutaneous fat depots. With increasing age of unweaned kids, the level of stearic acid in fat depots decreases, and with increasing live weight of weaned kids levels of saturated fatty acids increase, and contents of monounsaturated fatty acids decrease in most fat depots. This review of a currently limited database indicates need for further experimentation to characterize interactions among factors such as breed, age and nutritional conditions in the fatty acid composition of carcass lipids of goats so as to gain a fuller understanding of goat meat quality.

Neuromuscular function of the latissimus dorsi muscle in goats after dynamic cardiomyoplasty.

Skeletal muscle deterioration is emerging as a limitation to long-term cardiac assist by dynamic cardiomyoplasty. Chronic electrical stimulation of in situ skeletal muscle showed that ischemia, decreased muscle preload, muscle overuse, and chronic electrical stimulation are factors for muscle deterioration. Transposition around the heart has been associated with signs of muscle denervation after chronic electrical stimulation. To evaluate latissimus dorsi muscle neuromuscular function after longterm dynamic cardiomyoplasty, we performed neuromuscular functional analysis and histology on the latissimus dorsi muscle and thoracodorsal nerve of six normal goats and six goats after 6 months of dynamic cardiomyoplasty. Electromyographic analysis showed positive sharp waves and fibrillation potentials in the latissimus dorsi of three goats from the dynamic cardiomyoplasty group. Conduction velocity of the thoracodorsal nerve of goats from the dynamic cardiomyoplasty group (58.32+/-9.80 m/s) was reduced compared to the goats from the control group (71.48+/-5.71 m/s, P = 0.02). Histologic changes in skeletal muscle were compatible with denervation. Loss of myelin sheaths, collapse of endoneurial connective tissue, and solitary foci of axonophagia and myelinophagia further documented severe injury to the thoracodorsal nerve in goats from the dynamic cardiomyoplasty group. The latissimus dorsi muscle wrap was denervated after long-term dynamic cardiomyoplasty. Traction on the neurovascular pedicle at each contraction of the transposed muscle may induce afferent axonal injury of the thoracodorsal nerve resulting in diminished muscular function.

Respiratory-related pharyngeal constrictor muscle activity in awake goats

Respiratory-related electromyogram (EMG) activities of the middle (MPC) and inferior (IPC) pharyngeal constrictor (PC) muscles were determined simultaneously with up to six additional upper airway abductor and adductor muscles in awake adult goats. Phasic PC activation began in late inspiration and persisted throughout expiration with a steady, an augmenting or a biphasic pattern of activity. Considerable differences were noted in the EMG responses of the MPC and IPC muscles to respiratory-related stimuli. During hypoxia and hypercapnia, phasic MPC activity decreased or was not recruited whereas phasic IPC activity was augmented with increased chemical drive. During spontaneous augmented breaths and peripheral chemoreceptor stimulation with sodium cyanide, the pattern of activation of the MPC was similar to that of the thyroarytenoid muscle (TA), a laryngeal adductor whereas IPC activity was strikingly similar to activity of the laryngeal and pharyngeal dilators. The expiratory portion of an augmented breath was associated with increased phasic MPC and TA but not IPC activities. Dopamine-induced apneas resulted in tonic activation of the MPC and TA at a level equal to or greater than control activity but no recruitment of IPC activity. The marked differences in MPC and IPC responses to respiratory-related stimuli suggests that these muscles may have different mechanical effects on pharyngeal airway caliber in the goat. The results suggest that the MPC may help brake expiratory flow thus helping to control expiratory timing and lung volume. In contrast, the IPC may promote pharyngeal airway patency by stiffening or dilating the pharyngeal airway. The results demonstrate that a variety of stimuli can influence respiratory-related PC activity and suggest that the PC muscles are important in the regulation of breathing and upper airway patency.

Neuromuscular function of the latissimus dorsi muscle in goats after long-term dynamic cardiomyoplasty

Neuromuscular function of the latissimus dorsi muscle in goats after long-term dynamic cardiomyoplasty

Neuromuscular Function of the Latissimus Dorsi Muscle in Goats After Long-term Dynamic Cardiomyoplasty

Neuromuscular Function of the Latissimus Dorsi Muscle in Goats After Long-term Dynamic Cardiomyoplasty

Molecular basis for decreased muscle chloride conductance in the myotonic goat.

Certain forms of myotonia, a condition characterized by delayed relaxation of muscle secondary to sarcolemmal hyperexcitability, are caused by diminished chloride conductance in the muscle cell membrane. We have investigated the molecular basis for decreased muscle chloride conductance in the myotonic goat, an historically important animal model for the elucidation of the role of chloride in muscle excitation. A single nucleotide change causing the substitution of proline for a conserved alanine residue in the carboxyl terminus of the goat muscle chloride channel (gCIC-1) was discovered. Heterologous expression of the mutation demonstrated a substantial (+47 mV) shift in the midpoint of steady-state activation of the channel, resulting in a diminished channel open probability at voltages near the resting membrane potential of skeletal muscle. These results provide a molecular basis for the decreased chloride conductance in myotonic muscle.

Insulin-sensitive glucose transporter transcript levels in calf muscles assessed with a bovine GLUT4 cDNA fragment

Previous studies have shown that the expression of the insulin-sensitive glucose transporter (GLUT4) is lower in oxidative muscles than in glycolytic muscles in bovines and goats in contrast to observations in rats. Additional experiments in this work provide very strong arguments that the immunoreactive band detected does represent GLUT4 protein, which further validates our previous results. Therefore, to determine the level of regulation, the main objective of the present study was to measure GLUT4 mRNA amounts in various bovine muscles. A 241-bp fragment of the bovine GLUT4 cDNA was cloned by polymerase chain reaction (PCR). It shares 80–90% sequence identity with related sequences in other species. This PCR-amplified bovine GLUT4 probe was used to determine the distribution of GLUT4 mRNA in bovine tissues in comparison with that of GLUT1 mRNA. Moreover, GLUT4 mRNA amounts were quantified by Northernblot analysis in heart and seven skeletal muscles with various oxidative and glycolytic activities from seven ruminant calves. GLUT4 mRNA was detected by Northern-blot analysis only in calf insulin-sensitive tissues. In contrast, GLUT1 mRNA was detected in all tissues studied except liver. GLUT4 mRNA amount was the highest in masseter and heart, which are oxidative muscles (1.67 ± 0.16 and 1.53 ± 0.19 units/g wet tissue weight, respectively) and the lowest in glycolytic or oxido-glycolytic muscles (0.31 ± 0.04 to 1.00 ± 0.09 units/g wet tissue weight; SEM, n = 7). These data and our previous results provide evidence for translational and/or posttranslational control mechanisms of bovine GLUT4 protein expression in a muscle type-specific manner.

Differential effect of ventrolateral medullary cooling on respiratory muscles of goats.

The objective was to determine whether there is an inhomogeneous response of respiratory muscles during cooling-induced ventrolateral medullary (VLM) neuronal dysfunction in anesthetized and awake goats. Thermodes for cooling were chronically implanted on all or portions of rostral, intermediate, and caudal areas of the VLM of 16 adult goats. Electromyograms (EMGs) were obtained from chronically implanted wires in the diaphragm (di), transversus abdominis (TA), and triangularis sterni (TS) muscles. During some periods of cooling in 9 of 16 anesthetized airway-intubated goats, complete cessation of EMGdi coincided with a reduced yet sustained inspiratory flow. In six awake tracheotomized goats, VLM cooling decreased (P < 0.05) EMGdi duration and minute activity more than inspiratory duration and minute ventilation. Cooling thus decreased activation of the diaphragm more than activation of other respiratory muscles. On the other hand, during VLM cooling in 3 of 10 airway-intact awake goats, cessation of inspiratory flow coincided with sustained EMGdi, suggesting that cooling decreased stimulation of the upper airway muscles more than stimulation of the diaphragm. Finally, VLM cooling in a majority of goats decreased EMGTA and EMGTS more than EMGdi. We conclude that VLM neuronal dysfunction has a differential effect on respiratory muscles of adult anesthetized and awake goats.

Morphologic and morphometric characteristics of limb muscles of the goat

Use of (1) two histochemical reactions (myosin adenosine triphosphatase, mATPase, and nicotinamide adenine dinucleotide dehydrogenase-tetrazolium reductase, NADH-TR), (2) biopsies from deep and superficial parts of muscles, and (3) different indices (percentage population, PP, vs. cross-sectional area proportion, CSAP; and lesser (LD) vs. equivalent diameter (D)) for estimating fibre type composition or size were compared, and data obtained on composition and size of fibre types in 25 limb muscles of goats. Both reactions differentiated types I, IIA and IIB fibres and yielded reproducible but different estimates of fibre composition or size. In the extensor carpi radialis muscle, mATPase sections yielded higher estimates of type I fibre composition (7.2 ± 0.1 vs. 6.5 ± 0.1; P < 0.01) and lower estimates of type IIA fibre diameter (45.3 ± 1.5 vs. 48.4 ± 1.0; P < 0.05) than NADH-TR sections. PP and CSAP yielded different estimates of composition of types I, IIA and IIB fibres (7.2 ± 0.1 vs. 6.6 ± 0.3, 30.2 ± 1.6 vs. 28.4 ± 1.2 and 62.3 ± 1.8 vs. 65.0 ± 1.4, respectively; P < 0.05) as did biopsies from superficial and deep parts of the muscle (6.4 ± 0.2 vs. 35.8 ± 0.3, 26.3 ± 5.9 vs. 54.3 ± 4.2, and 67.4 ± 5.7 vs. 9.9 ±4 .5, respectively, for types I, IIA and IIB fibres; P < 0.001). LD and D also yielded different estimates of fibre diameter. Most limb muscles of goats contained types I, IIA, IIB and few IIC fibres in varying compositions and sizes. Type I fibre composition ranged from 6.4% in the tensor fascia lata to over 99.7% in the soleus muscles, increased with depth into extensor muscles and decreased with depth into flexor muscles, the latter being contrary to the pattern of fibre type stratification in other species. Goat muscles also differed in that mATPase and NADH-TR activities did not exhibit a reciprocal relationship in types IIA and IIB fibres as in many other mammalian species. These differences indicate caution in comparing results between studies that use different methods, and call for specification or standardization of biopsy sites and methods used to study muscle biopsies. They also suggest that goats may differ from other species in the contractile properties of types IIA and IIB muscle fibres.

&lt;sup&gt;31&lt;/sup&gt;P NMR法によるヤギ骨格筋の死後変化の非破壊計測

生体総織のエネルギ-代謝状態に関する情報を破壊的かつ経時的に得ることが可能な31P核磁気共鳴法(NMP法)により,生理学的•生化学的特性を異にする2種類のヤギ骨格筋(棘上筋および大腿筋膜張筋)の屠殺後の高エネルギーリン酸化合物の消長を経時的に調べた.また,ウサギ,ブタなどの限られた動物の一部の骨格筋に存在することが報告されているglycerophosphorylcholine (GPC)がヤギの筋肉で見出せるかどうかを検討した.雌性ザーネン種成ヤギ(6頭)をペントバルビタール麻酔下に放血屠殺し,直ちに筋肉を採取した.筋肉を整形後,直径10mmのNMR試料管に挿入し,屠殺後1,2,3,4,5,6,正2および24時間の各時点で31P NMR測定を行ない,クレアチンリン酸,ATPの経時減少および細胞内pHの変化を調べた.測定はすべて25±1°Cで行なった.併せて,両筋の組織化学的特性の差異を明らかにするため,凍結横断切片を作成し,免疫および酵素組織化学的方法により筋線維型組成を明らかにした.主にI型筋線維(slow-twitch)から構成される棘上筋とII型筋線維(fast-twitch)優勢の大腿筋膜張筋では,屠殺後の高エネルギーリン酸化合物の経時減少に顕著な差が認められた.すなわち,棘上筋では大腿筋膜張筋と比べてクレアチンリン酸およびATPの減少•消失が早かった.限られた家畜のI型筋線維主体の筋で存在が報告されているGPCがヤギ棘上筋にも存在することが31P NMR測定により明らかとなった.大腿筋張筋ではこの物質は認められなかった.細胞内PHの低下パターンにも2種類の筋肉間で差が認められた.すなわち,屠殺直後と屠殺24時間後の時点では両者間に差がないものの,棘上筋の細胞内pH低下が早く,屠殺後2～6時間の各時点で細胞内pHに有意な差が認あられた.

Type, diameter and distribution of fibres in some respiratory and abdominal muscles of the goat.

This study was designed to determine the histochemical properties, size and composition of fibres in the diaphragm, intercostal and abdominal muscles of goats to clarify whether reported similarities in respiratory muscle physiology between goats and humans have a structural basis. Serial sections (10 microns) of muscular tissue from adult female goats were stained for myosin adenosine triphosphatase and reduced nicotinamide adenine dinucleotide dehydrogenase-tetrazolium reductase activities; the fibres were classified into type I, IIA and IIB; and their mean diameter and composition were determined. Abdominal and intercostal muscles contained types I, IIA and IIB fibres in the ratio 1:1:1, and the mean diameter of the fibres ranged from 49.2 to 62.2 microns. In contrast, the diaphragm contained 58.9% type I and 41.1% type II fibres, and the latter could not be differentiated into types IIA and IIB. Diaphragmatic fibres were also smaller (36.9-40.9 microns). These findings contrast with those in humans, where the diaphragm, intercostal and abdominal muscles contain > 50% type I fibres and have fibres of identical diameter. The differences in fibre characteristics between the diaphragm, intercostal and abdominal muscles of goats and the differences between goats and humans need to be taken into consideration in interpreting the results from studies in respiratory muscle physiology.

Fatty Acid Composition of Goat Organ and Muscle Meat of Alpine and Nubian Breeds

ABSTRACTFatty acid compositions of liver, heart, kidney, Longissimus dorsi (LD) and Biceps femoris (BF) of two goat breeds were evaluated using capillary gas chromatography (GC). Lauric (C12:0) acid was absent from the liver and kidney. All organ samples had significantly (P &lt; 0.01) greater polyunsaturated fatty acids (PUFA) than the LD and BF muscles. The organs also contained significantly (P &lt; 0.01) higher saturated fatty acids (SFA) than the skeletal muscles, whereas the opposite trend occurred for the C18:1 contents. Levels of 14:0, 16:0, and 18:2 acids were related to breed, while those of 14:0, 18:0, 18:1, 18:2, and 20:4 acids were related to tissues. Goat muscle had higher PUFA:SFA ratio than those reported for beef, which may be important in human nutrition.

Evaluation of a new conditioning protocol of the latissimus dorsi muscle in goats

Evaluation of a new conditioning protocol of the latissimus dorsi muscle in goats