Muscle Tissue Of Rabbits Research Articles

ПРОИЗВОДСТВО МЯСОРАСТИТЕЛЬНЫХ ПОЛУФАБРИКАТОВ, ОБОГАЩЕННЫХ ШЕЛУХОЙ СЕМЯН ПОДОРОЖНИКА

The article shows the results of research on the development of the formulation and technology of stuffed rabbit meat enriched with psyllium powder. In the control recipe of the meat-growing semi-finished product, pork in minced meat was replaced with rabbit meat and part of rice with 1% psyllium powder. The vitamin and mineral composition of rabbit meat is significantly superior to other types of meat. Rabbit meat is rich in vitamins B6, B12, PP, contains a lot of iron, phosphorus, cobalt, manganese, fluorine and potassium. Rabbit muscle tissue has a low content of sodium salts, which makes rabbit meat a low-calorie product. Rabbit meat gives the product dietary properties, and when the product is enriched with psyllium powder, its beneficial properties increase doubly. Psyllium contains a large amount of organic fiber, it is an enterosorbent, a prebiotic with adsorbing properties. Psyllium also has a positive effect on the microflora of the gastrointesti-nal tract, increasing the number of beneficial bacteria Lachnospira, Roseburia and Faecalibacterium, pro-ducers of essential intestinal butyric acid. Eating foods containing psyllium husks lowers cholesterol and im-proves blood pressure, as psyllium absorbs fats and removes them from the body. We believe that a meat product enriched with psyllium powder is relevant for the diet of people suffering from "bad" cholesterol, obesity, problems with the gastrointestinal tract, as well as for the diet of people with diabetes and athletes.

Effects of fermented rapeseed meal on gastrointestinal morphometry and meat quality of rabbits (Oryctolagus cuniculus)

The aim of the study was to determine effects of three levels of rapeseed meal (4% - FR4, 8% - FR8, and 12% - FR12) which has undergone fermentation and drying processes (FRSM) in the diet of crossbred rabbits (New Zealand White × Popielno White, n=40) on their gastrointestinal tract morphometry, internal organs weight, and proximate composition and physicochemical properties of skeletal muscles (biceps femoris – BF, and joined longissimus thoracis and longissimus lumborum – LTL). Although the total length of the digestive tract of rabbits did not differ significantly, the addition of FRSM was found to significantly (P < 0.01) affect the lengthening of caecum (between 0.73 and 0.91 m) and large intestine (from 1.07 to 1.24 m) in comparison to the control group (0.31 m and 0.54 m, respectively). Additionally, the diet with FRSM significantly (P < 0.05) influenced the weight of the heart, whereby the lightest hearts was found in the control group (10.0 g) and the heaviest in group FR8 (14.03 g).The content of proximate chemical constituents in rabbit muscle tissues was similar, with except of collagen percentage. A larger share of FRSM (from 4% to 12%) was accompanied by an increased level of collagen in LTL (P < 0.01), from 0.33% in group C to 0.46% in group FR12. In BF muscle the significantly (P < 0.01) highest collagen content was found in FR4 (2.27%) and the lowest in FR12 (0.88%). The significant decrease in the ultimate pH of LTL (from 5.71 to 5.62) and water-holding capacity (from 44.5 to 49.2 mg) as the share of FRSM in the diet increased were observed in comparison with the group C (5.74 and 37.9 mg, respectively). These effects were not noted in the BF muscle of the rabbits. A diet with FRSM significantly affected all colour parameters (CIE L*, a*, b*, C*, and h°) of the LTL and the yellowness (b*) and saturation (C*) of the BF muscle. The lightness (L*) of LTL muscles was significantly (P < 0.05) higher in the experimental rabbits, irrespective of the level of FRSM (51.50 ≤ L* ≤ 52.61), than in the control group (L*=47.51). The increased content of collagen (between 4.9 and 5.4 mg/g) and shear force (between 25.4 and 37.7 N) for cooked LTL compared to control group (4.0 mg/g and 21. N, respectively) were observed. It can be concluded that FRSM is the alternative dietary component for rabbits with no negative effect on meat full potential for further processing and case-ready purposes.

Meat receiving with functional properties when feeding the rabbits and broiler chickens of metal and protein complexes

The results of researches on the infl uence of new metal and protein compounds in the feeding of rabbits and broiler chickens on the quality of meat have been presented in the paper. The researches have been aimed at solving the urgent problem of providing the population of country with complete-fl edged diets, which today account for up to 30 % of meat products. The paper shows that a lifetime change in the chemical composition and nutritional value of muscle tissue, obtaining functional foods is possible when correcting the micromineral part of the diet of animals through the use of metal and protein complexes Belmin and Chrombelmin. The use of modern research methods allowed us to determine the optimal rate of feeding these feed additives. The results have been shown that the inclusion in the diet of rabbits organic complex Belmin in an amount of 2,0 dose per head/day has increased content in muscle tissue of rabbits of iron (+37,8 %, P &lt; 0,001), copper (+34,66 %, P &lt; 0,001), zinc (+27,01 %, P &lt; 0,001) and essential amino acids (+5,1–0,53 %). Feeding Chrombelmin to broiler chickens as part of compound feed (0,15 %) has increased the level of selenium in the chest muscle by 3 times (P &lt; 0,001), in the femoral muscle – by 1,25 times. The content of manganese, zinc, and chromium changes slightly. In the breast muscle of broilers the lipid content has been increased by 1,37 % (P &lt; 0,05), and in the femoral muscle it decreased by 1,11 % (P &lt; 0,05). The use of metal and protein feed additives Belmin and Chrombelmin in animal husbandry increases productivity, as well as the production of meat products with the increase of content of micronutrients, which will provide the population with not only high-quality, but also useful for health food products.

Особенности накопления йода в мышцах кроликов на фоне использования антиоксидантов в липосомальной форме

Abstract. The problem of iodine saturation of livestock products for residents of most regions of our country requires a detailed study. One of the factors is the obtaining of livestock products enriched with organic iodine. The study of the degree of accumulation of iodine in the muscle tissue of rabbits at the background of the use of liposomal form of antioxidants enriched with organic iodine (LFA) was the main purpose of the research. Methods. An experiment on rabbits of the California breed were used. The first control group received the main diet (MD) in the form of a granular mixture. The experimental second group was given LFA based on White sea laminarias at the rate of 250 g per ton of feed mixture of MD. The third experimental group was injected with MD the LFA with Black sea Cystoseira. The formation of meat indicators, chemical analysis of muscle tissue, the level of accumulation of trace elements, including iodine in muscle tissue was studied indicators. Results. Based on the somatometric method of evaluating rabbits, it was found that the young animals of the experimental groups form a more eirisomus-type body (from 60 to 70 % of the total population). All indicators of the interactions of somatic parameters in the young groups II and III positive and highly significant correlation, and the correlation index of the density of the body correlated positively with body length (r = +0,67, p ≤ 0.01), chest girth (r = +0,86, p ≤ 0.001), length of loin (r = +0,61, p ≤ 0,01), the length of the backside (r = +0.71, p ≤ 0.001) and head measurement (r = +0,57, p ≤ 0.05). An improvement of the indicators of slaughter of experimental groups of young animals was stated. The slaughter weight increases by 12.2 %, and the mass of internal organs responsible for digestion by 4.5–43.8 %. A percentage of increase in muscle tissue during boning by 10.0–15.9 % and a decrease in the proportion of low-value parts in the carcass-bone tissue by 8.6–9.9 % was stated. Iodine in the average sample of muscle tissue of the experimental groups increases by 91.8 mcg (p ≤ 0.05) in animals of the second group and by 113.3 mcg (p ≤ 0.05) of the third group.

Evaluation of rabbit meat properties as raw material for functional products manufacturing

The research results of the mass yield and composition of the anatomical areas of rabbits carcass, the mechanisms of autolysis of rabbit meat and histomorphological changes during the course of autolysis were presented in the work. The degree of protein digestibility of rabbit muscle tissue was determined. The object of research was the California rabbit carcass. It was established that the process of meat maturing would be completed in 8 hours. Matured meat is characterized by higher nutritional value and quality. The developing in the rabbit carcass processes affect the functional and technological properties of meat during the rigor mortis resolution and at the beginning of the maturing stage. Functional and technological properties are: 53.7% - water-binding capacity and 50.6% - water-holding capacity. 24 hours later after slaughter, the functional and technological properties as a whole increased to 64.1 and 61.7, respectively, which corresponds to 85% of fresh-killed meat. Such indicators of functional and technological properties are due to the high content of high-quality complete proteins. The high digestibility of the protein components of rabbits muscle tissue was observed. The autolysis stages were illustrated by the microstructural and qualitative characteristics of rabbit meat. The deep character of autolytic processes in the longest back muscle 12 hours after rabbit slaughter, which resulted in the formation of physico-chemical, biochemical, organoleptic properties of meat, ensuring products high quality was identified. Less intensive processes took place in the muscle tissue of piriformis muscle, as well as the pre-blade muscle, which was explained by the structure peculiarities of these parts of the muscular system. The research results indicate the prospects of rabbit meat using in functional products manufacturing. The technologies developed allow to take into account preferences and income level of consumers.

Application of the Mechanical High-Pressure Method Combined with High-Performance Liquid Chromatography–Tandem Mass Spectrometry for Determination of Veterinary Drug Residues in Incurred Chicken and Rabbit Muscle Tissues

Rapid sample preparation is a key step in the field of food safety. A mechanical high-pressure method using a laboratory-made meat press machine was first introduced in this study to process the incurred muscle samples of chicken and rabbit. By applying high pressure to animal muscle, the meat juice was obtained. After extraction and purification, veterinary drug residues in the juice were qualitatively and quantitatively analyzed by using high-performance liquid chromatography-tandem mass spectrometry. The sample press conditions and extraction solvents were optimized. Under the optimal conditions, all veterinary drug residues, including tetracycline, enrofloxacin, clenbuterol, ampicillin, lincomycin, erythromycin, and sulfadiazine, in the incurred samples were detected. The residual concentration of drugs in samples obtained by using the mechanical high-pressure method can reach up to 94.0% of that obtained by using the common homogenization method, suggesting that drug residues exist in the tissue juice, which justifies the use of the mechanical high-pressure method. Moreover, with the mechanical high-pressure method, the sample preparation time was shortened by five times, and the consumption of the extraction solvent was reduced by 50%, relative to the homogenization method.

Preparation and evaluation of tilmicosin microspheres and lung-targeting studies in rabbits

Tilmicosin (TMS) is a macrolide used extensively for pulmonary infections in clinical veterinary medicine. However, TMS has frequent administration and short elimination half-life. Therefore, tilmicosin–gelatine microspheres (TMS–GMS) were prepared by an emulsion-chemical cross-linking technique as a sustained-release formulation to extend drug half-life. The particle size distribution, in-vitro sustained-release properties, stability, and physical characteristics, as well as pharmacokinetic (PK) characteristics, were evaluated in rabbits.TMS–GMS were spherical in shape and had a mean diameter of 11.34±1.20μm; 95.65% of the microspheres varied in size from 5.0 to 25.0μm. Light and thermal stability tests indicated no significant changes in all observed indices. Importantly, compared to crude TMS, slower release of TMS from TMS–GMS was noted in drug release studies (in vitro). Pharmacokinetic (PK) characteristics were examined in the lung, liver, heart, kidney and muscle tissue of rabbits following IM injection of TMS–GMS or TMS-injection at a dose of 10mg/kg. The elimination half-life of TMS–GMS (59.21±0.21h) was longer than that of TMS-injection (38.56±0.13h) in the lung. The ratio of peak concentration (Ce) of TMS–GMS to TMS-injection was 2.19 (>1) in the lung, demonstrating the selectivity of TMS–GMS to target the lung compared to that of other tissues (Ce<1). Interestingly, the uptake value of TMS from TMS–GMS was 8.48 times higher in the lung than that for the TMS-injection, and was slightly higher than in the liver (1.85), heart (1.72), kidney (2.44) and muscle (2.79) tissues. TMS–GMS is a sustained-release formulation of TMS with potential to be used in veterinary clinical applications; possible benefits include lung-targeting and prolonged elimination half-life.

Invitro and invivo analysis of the biocompatibility of two novel and injectable calcium phosphate cements.

Calcium phosphate cements (CPCs) have been widely used as bone graft substitutes for many years. The aim of this study was to evaluate the biocompatibility of two novel injectable, bioactive cements: β-tricalcium phosphate (β-TCP)/CPC and chitosan microsphere/CPC in vitro and in vivo. This was accomplished by culturing mouse pre-osteoblastic cells (MC3T3-E1) on discs and pastes of CPCs. Cell growth, adhesion, proliferation and differentiation were assessed by 3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide and alkaline phosphatase assays as well as by scanning electron microscopy and fluorescence. The effect of CPC paste curing was also evaluated. Implantation of two materials into the muscle tissue of rabbits was also studied and evaluated by histological analysis. Cell analysis indicated good biocompatibility in vitro. The fluorescence assay suggested that the cured material discs had no obvious effect on cell growth, while the curing process did. Histological examination showed no inflammatory cell infiltration into soft tissue. These data suggest that β-TCP/CPC and chitosan microsphere/CPC composites may be promising injectable material for bone tissue engineering.

The use of algae in animal nutrition

In this review article the use of algae as feed in animal nutrition is being examined. The algae evolved on earth 3.5 billion years ago. They are primitive, generally aquatic and photosynthetic organisms, which range in size from 0,2-2,0 μιτι in diameter -microalgae (phytoplankton) up to 60 m length- macroalgae and may divide once or more per day. Algae are classified using a combination of characteristics in the chlorophyta, phaeophyta, chrysophyta, rhodophyta (all of them are macroalgae), pyrrhophyta and cyanophyta (they are microalgae). The chemical composition of algae varies over a wide range and depends on environmental conditions. Algae are necessary in the reduction of greenhouse gas emissions. They can be used as biodisel from their bio-lipid oil, as feed additives (alginates, carrageenans, agar, pigments), as therapeutic agents, as cosmetics, as organic fertilizer. Moreover, edible algae are considered sources of minerals and a complementary source of food protein for human -especially infunctional foods and animal nutrition, both in ruminants and monogastric animals. Algae in the rations of lactating cows increased milk production, the average milk protein, the amount of lactose, and prolonged the lactation period, while algae rich in (n-3) fatty acids effected positively on this fatty acid content of milk. In calves the dietary algae en-hanced immune function and improved carcass characteristics. Regarding the ewes, the algae nutrition affected milk fat composition and their dairy products. Researches on monogastric animals showed that the dietary supplementation of algae rich in docosqexaenoic acid increased its content in muscle tissue of rabbits, heavy pigs (live weight around 160 kg) and in the egg yolk of laying hens. In addition, algae in poultry diets can be used effectively as pigment sources both in egg yolk and in broiler skin and shanks. Algae have been found also to be a valuable food for fish farmed by acquaculture. However, further investigation is needed concerning the use of algae in human and animal nutrition.

In Vivo Study on Degradation Behavior and Histologic Response of Pure Magnesium in Muscles

When an orthopedics device is implanted into bone injury site, it will contact the soft tissue (skeletal muscle, fascia, ligament etc.) except for bone. Magnesium based biodegradable metals are becoming an important research object in orthopedics due to their bioactivity to promote bone healing. In this study, pure Mg rods with and without chemical conversion coating were implanted into the muscle tissue of rabbits. Implants and their surrounding tissues were taken out for weight loss measurement, cross-sectional scanning electron microscopy observation, elemental distribution analysis and histological examination. The results showed that the chemical conversion coating would increase the in vivo corrosion resistance of pure Mg and decrease the accumulation of calcium (Ca) and phosphorus (P) elements around the implants. For the bare magnesium implant, both Ca and P contents in the surrounding tissues increased at the initial stage of implantation and then decreased at 12 weeks implantation, while for the magnesium with chemical conversion coating, Ca and P contents in the surrounding tissues decreased with the implantation time, but were not significant. The histological results demonstrated that there was no calcification in the muscle tissue with implantation of magnesium for up to 12 weeks. The chemical conversion coating not only increased the in vivo corrosion resistance of pure Mg, but also avoided the depositions of Ca and P in the surrounding tissues, meaning that pure magnesium should be bio-safe when contacting with muscle tissues.

Effects of expression of calpain mRNA in rabbits exposed to vibration by hind legs

To study the effects of expression of calpain mRNA in rabbits exposed to vibration by hind legs. 32 New Zealand rabbits were randomly divided into a control group and 3 experimental groups according to 4-hour energy-equivalent frequency-weighted acceleration[ahw (4)]: low (4.33 m/s(2)) , moderate (8.67 m/s(2)) and high (17.34 m/s(2)) intensity group to accepted the vibration by hind legs. 45 ds later, brain and skeletal muscle tissue of rabbits were taken to detect the expression of calpain-1 and calpain-2 mRNA by RT-qPCR technique. The relative content of calpain-1 mRNA in the brain tissues in rabbits of low, medium and high intensity group were 8.35±3.75,9.64±4.54,5.10±5.26. While the relative content of calpain-2 mRNA in the brain tissues in rabbits of low, medium and high intensity group were 7.34±4.97,8.50±5.66, 8.16±5.59. Compared with the control group (1.10±0.29, 0.56±0.43) , the expression of calpain-1 and calpain-2 mRNA of the intensity groups showed an significantly increasing trend (P<0.01). In skeletal muscle tissue, the relative content of calpain-1 mRNA were 4.36±2.05, 7.37±4.06, 12.46±6.21.Compared with the control group (0.98±0.59) , the expression of calpain-1 mRNA of experiment groups were significantly higher (P<0.05) .The expression of calpain-2 mRNA of the intensity groups had no significantly difference with the control group (P>0.05). The expression of calpain-1 and calpain-2 mRNA can be promoted by the vibration by the hind legs.

Preparation of Preproinsulin Gene Construct Containing the Metallothionein2A (pBINDMTChIns) and Its Expression in NIH3T3 Cell Line and Muscle Tissue of Alloxan Diabetic Rabbits

Background: Diabetes mellitus type 1, formerly called insulin-dependent diabetes, is one of the autoimmune diseases where insulinproducing cells are destroyed by autoimmune response via T cells. The new approaches in treatment of diabetes are using the stem cells, cell transplantation of islet β cell, gene transfer by virus based plasmids, and non-viral gene constructs. Objectives: The purpose of this study was to construct glucose inducible insulin gene plasmid and use it in the muscle tissue of the rabbit. Materials and Methods: To achieve this goal, the preproinsulin, metallothionein2A promoter and the response element to carbohydrate genes were cloned into pBIND plasmid by standard cloning methods, to construct pBINDMTChIns. The gene cloning products were confirmed by the polymerase chain reaction (PCR) and restriction enzyme digestion template. The recombinant plasmid, containing the preproinsulin gene, was transferred into NIH3T3 cells and insulin gene expression was evaluated by reverse transcriptase PCR and western blotting techniques. Plasmid naked DNA containing the preproinsulin gene was injected into the rabbits’ thigh muscles, and its expression was confirmed by western blotting method. Results: This study shows the prepared gene construct is inducible by glucose. Gene expression of preproinsulin was observed in muscle tissue of rabbits. Conclusions: These finding indicated that research in diabetes mellitus gene therapy could be performed on larger animals.

Totipotent stem cells could do everything ... or else nothing: the case of vascular reendothelialization

This editorial refers to ‘Circulating endothelial progenitor cells do not contribute to regeneration of endothelium after murine arterial injury’ by M.K. Hagensen et al. , pp. 223–231, this issue. And the rib, which the Lord God had taken from man, made he a woman, and brought her unto the man. (Gen. 2:22) In 1868, Goujon1 was awarded a prize of 500 francs by l'Academie de France in Paris for his presentation of very well-performed experiments ‘Sur les Proprietes Physiologiques de la Moelle des Os’ (on the Physiological Properties of Bone Marrow) in which he demonstrated the formation of bone tissue from autologous grafts of red bone marrow within skeletal muscle tissue of rabbits, chickens, and pigeons. These seminal experiments probably initiated the search for stem cells, responding to a long-lasting longing for reconstruction of damaged tissues by undifferentiated cells. It was not, however, until 1968 that this possibility was firmly reassessed2 and the recent story of stem cell research and deployment was initiated, although the term ‘mesenchymal stem cells’ was first coined by Caplan3 in 1991. This item is fully connected with the problem of repair of vascular injury, mainly caused by therapeutic interventions aimed at removing endoluminal (atherosclerotic) obstacles by angioplasty that by definition …

On the In Vivo Degradation Performance of Stranded 125I Seeds Connected With AZ31B Magnesium Alloy

Purpose: To observe degradation performance of stranded iodine-125 seeds connected with biodegradable AZ31B magnesium alloy in vivo; to compare degradation rate of biodegradable AZ31B magnesium alloy in rabbit VX2 tumor tissue and rabbit muscle tissue; when the tumor reduced by irradiation after the implantation of stranded seeds, to observe whether stranded seeds could break, whether seeds could gather with the dwindling of the tumor.

P82. Evaluation of rhBMP2 Fibrin Glue-associated Edema in Rabbit Muscle Tissue

P82. Evaluation of rhBMP2 Fibrin Glue-associated Edema in Rabbit Muscle Tissue

Dynamic high-resolution 1H and 31P NMR spectroscopy and 1H T2 measurements in postmortem rabbit muscles using slow magic angle spinning.

Postmortem changes in rabbit muscle tissue with different glycogen status (normal vs low) were followed continuously from 13 min postmortem until 8 h postmortem and again 20 h postmortem using simultaneous magic angle spinning (1)H and (31)P NMR spectroscopy together with measurement of the transverse relaxation time, T(2), of the muscle water. The (1)H metabolite spectra were measured using the phase-altered spinning sidebands (PASS) technique at a spinning rate of 40 Hz. pH values calculated from the (31)P NMR spectra using the chemical shifts of the C-6 line of histidine in the (1)H spectra and the chemical shifts of inorganic phosphate in the (31)P spectra confirmed the different muscle glycogen status in the tissues. High-resolution (1)H spectra obtained from the PASS technique revealed the presence of a new resonance line at approximately 6.8 ppm during the postmortem period, which were absent in muscles with low muscle glycogen content. This new resonance line may originate from the aminoprotons in creatine, and its appearance may be a result of a pH effect on the exchange rate between the amino and the water protons and thereby the NMR visibility. Alternatively, the new resonance line may originate from the aromatic protons in tyrosine, and its appearance may be a result of a pH-induced protein unfolding exposing hydrophobic amino acid residues to the aqueous environment. Further studies are needed to evaluate these hypotheses. Finally, distributed analysis of the water T(2) relaxation data revealed three relaxation populations and an increase in the population believed to reflect extramyofibrillar water through the postmortem period. This increase was significantly reduced (p < 0.0001) in samples from animals with low muscle glycogen content, indicating that the pH is controlling the extent of postmortem expulsion of water from myofibrillar structures. The significance of the postmortem increase in the amount extramyofibrillar water on the water-holding capacity was verified by centrifugation, which showed a reduced centrifugation loss in muscles with low preslaughter glycogen status (0.9 vs 1.9%, p = 0.07).

Vergleich nichtinvasiver MRT-Verfahren zur Temperaturmessung für den Einsatz bei medizinischen Thermotherapien

Novel methods for hyperthermia tumor therapy, such as high-intensity focused ultrasound (HIFU) or laser-induced thermotherapy (LITT), require accurate non-invasive temperature monitoring. Non-invasive temperature measurement using magnetic resonance imaging (MRI) is based on the analysis of changes in longitudinal relaxation time (T1), diffusion coefficient (D), or water proton resonance frequency (PRF). The purpose of this study was the development and comparative analysis of the three different approaches of MRI temperature monitoring (T1, D, and PRF). Measurements in phantoms (e.g., ultrasound gel) resulted in the following percent changes: T1-relaxation time: 1.98% /°C; diffusion coefficient: 2.22% /°C; and PRF: −0,0101 ppm /°C. All measurements were in good agreement with the literature. Temperature resolutions could also be measured from the inverse correlation of the data over the whole calibration range: T1: 2.1 ± 0.6 °C; D: 0.93 ± 0.2 °C; and PRF: 1.4 ± 0.3 °C. The diffusion and PRF methods were not applicable in fatty tissue. The use of the diffusion method was restricted due to prolonged echo time and anisotropic diffusion in tissue. Initial tests with rabbit muscle tissue in vivo indicated that MR thermometry via T1 and PRF procedures is feasible to monitor the local heating process induced by HIFU. The ultrasound applicators in the MR scanner did not substantially interfere with image quality.

Ectopic osteogenesis with biphasic ceramics of hydroxyapatite and tricalcium phosphate in rabbits

Porous calcium phosphate ceramics consisting of hydroxyapatite (HA) and tricalcium phosphate (TCP) with different HA to TCP ratio were implanted intramuscularly in rabbits for six months in order to carry out a comparative study on osteogenic activity of the ceramics. Bone formation was detected only in HT73 (HA to TCP ratio; 7–3) specimens. Other implants, HT28 (2–8) and HT010 (0–10), could not induce bone. After a six-month period of implantation, HT28 and HT010 implants showed obvious degradation of the implants changing their shape and size macro and microscopically. Microscopically, they showed aggregates of fine particles and appearance of multinucleated cells. However, HT73 implants was less degraded and could maintain their original structure macro and microscopically. This study showed that HT73 ceramics can induce bone in rabbit muscle tissue and it is considered that maintenance of porous structure, that is, degradation rate of the materials may be one of the affecting factors in ceramic-induced osteogenesis.

Isolating equine sarcoplasmic reticulum: its function during high intensity repeated sprints

SummaryA method has been developed for isolating equine sarcoplasmic reticulum (SR) and measuring calcium uptake by modifying methods previously established in rat and rabbit muscle tissue. Excisional biopsies were used to obtain muscle samples from the gluteal muscles of 10 Quarter Horses. Sarcoplasmic reticulum vesicles were isolated through homogenisation and differential centrifugation. Calcium uptake into the vesicles was monitored spectrophotometrically using a calcium probe, antipyrylazo III. An enzyme linked optical assay was employed to assess Mg++ ‐stimulated, Ca++ ‐stimulated and total ATPase activity in the isolated SR vesicles. The present results provide a system for obtaining SR microsomes and measuring calcium uptake in the isolated vesicles in a relatively short period of time. High intensity sprinting decreased calcium uptake and Ca‐ATPase activity of SR vesicles in horses.

Prediction of drug distribution in vivo on the basis of in vitro binding data.

For 11 drugs it was investigated whether tissue distribution in vivo can be predicted by use of binding data obtained in vitro. The selection of drugs represented a broad spectrum of physicochemical and pharmacokinetic properties thought to be important for distribution of drugs in vivo. The extent of binding to plasma and to tissue-homogenates of rabbits was determined in vitro. The drug concentrations in plasma, liver, lungs, kidneys, and skeletal muscle of rabbits were determined in vivo after i.v. administration of the drug. The tissue-plasma partition ratios measured in vivo were compared with the theoretical tissue-plasma partition ratios calculated from the in vitro binding data. For all drugs investigated the muscle-plasma partition ratio could be reasonably well predicted by the in vitro binding data. In liver, lungs, and kidneys good agreement was found between measured and predicted tissue-plasma ratio for anionic drugs; marked differences, however, were observed between measured and predicted tissue-plasma ratios of lipophilic cationic drugs. A significant correlation was found between binding of drugs to muscle tissue in vitro and the volume of distribution of the unbound drug (Vf), opening the possibility to approximate Vf from in vitro binding studies with rabbit muscle tissue.