Influence of death struggle on the structural changes in chub mackerel muscle during chilled storage

ABSTRACT: Chub mackerel (34–35 cm, approximately 500 g), which were caught by fishing with a rod and line at the Bungo Channel, Oita prefecture, were rested overnight in a fish preserve and either killed by decapitation (control group) or allowed to struggle in air for 30 min (struggled group). Muscle samples were excised every 4 h, and measurements on breaking strength and histological observations were done for both groups. The breaking strength of muscle in the control group was significantly higher than that in the struggled group, whereby a decrease in breaking strength was delayed for 12 h compared to the struggled group. Light microscopy showed space extension among muscle cells in association with a decrease in breaking strength. Especially in the struggled group, the extended area was larger and the difference in area was significant at the time when breaking strength showed a significant difference. Using electron microscopy, the extended area showed cut and/or disappeared collagen fibrils. From these results, it was demonstrated that struggling to death promoted the degradation of collagen fibrils and the weakening of connective tissue and, resultantly, led to the faster softening of muscle of chub mackerel.     

Effect of hydrogen sulfide on myocardial fibrosis and PPARγ and NF-κB expression in rat model of diabetes

AIM: To explore the effects of hydrogen sulfide (H₂S) on the myocardial fibrosis in a rat model of diabetes and its mechanism.METHODS: Single intraperitoneal injection of streptozotocin (STZ) was utilized to establish a rat model of diabetes. Sodium hydrosulfide was used as an exogenous donor of hydrogen sulfide. Male SD rats were randomly divided into control group, STZ group, STZ+H₂S group and H₂S group. Eight weeks later, HE and VG staining methods were used to observe the collagen distribution and collagen volume fraction was measured by image analysis. The expression levels of type I collagen, PPARγ and NF-κB in the cardiac tissues were determined by Western blotting.RESULTS: Compared with control group, collagen distribution and the expression levels of type I collagen and NF-κB in the cardiac tissues were markedly increased (P<0.05), while PPARγ was significantly decreased in STZ group (P<0.05), but these indexes were reversed significantly in STZ+H₂S group (P<0.05). The expression levels of type I collagen, PPARγ and NF-κB had no significant difference between H₂S group and control group.CONCLUSION: Hydrogen sulfide attenuates cardiac fibrosis in diabetic rats, and its mechanism may be related to PPARγ-NF-κB signaling pathway.     

Effect of dipeptide on intestinal peptide transporter 1 gene expression: An evaluation using primary cultured chicken intestinal epithelial cells

Peptide transporter 1 (PepT1) is a transporter responsible for absorbing dipeptide and tripeptide in enterocytes and is upregulated by dipeptide in mammals. It has not been certain whether intestinal PepT1 expression is responsive to dipeptides in chickens because of the lack of in vitro study using the cultured enterocytes. This study established a primary culture model of chicken intestinal epithelial cells (IECs) in two-dimensional monolayer culture using collagen gel by which the response of chicken PepT1 gene expression to dipeptide stimuli was evaluated. The cultured chicken IECs showed the epithelial-like morphology attached in a patch-manner and exhibited positive expression of cytokeratin and epithelial cadherin, specific marker proteins of epithelial cells. Moreover, the chicken IECs exhibited the gene expression of intestinal cell type-specific marker, villin1, mucin 2, and chromogranin A, suggesting that the cultured IECs were composed of enterocytes as well as goblet and enteroendocrine cells. PepT1 gene expression was significantly upregulated by synthetic dipeptide, glycyl-l-glutamine, in the cultured IECs. From the results, we herein suggested that dipeptide is a factor upregulating PepT1 gene expression in chicken IECs.     

The influence of crossbreeding on collagen solubility and tenderness of Infraspinatus and Semimembranosus muscles of semi‐intensively reared young bulls

The aim of the present study was to investigate the effects of crossbreeding on collagen content and solubility, shear force (WBSF) and the eating quality of Infraspinatus (INF) and Semimembranosus (SM) muscles of young bulls and the relationships between collagen content and solubility, shear force and the eating quality of beef. The experimental material comprised muscles of crossbred young bulls (about 600 days old) of Polish Holstein‐Friesian (PHF) × Limousine (LM) (n = 10), PHF × Charolaise (CH) (n = 9), PHF × Hereford (HER) (n = 9) breeds. The crossbreeding influenced WBSF, aroma and taste, total, water‐soluble, acid‐soluble, total soluble and insoluble collagen content, as well as the acid‐soluble, total soluble and insoluble collagen proportions. WBSF was significantly negatively correlated with sensorial tenderness and water‐soluble collagen content. The eating quality of beef obtained from different crossbreds was similar; however, the meat from PHF × LM and PHF × HER bulls had lower WBSF values than PHF × CH bulls. © 2016 Japanese Society of Animal Science     

Models in vivo of wound healing in the horse and the role of growth factors

Abstract Wound models attempt to simulate the natural healing processes in wounds. However, all models have significant limitations due to the complexity of the tissue repair process. Much can be learned from wound models in vitro by the use of cell culture techniques. The horse can provide a suitable naturally occurring model of chronic wound healing because it has many similarities to wound healing encountered in human medicine. The tissue architecture was investigated with regard to extracellular matrix and growth factor distribution during wound healing and growth factors were consistently present in the wound area. Biochemical investigations revealed increased levels of hydroxyproline, collagen, and TGFβ1 in exuberant granulation tissue. Equine wound models were established in vitro using cell culture techniques and growth factors had significant effects on the growth of the cells and their ability to synthesize collagen. Two gelatinases (MMP-2 and MMP-9) were detected in the tissues and wound fluid samples investigated. Zusammenfassung Wundmodelle haben zum Ziel, die natürlichen Heilungsprozesse in Wunden zu simulieren. Allen Modellen sind durch den komplexen Gewebsheilungsprozess deutliche Grenzen gesetzt. Durch die Verwendung von Zellkulturtechniken kann von Wundmodellen in vitro viel abgeleitet werden. Das Pferd stellt wegen der vielen Ähnlichkeiten zur humanmedizinischen Wundheilung ein geeignetes Modell für chronische Wundheilung dar. Die Gewebsarchitektur wurde bezüglich der Verteilung von extrazellulärer Matrix und von Wachtumsfaktoren während der Wundheilung untersucht; Wachtsumsfaktoren waren ständig in der Wunde vorhanden. Biochemische Untersuchungen ergaben erhöhte Hydroxyprolin-, Kollagenund TGFβ1-Spiegel. Wundmodelle beim Pferd in vitro und Zellkulturtechniken wurden entwickelt; Wachstumsfaktoren hatten deutliche Wirkung auf die Zellen und ihre Fahigkeit zur Kollagensynthese. Zwei Gelatinasen (MMP-2 und MMP-9) wurden im Gewebe identifiziert und Wundflüssigkeitsproben untersucht. [Cochrane, C.A. Models in vivo of wound healing in the horse and the role of growth factors. (Wundheilungsmodelle in vivo beim Pferd und die Rolle von Wachstunisfaktoren). Veterinary Dermatology 1997; 8 : 259–272] Resumen Los modelos de heridas intentan estimular el proceso natural de curación de heridas. Sin embargo, todos 10s modelos presentan limitaciones considerables debido a la complejidad del proceso de curación de heridas. Se puede aprender mucho de modelos de heridas in vitro mediante el uso de técnicas de cultivo celular. El caballo puede suponer un modelo natural adecuado de curación crónica de heridas ya que se asemeja a la curación de heridas en medicina humana. Se investigó la arquitectura tisular en referencia a la matriz extracelular y la distribución de factores de crecimento viendo que los factores de crecimiento se encontraban presentes de forma constante en el área de la herida. Las investigaciones bioquímicas revelaron incremento en los niveles de hidroxiprolina, colágeno y TGFbl en tejido de granulación exhuberante. Se establecieron modelos in vitro de heridas equinas utilizando técnicas de cultivo celular y los factores de crecimiento tuvieron efectos significativos en el crecimiento de las células y su capacidad de sintetizar colágeno. Se detectaron dos gelatinasas (MMP-2 y MMP-9) en 10s tejidos y muestras de fluidos de las heridas investigadas. [Cochrane, C.A. Models in vivo of wound healing in the horse and the role of growth factors. (Modelos de curacion de heridas in vivo en el caballo y el papel de 10s factores de crecimiento). Veterinary Dermatology 1997; 8 : 259–272] Résumé Les modèles de plaies tentent de simuler les processus naturels de cicatrisation. Cependant tous les modèles ont des limitations significatives dues à la complexité des processus de réparation des tissus. Beaucoup peut être étudié sur des modèles de plaies in vitro suite à l'utilisation des techniques de culture cellulaire. Le cheval peut constituer un modèle nature1 fiable de cicatrisation chronique de plaie de par les nombreuses similarités qu'il partage avec la cicatrisation des plaies en médecine humaine. L'architecture tissulaire a étéétudiée concernant la matrice extracellulaire et la distribution des facteurs de croissance pendant la cicatrisation, et les facteurs de croissance se sont montrés présents de façon consistante dans la zone de la plaie. Des investigations biochimiques ont révélé une élévation des taux d'hydroxyproline, collagène, et TGFβ1 dans la granulation tissulaire exubérante. Des modèles équins de plaies ont étéétablis in vivo en utilisant des techniques de culture cellulaire et les facteurs de croissance ont montré des effets significatifs sur la croissance des cellules et leur capacité de synthétiser le collagène. Deux gélatinases (MMP-2 et MMP-9) ont été détectées dans les tissus et les échantillons de fluide des plaies ont été analysés. [Cochrane, C.A. Models in vivo of wound healing in the horse and the role of growth factors. (Modeles in vivo de cicatrisation des plaies chez le cheval et role des facteurs de croissance). Veterinary Dermatology 1997; 8 : 259–272]     

The effect of porcine hydrolysed collagen on gastric ulcer scores,gastric juice pH,gastrin and amino acid concentrations in horses

Gastric ulcers are common in horses. The purpose of this study was to test the effect of porcine hydrolysed collagen (PHC) on gastric ulcer scores and gastric juice pH in horses. We hypothesise that PHC-administration will result in improved gastric lesion scores and act synergistically with omeprazole to improve treatment efficacy. Thoroughbred horses (n = 10) were studied in a 2-period, 2-treatment crossover design, where the PHC (45 g) was administered twice daily. Horses were treated for 56 days. Gastroscopy was performed and gastric juice pH measured on Days 0, 14, 28, 42, 49 and 56. Nonglandular gastric ulcer number (NGN) and severity (NGS) and glandular ulcer number (GN) and glandular severity (GS) scores were assigned by an investigator masked to treatment and serum gastrin and amino acid concentrations. By Day 42, 2 weeks after discontinuing omeprazole treatment, NGN and NGS scores returned to pretreatment values and serum gastrin was higher when compared to values measured on Day 28. By Day 49, after the feed-deprivation period, NGN and NGS were similar to pretreatment values. By Day 56, mean NGN score was significantly lower in PHC-treated horses, compared to controls. Mean gastric juice pH significantly increased in both groups on Day 28 and the pH was significantly (P = 0.0127) higher in the PHC-treated horses. Serum amino acid concentrations were not significantly different 2 h after feeding PHC and hydroxyproline was not detected. Serum gastrin concentration did not increase 2 h after feeding in the PHC-fed horses. The PHC fed to horses enhanced the effects of omeprazole on increased gastric juice pH, inhibited gastrin secretion after feeding and resulted in fewer nonglandular ulcers after long-term feeding (56 days) in stall-confined horses undergoing intermittent feeding.     

Lipopolysaccharide induces expression of collagen VI in the rat lung

The involvement of the lung during the septic systemic inflammatory response elicited by administration of lipopolysaccharide (LPS) was investigated. Eight-week-old male Sprague–Dawley rats were injected i.p. with 15 mg/kg LPS. After 24 h, the lungs were excised to evaluate the cellular responses to LPS. Matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF) analysis revealed that type VI collagen (ColVI) was extremely upregulated during sepsis in the rat lung within the first 24 h of LPS administration. Upregulation of ColVI protein and its mRNA was demonstrated by Western blot analysis, real time PCR, and immunohistochemistry. To the best of our knowledge, this is the first report demonstrating the activation of ColVI in the rat lung at the early stage of systemic inflammation. Activation of ColVI might be involved in sepsis-mediated lung fibrosis at an early stage.     

Micro-computed tomography evaluation and pathological analyses of female rats with collagen-induced arthritis

Imaging techniques have been introduced to assess the efficacy and toxicity of developing pharmaceuticals. The purpose of this study was to perform a comprehensive characterization of collagen-induced arthritis (CIA) in rats using micro-computed tomography (micro-CT) and to compare the results with data from conventional pathological examination. Arthritis was induced by collagen in 24 female Wistar rats. Micro-CT and pathological analyses were performed to assess arthritis progression. Micro-CT analysis showed marked joint destruction occurring in a time-dependent manner following collagen administration. Bone volume was significantly decreased in the tibia at weeks 3 and 4 compared to week 0 (p < 0.05 and p < 0.01, respectively). Additionally, percent bone volume was significantly reduced in the tibia at week 4 compared to week 0 (p < 0.05). In contrast, bone surface/bone volume and trabecular separation were significantly increased in the tibia of the animals at week 4 compared to week 0 (p < 0.05). Severe joint destruction with extensive inflammation, erosion of cartilage and bone, and infiltration of inflammatory cells were observed in the knee joints of the collagen-treated rats. Taken together, micro-CT made it possible to quantify CIA lesions and should be performed with pathological examination in rats.