Experimental Animals
Online ISSN : 1881-7122
Print ISSN : 1341-1357
ISSN-L : 0007-5124
Current issue
Displaying 1-14 of 14 articles from this issue
Original
  • Hong Wang, Qipu Feng, Chao Li, Huan Zhang, Yulan Peng
    2022 Volume 71 Issue 2 Pages 116-122
    Published: 2022
    Released on J-STAGE: May 20, 2022
    Advance online publication: November 19, 2021
    JOURNAL OPEN ACCESS

    Nonhuman primates share many developmental similarities with humans. As the world has recognized the rhesus monkey as a standard experimental monkey, studies of rhesus monkey are very important and essential. The purpose of this study was to use gray-scale ultrasound, color Doppler flow imaging (CDFI), and contrast-enhanced ultrasound (CEUS) to study the ultrasound appearance of adult healthy rhesus monkey kidneys and to investigate the relationship between renal ultrasound manifestations and body weight, gender, and the left and right kidneys. Thirty adult healthy rhesus monkeys were studied in the experiments. The size of the kidney and the length and diameter of the renal artery were measured. The peak systolic velocity (PSV), end diastolic velocity (EDV), and resistance index (RI) of the renal artery and intrarenal arteries were measured by CDFI. In CEUS, the time-intensity curve (TIC) was used to obtain microvascular perfusion parameters. There were significant differences in renal size, diameter and length of the renal artery, and hemodynamics of the renal arteries between the different weight groups. In CEUS, there were significant differences in area under curve (AUC), time from peak to one half (THP), intensity peak (PI), time to peak (TTP), mean transit time (MTT), and wash-in-slope (WIS) between the different weight groups. There were no statistical differences between genders or the left and right kidneys. Our study provides valuable reference data for the studies of the kidney and indicates that CEUS can be used to evaluate renal perfusion in rhesus monkeys.

    Download PDF (1677K)
  • Kazutaka Yamada, Wei-Guang Ding, Mariko Omatsu-Kanbe, Futoshi Toyoda, ...
    2022 Volume 71 Issue 2 Pages 123-130
    Published: 2022
    Released on J-STAGE: May 20, 2022
    Advance online publication: November 16, 2021
    JOURNAL OPEN ACCESS

    Pregnancy causes changes in the uterus, such as increased cell volume and altered water content. However, the mechanisms that protect the structure and maintain the function of uterine smooth muscle cells against these changes during pregnancy have not been clarified. This study focused on the volume-regulated anion channel (VRAC), which opens with cell swelling under low osmotic pressure and releases Cl ions and various organic osmolytes to resist cell swelling and regulates a wide range of biological processes such as cell death. In this study, myometrial smooth muscle (MSM) tissues and cells (MSMCs) were collected from non-pregnant and pregnant mice. Using western blotting and immunocytochemistry, leucine-rich repeat containing protein 8A (LRRC8A), an essential membrane protein that constitutes part of the VRAC, was determined to be diffused throughout MSMCs including in the cell membrane. Patch-clamp experiments were performed to investigate the electrophysiology of swelling-induced Cl currents (ICl, swell) mediated by the VRAC. No significant changes between non-pregnancy and pregnancy groups were observed in either the expression density of LRRC8A or the current density of ICl, swell, however the presence of LRRC8A on the cell membrane was significantly increased in the third trimester of pregnancy compared to the non-pregnancy. This study suggests that the VRAC may play a role, such as maintaining cellular homeostasis in the pregnant MSM.

    Download PDF (2167K)
  • Terumi Yurimoto, Takayuki Mineshige, Haruka Shinohara, Takashi Inoue, ...
    2022 Volume 71 Issue 2 Pages 131-138
    Published: 2022
    Released on J-STAGE: May 20, 2022
    Advance online publication: November 18, 2021
    JOURNAL OPEN ACCESS
    Supplementary material

    In veterinary medicine, blood transfusion is commonly performed on companion animals. The common marmoset is a small nonhuman primate with increasing popularity as an animal model in biomedical research. Because of its small whole blood volume, the marmoset is at high risk of exsanguination, and blood transfusion is required to care for life-threatening bleeding. However, few clinical evaluations exist on transfusions for marmosets. This study performed whole blood transfusion with cross-matching on nine marmosets and surveyed the therapeutic effects. Recipients included clinical cases with persistent bleeding, anemia, and coma, as well as animals subjected to postoperative bleeding prophylaxis. Donors were selected from healthy marmosets, including littermates. Cross-match assay before transfusion were all negative, and recipients showed no visible signs of transfusion-related adverse reactions. Whole blood transfusions caused hemostasis and successful recovery in bleeding marmosets, including long-term improvement of anemia cases. Our results indicated that blood transfusion is effective for marmosets with severe anemia and persistent hemorrhage from both non-experimental and surgical causes. Furthermore, DNA sequencing for blood-group classification revealed that all subject marmosets were type A, suggesting that the risk of blood type mismatch may be low in this species.

    Download PDF (1316K)
  • Jia-Sheng Rao, Can Zhao, Shu-Sheng Bao, Ting Feng, Meng Xu
    2022 Volume 71 Issue 2 Pages 139-149
    Published: 2022
    Released on J-STAGE: May 20, 2022
    Advance online publication: November 16, 2021
    JOURNAL OPEN ACCESS

    Clinical evaluations of long-term outcomes in the early-stage spinal cord injury (SCI) focus on macroscopic motor performance and are limited in their prognostic precision. This study was designed to investigate the sensitivity of the magnetic resonance imaging (MRI) indexes to the data-driven gait process after SCI. Ten adult female rhesus monkeys were subjected to thoracic SCI. Kinematics-based gait examinations were performed at 1 (early stage) and 12 (chronic stage) months post-SCI. The proportion of stepping (PS) and gait stability (GS) were calculated as the outcome measures. MRI metrics, which were derived from structural imaging (spinal cord cross-sectional area, SCA) and diffusion tensor imaging (fractional anisotropy, FA; axial diffusivity, λ//), were acquired in the early stage and compared with functional outcomes by using correlation analysis and stepwise multivariable linear regression. Residual tissue SCA at the injury epicenter and residual tissue FA/remote normal-like tissue FA were correlated with the early-stage PS and GS. The extent of lesion site λ///residual tissue λ// in the early stage after SCI was correlated with the chronic-stage GS. The ratios of lesion site λ// to residual tissue λ// and early-stage GS were predictive of the improvement in the PS at follow-up. Similarly, the ratios of lesion site λ// to residual tissue λ// and early-stage PS best predicted chronic GS recovery. Our findings demonstrate the predictive power of MRI combined with the early data-driven gait indexes for long-term outcomes. Such an approach may help clinicians to predict functional recovery accurately.

    Download PDF (3311K)
  • Kohei Kawakami, Hiroyuki Matsuo, Naoyo Kajitani, Takaya Yamada, Ken-ic ...
    2022 Volume 71 Issue 2 Pages 150-160
    Published: 2022
    Released on J-STAGE: May 20, 2022
    Advance online publication: November 16, 2021
    JOURNAL OPEN ACCESS

    Housing conditions can affect the well-being of laboratory animals and thereby affect the outcomes of experiments. The appropriate environment is essential for the expression of natural behavior in animals. Here, we compared survival rates in four inbred mouse strains maintained under three different environmental conditions. Three mouse strains (C57BL/6J, C3H/HeN, and DBA/2J) housed under environmental enrichment (EE) conditions showed improved survival; however, EE did not alter the survival rate of the fourth strain, BALB/c. None of the strains showed significant differences in body weights or plasma corticosterone levels in the three environmental conditions. For BALB/c mice, the rates of debility were higher in the EE group. Interestingly, for C57BL/6J and C3H/HeN mice, the incidence of animals with alopecia was significantly lower in the EE groups than in the control group. It is possible that the enriched environment provided greater opportunities for sheltering in a secure location in which to avoid interactions with other mice. The cloth mat flooring used for the EE group was bitten and chewed by the mice. Our findings suggest that depending on the mouse strains different responses to EE are caused with regard to health and survival rates. The results of this study provide basic data for further studies on EE.

    Download PDF (2799K)
  • Yasuyuki Asada, Shinya Koshinuma, Masaki Mikami, Yuuki Shirai, Yoshisa ...
    2022 Volume 71 Issue 2 Pages 161-172
    Published: 2022
    Released on J-STAGE: May 20, 2022
    Advance online publication: November 18, 2021
    JOURNAL OPEN ACCESS

    In oral surgery, tissue loss may occur in some cases, resulting in bone exposure and subsequent wound infection and possible scar formation during secondary healing. In this study, Terudermis® Artificial Dermis (AD-T), a dermal defect graft made from processed bovine dermis collagen and gelatin sponge (GS) were used as dressings on 100-mm2 wounds with exposed bone on the heads of rats. For the control group, the wound was left exposed. The wound-healing efficacy of the treatment was compared macroscopically and histologically among the three groups at 1, 2, and 4 weeks after surgery. Complete wound healing was achieved faster in the AD-T group than in the GS group, and osteoblasts appeared on the bone surface, indicating accelerated bone remodeling. Furthermore, in the AD-T group, there was an increased production of newly formed blood vessels, fibroblasts and osteoblasts positive for anti-cortactin antibodies, which are believed to contribute to wound healing. Our findings suggest that AD-T is better than GS as a wound dressing material.

    Download PDF (3772K)
  • Nan Shi, Wei Xia, Ketong Ji, Yiwei Feng, Hua Li, Guangyao He, Anzhou T ...
    2022 Volume 71 Issue 2 Pages 173-183
    Published: 2022
    Released on J-STAGE: May 20, 2022
    Advance online publication: December 01, 2021
    JOURNAL OPEN ACCESS
    Supplementary material

    The immune response plays a key role in the disease development of the organism, while immune function serves as an important indicator for animal models evaluation. The tree shrew (Tupaia belangeri chinensis), as a new laboratory animal with a close genetic relationship with primates, has been used to construct various disease models. However, the immune system of tree shrews, especially anatomical descriptions of lymph nodes, is still relatively unknown. In this study, a total of 16 different lymph nodes were identified, including superficial lymph nodes and deep lymph nodes. Superficial lymph nodes were located in the head and neck region (submandibular lymph node, parotid lymph node, deep and superficial cervical lymph nodes) and at the forelimb (axillary and accessory axillary lymph nodes, subscapular lymph node) and hindlimb (popliteal, sciatic, and inguinal lymph nodes). Deep lymph nodes comprise mediastinal lymph nodes located in thoracic cavity and abdominal lymph nodes that are mainly located in each mesentery (mesenteric, gastric, pancreatic-duodenal, renal lymph nodes) or along the major vessels (iliac lymph nodes). In addition, we described the spleen and thymus of the tree shrew, as well as two lymphoid tissues in the top wall of the nasal cavity and the oropharynx. This study mainly describes the tree shrew immune system from an anatomical and histopathological perspective and provides fundamental research references for the establishment of various animal models of tree shrews.

    Download PDF (12576K)
  • Hermawan Wibisono, Kazuomi Nakamura, Fuminori Taniguchi, Misako Seno, ...
    2022 Volume 71 Issue 2 Pages 184-192
    Published: 2022
    Released on J-STAGE: May 20, 2022
    Advance online publication: November 25, 2021
    JOURNAL OPEN ACCESS
    Supplementary material

    The pathogenesis of endometriosis has not been fully elucidated. We focused on the behavior of the ectopic endometrium, that is, the origin of the endometriotic lesion, before adhering to the peritoneal cavity. To observe lesion formation in the very early phase, we developed a novel endometriosis animal model using bioluminescence technology. We established a new transgenic mouse that expressed Emerald luciferase (ELuc) under the control of the CAG promoter. This transgenic mouse, called the CAG-ELuc mouse, showed strong bioluminescence emission; we succeeded in tracing the lesion location by the emission of ELuc. The accuracy of tracing by ELuc was high (57.7–100% of correspondence) and depended on the dosage of E2 administration. In the very early phase after transplantation, the process of lesion formation can be observed non-invasively and chronologically. We have verified that the preferred location of the uterus (transplanted grafts) was fixed immediately after the transplantation of the grafts.

    Download PDF (3427K)
  • Yanglong Li, Xianji Piao, Tiance Xu, Binbin Zhang, Xionghu Shen, Xian ...
    2022 Volume 71 Issue 2 Pages 193-203
    Published: 2022
    Released on J-STAGE: May 20, 2022
    Advance online publication: December 01, 2021
    JOURNAL OPEN ACCESS

    Granulocyte colony-stimulating factor (G-CSF) has been reported to exert a protective effect against secondary brain damage, but the underlying mechanisms remain unknown. We explored the ability of G-CSF to protect the brain from injury in a rat autologous blood-induced model of intracerebral hemorrhage (ICH), with a special focus on the anti-inflammation effect. An ICH was induced in 8-week-old male rats by an infusion of autologous blood, and the rats were then randomly assigned to five treatment groups: sham, ICH, and ICH+ low-dose (25 µg/kg), middle-dose (50 µg/kg), and high-dose (75 µg/kg) G-CSF. We then evaluated the levels of brain inflammation-related genes and proteins. The levels of tumor-necrosis factor-alpha (TNF-α) and interleukin-6 (IL-6) mRNA increased between days 1 and 14 post-ICH, with the highest expression on day 3. These changes were rectified by G-CSF in a dose-dependent manner. At day 3 post-injury, an elevation of the nuclear factor-kappa B (NF-κB) p65 protein level and a reduction of the inhibitor of NF-κB alpha (IκBα) protein level were observed; G-CSF treatment exerted a beneficial effect on both protein expressions. The expressions of inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) proteins were increased; these changes were rectified by the highest dose of G-CSF. The brain-protecting effects of G-CSF are likely to be attributable, at least in part, to attenuation of the TNF-α, IL-6, iNOS, and COX-2 expressions induced by NF-κB activation in the brain tissues of this autologous blood-induced ICH rat model.

    Download PDF (2117K)
  • Xinhong Wang, Liting Yan, Yinghua Tang, Xiaoxi He, Xiaomin Zhao, Weiji ...
    2022 Volume 71 Issue 2 Pages 204-213
    Published: 2022
    Released on J-STAGE: May 20, 2022
    Advance online publication: November 25, 2021
    JOURNAL OPEN ACCESS
    Supplementary material

    Hepatocyte growth factor (HGF) has been implicated in inhibiting diverse types of inflammation. Oral traumatic ulceration (OTU) is a common disease of the oral mucosa, and inflammation is the main process for ulcer healing. This study aimed to explore the expression of HGF in oral ulcers and its role in ulcer inflammation. The saliva of 14 recurrent alphous stomatitis (RAS) patients, 18 OTU patients and 17 healthy controls was collected. Traumatic ulcers of the left mucosa were observed in 42 wild-type (WT) and 42 HGF-overexpressing transgenic (HGF-Tg) mice. Histological scores, inflammatory cell expression and serum cytokine expression were measured and analyzed on the 5th day. The HGF protein level in ulcer-affected human saliva was 9.3-fold higher than that in healthy saliva. The HGF protein levels in RAS and OTU saliva were 14- and 5.7-fold higher, respectively, than those in healthy saliva. Traumatic ulcers enhanced HGF expression in ulcer-affected oral mucosa and in the blood of C57BL/6 mice by 1.21- and 1.40-fold, respectively. In HGF-Tg mouse traumatic ulcers, HGF expression was 1.34-fold higher than that in wild-type mice. HGF-Tg mice had lower weight loss, less ulcer area and lower histopathology scores than WT mice. The results from immunohistochemistry, flow cytometry and serum cytokine analysis showed that HGF-Tg animals presented fewer Ly6G-positive neutrophils and higher levels of circulating inflammatory cytokines. HGF overexpression alleviated weight loss, ulcer area and inflammation, suggesting the role of HGF in promoting the healing of oral ulcers.

    Download PDF (3904K)
  • Kenta Nakano, Yukiko Shimizu, Tetsuya Arai, Taketo Kaneko, Tadashi Oka ...
    2022 Volume 71 Issue 2 Pages 214-223
    Published: 2022
    Released on J-STAGE: May 20, 2022
    Advance online publication: December 07, 2021
    JOURNAL OPEN ACCESS
    Supplementary material

    Technique for Animal Knockout system by Electroporation (TAKE) is a simple and efficient method to generate genetically modified (GM) mice using the clustered regularly interspaced short palindromic repeat (CRISPR)/CRISPR-associated protein 9 (Cas9) systems. To reinforce the versatility of electroporation used for gene editing in mice, the electric condition was optimized for vitrified-warmed mouse embryos, and applied to the fresh embryos from widely used inbred strains (C57BL/6NCr, BALB/cCrSlc, FVB/NJcl, and C3H/HeJJcl). The electric pulse settings (poring pulse: voltage, 150 V; pulse width, 1.0 ms; pulse interval, 50 ms; number of pulses, +4; transfer pulse: voltage, 20 V; pulse width, 50 ms; pulse interval, 50 ms; number of pulses, ±5) were optimal for vitrified-warmed mouse embryos, which could efficiently deliver the gRNA/Cas9 complex into the zygotes without zona pellucida thinning process and edit the target locus. These electric condition efficiently generated GM mice in widely used inbred mouse strains. In addition, electroporation using the electrode with a 5 mm gap could introduce more than 100 embryos within 5 min without specific pretreatment and sophisticated technical skills, such as microinjection, and exhibited a high developmental rate of embryos and genome-editing efficiency in the generated offspring, leading to the rapid and efficient generation of genome editing mice. The electric condition used in this study is highly versatile and can contribute to understanding human diseases and gene functions by generating GM mice more easily and efficiently.

    Download PDF (3051K)
  • Cebrail Gursul, Adalet Ozcicek, Mustafa Ozkaraca, Ali Sefa Mendil, Tah ...
    2022 Volume 71 Issue 2 Pages 224-230
    Published: 2022
    Released on J-STAGE: May 20, 2022
    Advance online publication: December 15, 2021
    JOURNAL OPEN ACCESS

    The methanol metabolite that causes hepatotoxicity is formic acid, generating reactive oxygen radical formation and cell damage. Carvacrol is an antioxidant monoterpenic phenol produced from Thymus vulgaris. This study aimed to investigate the effects of carvacrol on methanol-induced oxidative liver damage in rats. Eighteen rats were divided into three groups. Methotrexate was administered orally for 7 days to methotrexate+methanol (MTM) and methotrexate+methanol+carvacrol (MMC) groups. Methotrexate was given before methanol to cause methanol poisoning. Distilled water was given to the healthy group (HG) as a solvent. At the end of the 7th day, 20% methanol was administered orally at a dose of 3 g/kg to the MTM and MMC groups. Four hours after methanol administration, 50 mg/kg carvacrol was injected intraperitoneally into the MMC group. Animals were sacrificed 8 h after carvacrol injection. Biochemical markers were studied in the excised liver tissue and blood serum samples, and histopathological evaluations were made. Severe hemorrhage, hydropic degeneration, pycnosis, and mononuclear cell infiltration were observed in the liver of the MTM group. Additionally, the levels of malondialdehyde (MDA), total oxidant status (TOS), alanine aminotransferase (ALT), and aspartate aminotransferase (AST) were significantly higher, and total glutathione (tGSH) and total antioxidant status (TAS) were significantly lower in the MTM group compared to HG (P<0.001). Carvacrol prevented the increase in MDA, TOS, ALT and AST levels with methanol and the decrease in tGSH and TAS levels (P<0.001), and alleviated the histopathological damage. Carvacrol may be useful in the treatment of methanol-induced liver damage.

    Download PDF (1749K)
  • Daniel Kiefer, Lukas M. Müller-Wirtz, Felix Maurer, Tobias Hüppe, Alex ...
    2022 Volume 71 Issue 2 Pages 231-239
    Published: 2022
    Released on J-STAGE: May 20, 2022
    Advance online publication: December 08, 2021
    JOURNAL OPEN ACCESS
    Supplementary material

    Rats are commonly used animals for laboratory experiments and many experiments require general anesthesia. However, the lack of published and reproducible intravenous anesthesia protocols for rats results in unnecessary animal use to establish new anesthesia techniques across institutions. We therefore developed an anesthesia protocol with propofol, ketamine, and rocuronium for mechanically ventilated rats, and evaluated vital parameters and plasma concentrations. 15 male Sprague-Dawley rats underwent inhalation induction with sevoflurane and tracheal, venous and arterial cannulation. After established venous access, sevoflurane was substituted by propofol and ketamine (ketofol). Rocuronium was added under mechanical ventilation for 7 h. Drug dosages were stepwise reduced to prevent accumulation. All animals survived the observation period and showed adequate depth of anesthesia. Mean arterial pressure and heart rate remained within normal ranges. Median propofol plasma concentrations remained stable: 1, 4, 7 h: 2.0 (interquartile range (IQR): 1.8–2.2), 2.1 (1.8–2.2), 1.8 (1.6–2.1) µg/ml, whereas median ketamine concentrations slightly differed after 7 h compared to 1 h: 1, 4, 7 h: 3.7 (IQR: 3.5–4.5), 3.8 (3.3–4.1), 3.8 (3.0–4.1) µg/ml. Median rocuronium plasma concentrations were lower after 4 and 7 h compared to 1 h: 1, 4, 7 h: 3.9 (IQR: 3.5–4.9), 3.2 (2.7–3.3), 3.0 (2.4–3.4) µg/ml. Our anesthesia protocol provides stable and reliable anesthesia in mechanically ventilated rats for several hours.

    Download PDF (874K)
  • Ikuo Miura, Yoshiaki Kikkawa, Shumpei P. Yasuda, Akiko Shinogi, Daiki ...
    2022 Volume 71 Issue 2 Pages 240-251
    Published: 2022
    Released on J-STAGE: May 20, 2022
    Advance online publication: December 28, 2021
    JOURNAL OPEN ACCESS
    Supplementary material

    Forward genetics is a powerful approach based on chromosomal mapping of phenotypes and has successfully led to the discovery of many mouse mutations in genes responsible for various phenotypes. Although crossing between genetically remote strains can produce F2 and backcross mice for chromosomal mapping, the phenotypes are often affected by background effects from the partner strains in genetic crosses. Genetic crosses between substrains might be useful in genetic mapping to avoid genetic background effects. In this study, we investigated single nucleotide polymorphisms (SNPs) available for genetic mapping using substrains of C57BL/6 and BALB/c mice. In C57BL/6 mice, 114 SNP markers were developed and assigned to locations on all chromosomes for full utilization for genetic mapping using genetic crosses between the C57BL/6J and C57BL/6N substrains. Moreover, genetic differences were identified in the 114 SNP markers among the seven C57BL/6 substrains from five production breeders. In addition, 106 SNPs were detected on all chromosomes of BALB/cAJcl and BALB/cByJJcl substrains. These SNPs could be used for genotyping in BALB/cJ, BALB/cAJcl, BALB/cAnNCrlCrlj, and BALB/cCrSlc mice, and they are particularly useful for genetic mapping using crosses between BALB/cByJJcl and other BALB/c substrains. The SNPs characterized in this study can be utilized for genetic mapping to identify the causative mutations of the phenotypes induced by N-ethyl-N-nitrosourea mutagenesis and the SNPs responsible for phenotypic differences between the substrains of C57BL/6 and BALB/c mice.

    Download PDF (3213K)
feedback
Top