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Start Over Topic animals Topic guinea pigs Publisher biomed central
5 results

1. Comparative study of hyperpolarization-activated currents in pulmonary vein cardiomyocytes isolated from rat, guinea pig, and rabbit

Author

Takayoshi Ohba, Kyoichi Ono, Yosuke Okamoto, Daichi Takagi, and Hiroshi Yamamoto

Subjects
Cell physiology, Physiology, Guinea Pigs, Action Potentials, Cesium, Pharmacology, Pulmonary vein, Guinea pig, Hyperpolarization-activated cation current, Species Specificity, Hyperpolarization-activated Cl− current, Myocyte, Animals, Myocytes, Cardiac, Ion channel, Original Paper, Chemistry, Automaticity, Diastolic depolarization, Hyperpolarization (biology), Atrial fibrillation, Rats, Electrophysiology, Barium, Pulmonary Veins, Rabbits, Cadmium
Abstract

Pulmonary vein (PV) cardiomyocytes have the potential to generate spontaneous activity, in contrast to working myocytes of atria. Different electrophysiological properties underlie the potential automaticity of PV cardiomyocytes, one being the hyperpolarization-activated inward current (Ih), which facilitates the slow diastolic depolarization. In the present study, we examined pharmacological characteristics of the Ih of PV cardiomyocytes in rat, guinea pig and rabbit. The results showed that guinea pig and rat PV cardiomyocytes possessed sizeable amplitudes of the Ih, and the Ih of guinea pig was suppressed by Cs+, a blocker of the hyperpolarization-activated cation current. However, the Ih of rat was not suppressed by Cs+, but by Cd2+, a blocker of the Cl− current. The current density of the Ih of rabbit PV cardiomyocytes was significantly smaller than those of other species. This suggests that the ion channels that carry the Ih of PV cardiomyocytes differ among the animal species.

Published
2020

2. Defining matrix Gla protein expression in the Dunkin-Hartley guinea pig model of spontaneous osteoarthritis.

Author

Ma, Xun, Zhang, Zhan, Kang, Xinyuan, Deng, Chunbo, Sun, Yingwei, Li, Yanjun, Huang, Desheng, and Liu, Xueyong

Subjects
PROTEINS, MATRIX Gla protein, PROTEOMICS, OSTEOARTHRITIS, ARTICULAR cartilage, CALCIUM-binding proteins, GUINEA pigs, ANIMALS
Abstract

Background: Matrix Gla (γ-carboxyglutamate) protein (MGP) is considered a strong inhibitor of ectopic calcification, and it has been associated with OA severity, although not conclusively. We utilized male Dunkin-Hartley (DH) guinea pigs to investigate the expression of MGP throughout aging and disease pathogenesis in a spontaneous model.Method: Twenty-five male DH guinea pigs were obtained and nurtured to several timepoints, and then randomly and equally divided by age into five subgroups (1-, 3-, 6-, 9-, and 12-months, with the 1-month group as the reference group). DH guinea pigs in each group were euthanized at the designated month-age and the left or right medial tibial plateaus cartilages were randomly excised. OA severity was described by modified Mankin Score (MMS) at microscopy (Safranin O/Fast Green stain). Proteomic evaluation using isobaric tags for relative and absolute quantification (iTRAQ) was performed to validate the age-related changes in the MGP profiles, and immunohistochemistry (IHC) methods were applied for semi-quantitative determination of MGP expression in articular cartilage.Results: The histopathologic findings validated the increasing severity of cartilage degeneration with age in the DH guinea pigs. The MMS showed significant, stepwise (every adjacent comparison P < 0.05) disease progression with month-age. The iTRAQ indicated that MGP levels increased significantly with advancing age (P < 0.05), as supported by the IHC result (P < 0.05).Conclusion: Increased expression of MGP in male DH guinea pigs was present throughout aging and disease progression and may be link to increased OA severity. Further studies are needed to investigate and confirm the association between MGP levels and OA severity. [ABSTRACT FROM AUTHOR]

Published
2021
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3. Strontium ranelate causes osteophytes overgrowth in a model of early phase osteoarthritis.

Author

Jian-Guo Chu, Mu-Wei Dai, Yu Wang, Fa-Ming Tian, Hui-Ping Song, Ya-Ping Xiao, Li-Tao Shao, Ying-Ze Zhang, Liu Zhang, Chu, Jian-Guo, Dai, Mu-Wei, Wang, Yu, Tian, Fa-Ming, Song, Hui-Ping, Xiao, Ya-Ping, Shao, Li-Tao, Zhang, Ying-Ze, and Zhang, Liu

Subjects
STRONTIUM ranelate, BONE spurs, OSTEOARTHRITIS, CARTILAGE, OSTEOPOROSIS, ANIMAL experimentation, ANIMALS, BIOLOGICAL models, DIPHOSPHONATES, GUINEA pigs, METAPLASTIC ossification, SULFUR compounds, THERAPEUTICS
Abstract

Background: Osteoarthritis (OA) involves cartilage changes as well as modifications of subchondral bone and synovial tissues. Strontium ranelate (SR), an anti-osteoporosis compound, which is currently in phase III clinical trial for treatment of OA. Evidences suggest that SR preferably deposited in osteophyte, other than in subchondral bone in early phase of OA. This phenomenon raises concern about its utility for OA treatment as a disease-modifying drug. To evaluate the effect of SR on cartilage, subchondral bone mass and subchondral trabecular bone structure in medial meniscectomized (MNX) guinea pigs.Method: Thirty-six 3-month-old male Dunkin Hartley albino guinea pigs received either sham or medial meniscectomy operations. One week after the procedure, meniscectomized animals began 12 weeks of SR (625 mg/kg, daily) treatment by oral gavage for MNX + SR group, or normal saline for MNX + V group. All animals were euthanized 12 weeks later, cartilage degeneration and subchondral bone micro-architecture was analyzed.Results: Both OARSI scores (P = 0.523 for marcoscopic scores, P = 0.297 for histological scores) and Cartilage thickness (P = 0.335) in MNX + SR group were comparable to MNX + V group. However, osteophyte sizes were larger in MNX + SR group (P = 0.014), and collapsed osteophytes in MNX + SR group (7 by 12) were significantly more than in MNX + V group (1 by 12) (P = 0.027), while immunohistochemistry indicates catabolic changes in osteophyte/plateau junction. Micro-CT analysis showed bone mineral density (BMD) (P = 0.001), bone volume fraction (BV/TV) (P = 0.008), trabecular spacing (Tb.Sp) (P = 0.020), trabecular thickness (Tb.Th) (P = 0.012) and structure model index (SMI) (P = 0.005) levels to be significantly higher in the MNX + SR group than in the MNX + V group.Conclusions: SR (625 mg/kg/day) did not protect cartilage from degeneration in MNX guinea pigs but subchondral bone was significantly enhanced. In early phase OA, SR administration causes osteophyte overgrowth, which may be related to incorporation into mineralizing osteophytes. This adverse effect is important for future studies of SR in OA. [ABSTRACT FROM AUTHOR]

Published
2017
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4. N-truncated Aβ4–x peptides in sporadic Alzheimer’s disease cases and transgenic Alzheimer mouse models

Author

Wirths, Oliver, Walter, Susanne, Kraus, Inga, Klafki, Hans W., Stazi, Martina, Oberstein, Timo J., Ghiso, Jorge, Wiltfang, Jens, Bayer, Thomas A., and Weggen, Sascha

Subjects
Male, Plaque, Amyloid, lcsh:RC346-429, APP protein, human, pathology [Alzheimer Disease], Amyloid beta-Protein Precursor, Medizinische Fakultät, pathology [Brain], metabolism [Amyloid beta-Protein Precursor], pathology [Down Syndrome], 5XFAD, APP/PS1KI, Alzheimer’s disease, Immunohistochemistry, Mouse model, N-truncated Amyloid-β, Postmortem, Aged, 80 and over, metabolism [Cerebral Amyloid Angiopathy], metabolism [Presenilin-1], Brain, genetics [Presenilin-1], immunology [Amyloid beta-Peptides], genetics [Amyloid beta-Protein Precursor], metabolism [Down Syndrome], metabolism [Alzheimer Disease], Guinea Pigs, metabolism [Amyloid beta-Peptides], Enzyme-Linked Immunosorbent Assay, Mice, Transgenic, methods [Immunohistochemistry], pathology [Cerebral Amyloid Angiopathy], Antibodies, lcsh:RC321-571, PSEN1 protein, human, Alzheimer Disease, Presenilin-1, Animals, Humans, ddc:610, pathology [Plaque, Amyloid], lcsh:Neurosciences. Biological psychiatry. Neuropsychiatry, lcsh:Neurology. Diseases of the nervous system, Aged, Amyloid beta-Peptides, Research, metabolism [Plaque, Amyloid], Mice, Inbred C57BL, Cerebral Amyloid Angiopathy, Disease Models, Animal, metabolism [Brain], Down Syndrome
Abstract

Background The deposition of neurotoxic amyloid-β (Aβ) peptides in plaques in the brain parenchyma and in cerebral blood vessels is considered to be a key event in Alzheimer’s disease (AD) pathogenesis. Although the presence and impact of full-length Aβ peptides such as Aβ1–40 and Aβ1–42 have been analyzed extensively, the deposition of N-terminally truncated Aβ peptide species has received much less attention, largely because of the lack of specific antibodies. Methods This paper describes the generation and characterization of novel antibodies selective for Aβ4–x peptides and provides immunohistochemical evidence of Aβ4–x in the human brain and its distribution in the APP/PS1KI and 5XFAD transgenic mouse models. Results The Aβ4–x staining pattern was restricted mainly to amyloid plaque cores and cerebral amyloid angiopathy in AD and Down syndrome cases and in both AD mouse models. In contrast, diffuse amyloid deposits were largely negative for Aβ4–x immunoreactivity. No overt intraneuronal staining was observed. Conclusions The findings of this study are consistent with previous reports demonstrating a high aggregation propensity of Aβ4–x peptides and suggest an important role of these N-truncated Aβ species in the process of amyloidogenesis and plaque core formation.

Published
2017

5. Pulsed 980 nm short wavelength infrared neural stimulation in cochlea and laser parameter effects on auditory response characteristics

Author

Jianren Lu, Lan Tian, Chen Li, Xiaofei Li, Jingxuan Wang, and Lei Xu

Subjects
Optical fiber, Materials science, Infrared Rays, Guinea Pigs, Biomedical Engineering, Deafness, law.invention, Biomaterials, law, medicine, otorhinolaryngologic diseases, Animals, Radiology, Nuclear Medicine and imaging, Cochlear Nerve, Spiral ganglion, Cochlea, Optical Fibers, Neurons, Round window, Radiological and Ultrasound Technology, Research, Lasers, Cochlear nerve, Optical neural stimulation, General Medicine, Laser, medicine.anatomical_structure, Auditory brainstem response, Amplitude, Acoustic Stimulation, Optically evoked ABRs, Short-wavelength infrared (SWIR), sense organs, Biomedical engineering, Brain Stem
Abstract

Background Auditory neural stimulation with pulsed infrared radiation has been proposed as an alternative method to activate the auditory nerves in vivo. Infrared wavelengths from 1800–2150 nm with high water absorption were mainly selected in previous studies. However, few researchers have used the short-wavelength infrared (SWIR) for auditory nerve stimulation and limited pulse parameters variability has been investigated so far. Methods In this paper, we pioneered to use the 980 nm SWIR laser with adjustable pulse parameter as a stimulus to act on the deafened guinea pigs’ cochlea in vivo. Pulsed laser light was guided through the cochlear round window to irradiate the spiral ganglion cells via a 105 μm optical fiber, and then the laser pulse parameters variability and its influence to auditory response characteristics were studied. Results The results showed that the optically evoked auditory brainstem response (OABR) had a similar waveform to the acoustically induced ABR with click sound stimulus. And the evoked OABR amplitude had a positive correlation, while the OABR latency period showed a negative correlation, with the laser pulse energy increase. However, when holding the laser peak power constant, the pulse width variability ranged from 100 to 800 μs showed little influence on the evoked OABR amplitude and its latency period. Conclusions Our study suggests that 980 nm SWIR laser is an effective stimulus for auditory neurons activation in vivo. The evoked OABR amplitude and latency are highly affected by the laser pulse energy, while not sensitive to the pulse width variability in 100–800 μs range.

Published
2015