Microvascular permeability of skeletal muscle after eccentric contraction-induced muscle injury: in vivo imaging using two-photon laser scanning microscopy
| Autor: | David C. Poole, Kazuto Masamoto, Naoya Onodera, Bradley J. Behnke, Yutaka Kano, Akihiko Yamaguchi, Rie Shimotsu, Kazuki Hotta |
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| Rok vydání: | 2018 |
| Předmět: |
Male
0301 basic medicine Contraction (grammar) Physiology Muscle Fibers Skeletal Vascular permeability Microcirculation Capillary Permeability 03 medical and health sciences Two-photon excitation microscopy Physiology (medical) medicine Animals Eccentric Rats Wistar Laser Scanning Microscopy Microscopy Confocal Chemistry Skeletal muscle Electric Stimulation Rats 030104 developmental biology medicine.anatomical_structure Wounds and Injuries Preclinical imaging Muscle Contraction Biomedical engineering |
| Zdroj: | Journal of Applied Physiology. 125:369-380 |
| ISSN: | 1522-1601 8750-7587 |
| Popis: | Via modulation of endothelial integrity and vascular permeability in response to damage, skeletal muscle microvessels play a crucial permissive role in tissue leukocyte invasion. However, direct visual evidence of altered microvascular permeability of skeletal muscle has not been technically feasible, impairing mechanistic understanding of these responses. Two-photon laser scanning microscopy (TPLSM) allows three-dimensional in vivo imaging of skeletal muscle microcirculation. We hypothesized that the regulation of microvascular permeability in vivo is temporally related to acute inflammatory and regenerative processes following muscle injury. To test our hypothesis, tibialis anterior muscles of anesthetized male Wistar rats were subjected to eccentric contractions (ECCs) via electrical stimulation. The skeletal muscle microcirculation was imaged by an intravenously infused fluorescent dye (rhodamine B isothiocyanate-dextran) to assess microvascular permeability via TPLSM 1, 3, and 7 days after ECC. Immunohistochemistry on serial muscle sections was performed to determine the proportion of VEGF-A-positive muscle fibers in the damaged muscle. Compared with control rats, the volumetrically determined interstitial leakage of fluorescent dye (5.1 ± 1.4, 5.3 ± 1.2 vs. 0.51 ± 0.14 μm3 × 106; P < 0.05, days 1 and 3, respectively, vs. control) and percentage of VEGF-A-positive fibers in the damaged muscle (10 ± 0.4%, 22 ± 1.1% vs. 0%; days 1 and 3, respectively, vs. control) were significantly higher on days 1 and 3 after ECC. The interstitial leakage volume returned to control by day 7. These results suggest that microvascular hyperpermeability assessed by in vivo TPLSM imaging is associated with ECC-induced muscle damage and increased VEGF expression. NEW & NOTEWORTHY This investigation employed a novel in vivo imaging technique for skeletal muscle microcirculation using two-photon laser scanning microscopy that enabled microvascular permeability to be assessed by four-dimensional image analysis. By combining in vivo imaging and histological analysis, we found the temporal profile of microvascular hyperpermeability to be related to that of eccentric contraction-induced skeletal muscle injury and pronounced novel myocyte VEGF expression. |
| Databáze: | OpenAIRE |
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