| 1. |
- Degens, Hans, et al.
(author)
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Post-operative effects on insulin resistance and specific tension of single skeletal muscle fibres
- 1999
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In: Clinical Science. - : Lippincott Williams & Wilkins. - 0143-5221 .- 1470-8736. ; 97:4, s. 449-455
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Journal article (peer-reviewed)abstract
- Surgery and accidental trauma are associated with a transient period of insulin resistance, substrate catabolism and muscle weakness. In the present study, we evaluated the changes in the force-generating capacity of chemically skinned single muscle fibresfollowing abdominal surgery. Biopsies of the m. vastus lateralis were obtained in three patients 1 day before and 3 or 6 days after surgery. Part of the biopsy was frozen for histochemical analysis of the fibre cross-sectional area (FCSA) and myofibrillar protein content, and another part was used for single-fibre contractile measurements. All patients developed insulin resistance following surgery. The maximum velocity of unloaded shortening of single muscle fibres did not change following surgery. The FCSA did not decrease after surgery, as determined either from histochemical sections or from singlefibres measured at a fixed sarcomere length of 2.76+/-0.09 microm (mean+/-S.D.). Further, the force-generating capacity of the single fibres, measured as maximal Ca(2+)-activated force (P(0)) or as P(0) normalized to FCSA (specific tension), remained unchanged, as did the myofibrillar protein content of the muscle. In conclusion, the muscle weakness associated with post-operative insulin resistance is not related to a decreased specifictension or a loss of myofibrillar proteins. Other potential cellular mechanisms underlying post-operative weakness are discussed.
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| 2. |
- Díaz, Miguel, Högskoleadjunkt, et al.
(author)
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Differential effects of resveratrol on the dilator responses of femoral arteries, ex vivo
- 2019
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In: Nitric oxide. - : Elsevier. - 1089-8603 .- 1089-8611. ; 92, s. 1-10
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Journal article (peer-reviewed)abstract
- Resveratrol is a plant-derived phytoalexin with antioxidant, anti-inflammatory and cardio-protective properties and may be a promising therapeutic intervention strategy in cardiovascular disease. Here, we investigated the acute direct effects of trans-resveratrol (RV), on acetylcholine (ACh)-induced and flow-mediated dilation (FMD) of isolated pressurized femoral arteries of young (4-month-old) and old (26-month-old) mice. Vessel exposure to RV enhanced ACh (0.01-1.0 mM)-induced dilation (p < 0.05), but not FMD (@ 5-10 μL⋅min-1) (p < 0.05) in both young and old mice. After RV incubation, acute nitric oxide (NO) production by cultured endothelial cells was increased in response to 0.01 mM ACh, but reduced by flow (5-10 μL⋅min-1; p < 0.05). In isolated femoral arteries from endothelial nitric oxide synthase knockout (eNOS-/-) mice, RV had no overall effect on flow mediated dilation, but potentiated ACh induced dilation, that was completely abolished by potassium channel blockers, Apamin and Tram 34 (p < 0.01). We demonstrate that the non-metabolised form of RV stimulates ACh-induced dilation via the NO and EDHF pathways, but not FMD by interaction with the cyclo-oxygenase pathway. Our findings have important implications in the use of RV (for both young and aged) under 'normal' non-diseased physiological states.
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