Takamizawa Ren, Hotta Kazuki, Fujii Yutaka, Ikegami Ryo, Hitosugi Naoki, Inoue Tatsuro, Tamiya Hajime, Tsubaki Atsuhiro
Institute for Human Movement and Medical Sciences, Niigata University of Health and Welfare, Niigata, Niigata, Japan.
Department of Rehabilitation, Kitasato University School of Allied Health Sciences, Sagamihara, Kanagawa, Japan.
Microcirculation. 2024 Aug;31(6):e12870. doi: 10.1111/micc.12870. Epub 2024 May 28.
This study aimed to clarify the effect of Type I diabetes (DIA) on transcapillary PO gradients, which are oxygen-driving factors between the blood and the interstitium, in the contracting muscle of rats.
Wistar male rats were divided into the diabetic (streptozocin i.p.) and sham groups. Microvascular and interstitial PO were measured in the extensor digitorum longus muscle during electrical stimulation-induced muscle contraction, using the phosphorescence quenching method. Transcapillary PO gradient, ΔPO, was calculated as microvascular minus interstitial PO.
Resting microvascular PO was higher in the diabetic group than in the sham group (6.3 ± 1.7 vs. 4.7 ± 0.9 mmHg, p < 0.05) and remained for 180 s. Interstitial PO from rest to muscle contraction did not differ between the groups. The ΔPO was higher in the diabetic group than in the sham group at rest and during muscle contraction (4.03 ± 1.42 vs. 2.46 ± 0.90 mmHg at rest; 3.67 ± 1.51 vs. 2.22 ± 0.65 mmHg during muscle contraction, p < 0.05). Marked muscle atrophy was observed in the diabetic group.
DIA increased microvascular and transcapillary PO gradients in the skeletal muscle. The enhanced PO gradients were maintained from rest to muscle contraction in diabetic muscle.
本研究旨在阐明I型糖尿病（DIA）对大鼠收缩肌肉中跨毛细血管PO梯度的影响，跨毛细血管PO梯度是血液与间质之间的氧驱动因素。
将雄性Wistar大鼠分为糖尿病组（腹腔注射链脲佐菌素）和假手术组。在电刺激诱导的肌肉收缩过程中，采用磷光猝灭法测量趾长伸肌的微血管和间质PO。跨毛细血管PO梯度ΔPO通过微血管PO减去间质PO来计算。
糖尿病组静息微血管PO高于假手术组（6.3±1.7 vs. 4.7±0.9 mmHg，p<0.05），且持续180秒。两组从静息到肌肉收缩时的间质PO无差异。糖尿病组在静息和肌肉收缩时的ΔPO均高于假手术组（静息时4.03±1.42 vs. 2.46±0.90 mmHg；肌肉收缩时3.67±1.51 vs. 2.22±0.65 mmHg，p<0.05）。糖尿病组观察到明显的肌肉萎缩。
DIA增加了骨骼肌中的微血管和跨毛细血管PO梯度。在糖尿病肌肉中，从静息到肌肉收缩，增强的PO梯度持续存在。
