Sex differences in mitochondrial Ca2+ handling in mouse fast-twitch skeletal muscle in vivo
| Autor: | David C. Poole, Ryo Ikegami, Hiroaki Eshima, Yutaka Kano, Kazuyoshi Yagishita, Koji Hatakeyama, Daiki Watanabe |
|---|---|
| Rok vydání: | 2020 |
| Předmět: |
0301 basic medicine
SERCA Fast twitch muscle Physiology Chemistry Calcium handling Skeletal muscle Mitochondrial calcium uniporter Cell biology 03 medical and health sciences 030104 developmental biology 0302 clinical medicine medicine.anatomical_structure In vivo Physiology (medical) medicine Calcium ion uptake 030217 neurology & neurosurgery |
| Zdroj: | Journal of Applied Physiology. 128:241-251 |
| ISSN: | 1522-1601 8750-7587 |
| DOI: | 10.1152/japplphysiol.00230.2019 |
| Popis: | We investigated sex differences in mitochondrial Ca2+ handling properties in mouse fast-twitch skeletal muscle. Changes in cytoplasmic Ca2+ concentration ([Ca2+]cyto) were measured in vivo using tibialis anterior muscles from male and female mice. The muscles were exposed to increasing concentrations of cyclopiazonic acid [CPA; sarcoplasmic reticulum (SR) Ca2+-ATPase inhibitor] (from 10 to 30 to 50 μM at 10 min intervals). Thirty minutes after treatment, [Ca2+]cyto was increased by 31.6 ± 2.0% and 13.5 ± 4.5% of initial [Ca2+]cyto in male and female muscles, respectively, and there was a significant difference between sexes. However, muscle preincubation for 5 min with 10 μM carbonyl cyanide-4-(trifluoromethoxy) phenylhydrazone (an inhibitor of mitochondria Ca2+ uptake) eradicated this difference between sexes with respect to the CPA-induced [Ca2+]cyto increase. Both intermyofibrillar mitochondrial number and volume, assessed in longitudinal fiber sections, were higher in females compared with males (mitochondria number: 13.1 ± 1.0 in males vs. 19.9 ± 2.3 in females; mitochondrial volume: 0.034 ± 0.004 μm3/μm3 fiber volume in males vs. 0.066 ± 0.008 μm3/μm3 fiber volume in females, both P < 0.05). There were no sex differences in the content of SR Ca2+-ATPase, mitochondrial Ca2+ uniporter, mitofusin (Mfn) 1, or Mfn2. These results suggest that 1) mitochondrial Ca2+ uptake ability is greater in female than male myocytes, and 2) this superior Ca2+ uptake ability of female myocytes is due, partly, to the higher intermyofibrillar mitochondrial content but not to the expression of mitochondrial proteins related to mitochondrial Ca2+ uptake. NEW & NOTEWORTHY This investigation presents evidence that female versus male fast-twitch muscle exhibits a greater mitochondrial calcium ion uptake capability that is partly conferred by the higher intermyofibrillar mitochondrial volume density. |
| Databáze: | OpenAIRE |
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