Muscle interstitial calcium during head-up tilt in humans

Article

关键词: VASCULAR SMOOTH-MUSCLE;    RABBIT PORTAL-VEIN;    SENSING RECEPTOR;    ALPHA(5)BETA(1) INTEGRIN;    TRANSMITTER RELEASE;    NERVE-TERMINALS;    CATION CHANNELS;    CELLS;    CLONING;    SYNCOPE;   

DOI  :  10.1161/01.CIR.0000108394.43429.A9

来源: SCIE

【 摘 要 】

Background - During head-up tilt ( HUT), peripheral vasoconstriction occurs. This response requires appropriate communication between the sympathetic nerve terminal and vascular smooth muscle cell in the neurovascular space. Both of these cell types require extracellular calcium ([Ca2+](o)) for proper activation and function. We hypothesize that [Ca2+](o) rises with tilt and in the process contributes to vasoconstriction. Methods and Results - We used microdialysis techniques in the lower-limb skeletal muscle to measure [Ca2+](o) changes in this space with HUT. [Ca2+](o) was measured in 10 healthy subjects during HUT. We found a 62% increase in the dialysate [Ca2+] (0.223 +/- 0.018 to 0.353 +/- 0.028 mmol/L) with HUT. Conclusions - This result implies a significant increase in [Ca2+](o) in the neurovascular space during HUT. This represents the first report of such in situ [Ca2+](o) measurements in humans. This rise in [Ca2+](o) may provide a mechanism for proper cell-cell interaction, helping to promote peripheral vasoconstriction during HUT. How this [Ca2+](o) transient affects the nerve terminal, vascular smooth muscle cells, or both remains to be determined.

【 授权许可】

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