Microcirculation (New York, N.Y. : 1994) · 2020
Aging alters spontaneous and neurotransmitter-mediated Ca2+ signaling in smooth muscle cells of mouse mesenteric arteries.
СтатьяПоддержка NIH: внешняя программаНазвание и аннотация: Перевод в очереди
Обработка статьи · этапы, ошибки и управление
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История · было → стало
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Boerman Erika M, Segal Steven S
Аннотация
OBJECTIVE: Aging impairs MA dilation by reducing the ability of sensory nerves to counteract sympathetic vasoconstriction. This study tested whether altered SMC Ca2+ signals to sympathetic (NE) and sensory (CGRP) neurotransmitters underlie aging-related deficits in vasodilation.
METHODS: MAs from young and old mice were pressurized and loaded with Fluo-4 dye for confocal measurement of SMC Ca2+ sparks and waves. Endothelial denudation resolved the influence of ECs. SMCs were immunolabeled for RyR isoforms and compared with transcript levels for RyRs and CGRP receptor components.
RESULTS: SMCs from young vs old mice exhibited more spontaneous Ca2+ spark sites with no difference in Ca2+ waves. NE reduced spark sites and increased waves for both groups; addition of CGRP restored sparks and reduced waves only for young mice. Endothelial denudation attenuated Ca2+ responses to CGRP for young but not old mice, which were already attenuated, suggesting a diminished role for ECs with aging. CGRP receptor expression was similar between ages with increased serum CGRP in old mice, where RyR1 expression was replaced by RyR3.
CONCLUSION: With aging, we suggest that altered RyR expression in SMCs contributes to impaired ability of sensory neurotransmission to restore Ca2+ signaling underlying vasomotor control during sympathetic activation.
METHODS: MAs from young and old mice were pressurized and loaded with Fluo-4 dye for confocal measurement of SMC Ca2+ sparks and waves. Endothelial denudation resolved the influence of ECs. SMCs were immunolabeled for RyR isoforms and compared with transcript levels for RyRs and CGRP receptor components.
RESULTS: SMCs from young vs old mice exhibited more spontaneous Ca2+ spark sites with no difference in Ca2+ waves. NE reduced spark sites and increased waves for both groups; addition of CGRP restored sparks and reduced waves only for young mice. Endothelial denudation attenuated Ca2+ responses to CGRP for young but not old mice, which were already attenuated, suggesting a diminished role for ECs with aging. CGRP receptor expression was similar between ages with increased serum CGRP in old mice, where RyR1 expression was replaced by RyR3.
CONCLUSION: With aging, we suggest that altered RyR expression in SMCs contributes to impaired ability of sensory neurotransmission to restore Ca2+ signaling underlying vasomotor control during sympathetic activation.