目的:观测研究下坡(离心)运动对大鼠骨骼肌肌浆网Ca2+-ATP酶活性,Ca2+摄取与释放在量与时程上的影响。此外,测定离子载体的刺激作用,即测定在含与不含(Ca2+离子载体)A23187时Ca2+-ATP酶活性的比值,用以评定囊泡的完整性。方法:成年雄性S...目的:观测研究下坡(离心)运动对大鼠骨骼肌肌浆网Ca2+-ATP酶活性,Ca2+摄取与释放在量与时程上的影响。此外,测定离子载体的刺激作用,即测定在含与不含(Ca2+离子载体)A23187时Ca2+-ATP酶活性的比值,用以评定囊泡的完整性。方法:成年雄性SD大鼠随机分为对照与离心运动组,离心运动的大鼠分别于运动后即刻,4,24,48,72和144h后取样(n=7).离心运动方式采用90min持续跑台下坡运动(-16°;15m/min)。取大鼠红股肌制备组织匀浆,测定肌浆网Ca2+-ATP酶活性,Ca2+摄取与释放。结果:与对照组[19.25±1.38nmol·min-1·(mg protein)-1]相比,肌浆网Ca2+摄取分别于运动后即刻和4h下降了29% and 36%(P<0.05),24h依然降低(P<0.05).肌浆网Ca2+释放与对照组[31.06±2.36nmol·min-1·(mg protein)-1]相比,也分别于运动后即刻和4h下降了37% and 39%(P<0.05),24h持续降低(P<0.05).用含离子载体测定的肌浆网Ca2+-ATP酶活性运动后4h降低了31%(P<0.05),并于运动后24h仍然降低(P<0.05)。运动后,含与不含A23187时测定的Ca2+-ATP酶活性的比值未见显著性改变,表明该运动没有明显改变肌浆网膜的完整性。结论:一次性低强度,长时间下坡运动导致肌浆网功能长时间降低,运动后恢复期两天尚未完全恢复,亦可构成离心运动诱导的骨骼肌某些功能降低的基础。提示这些变化可能产生于离心收缩时肌节长度不匀一性所造成的张力应激。展开更多
Plant mineral nutrition is essential for crop yields and human health.However,the uneven distribution of mineral elements over time and space leads to a lack or excess of available mineral elements in plants.Among the...Plant mineral nutrition is essential for crop yields and human health.However,the uneven distribution of mineral elements over time and space leads to a lack or excess of available mineral elements in plants.Among the essential nutrients,calcium(Ca^(2+))stands out as a prominent second messenger that plays crucial roles in response to extracellular stimuli in all eukaryotes.Distinct Ca^(2+)signatures with unique parameters are induced by different stresses and deciphered by various Ca^(2+)sensors.Recent research on the participation of Ca^(2+)signaling in regulation of mineral elements has made great progress.In this review,we focus on the impact of Ca^(2+)signaling on plant mineral uptake and detoxification.Specifically,we emphasize the significance of Ca^(2+)signaling for regulation of plant mineral nutrition and delve into key points and novel avenues for future investigations,aiming to offer new insights into plant ion homeostasis.展开更多
文摘目的:观测研究下坡(离心)运动对大鼠骨骼肌肌浆网Ca2+-ATP酶活性,Ca2+摄取与释放在量与时程上的影响。此外,测定离子载体的刺激作用,即测定在含与不含(Ca2+离子载体)A23187时Ca2+-ATP酶活性的比值,用以评定囊泡的完整性。方法:成年雄性SD大鼠随机分为对照与离心运动组,离心运动的大鼠分别于运动后即刻,4,24,48,72和144h后取样(n=7).离心运动方式采用90min持续跑台下坡运动(-16°;15m/min)。取大鼠红股肌制备组织匀浆,测定肌浆网Ca2+-ATP酶活性,Ca2+摄取与释放。结果:与对照组[19.25±1.38nmol·min-1·(mg protein)-1]相比,肌浆网Ca2+摄取分别于运动后即刻和4h下降了29% and 36%(P<0.05),24h依然降低(P<0.05).肌浆网Ca2+释放与对照组[31.06±2.36nmol·min-1·(mg protein)-1]相比,也分别于运动后即刻和4h下降了37% and 39%(P<0.05),24h持续降低(P<0.05).用含离子载体测定的肌浆网Ca2+-ATP酶活性运动后4h降低了31%(P<0.05),并于运动后24h仍然降低(P<0.05)。运动后,含与不含A23187时测定的Ca2+-ATP酶活性的比值未见显著性改变,表明该运动没有明显改变肌浆网膜的完整性。结论:一次性低强度,长时间下坡运动导致肌浆网功能长时间降低,运动后恢复期两天尚未完全恢复,亦可构成离心运动诱导的骨骼肌某些功能降低的基础。提示这些变化可能产生于离心收缩时肌节长度不匀一性所造成的张力应激。
基金supported by the National Natural Science Foundation of China(32222008 to C.W.)the China Postdoctoral Science Foundation(2023M732883 to C.J.).
文摘Plant mineral nutrition is essential for crop yields and human health.However,the uneven distribution of mineral elements over time and space leads to a lack or excess of available mineral elements in plants.Among the essential nutrients,calcium(Ca^(2+))stands out as a prominent second messenger that plays crucial roles in response to extracellular stimuli in all eukaryotes.Distinct Ca^(2+)signatures with unique parameters are induced by different stresses and deciphered by various Ca^(2+)sensors.Recent research on the participation of Ca^(2+)signaling in regulation of mineral elements has made great progress.In this review,we focus on the impact of Ca^(2+)signaling on plant mineral uptake and detoxification.Specifically,we emphasize the significance of Ca^(2+)signaling for regulation of plant mineral nutrition and delve into key points and novel avenues for future investigations,aiming to offer new insights into plant ion homeostasis.
