PANCREATIC ACINAR CELLS - EFFECTS OF LANTHANUM IONS ON AMYLASE RELEASE AND CALCIUM-ION FLUXES
PANCREATIC ACINAR CELLS - EFFECTS OF LANTHANUM IONS ON AMYLASE RELEASE AND CALCIUM-ION FLUXES
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DOI：
10.1113/jphysiol.1974.sp010779
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发表时间：
1974-01-01
影响因子：
5.5
通讯作者：
WILLIAMS, JA
中科院分区：
文献类型：
--
作者：
CHANDLER, DE;WILLIAMS, JA
1. 研究了La3+对小鼠胰腺碎片淀粉酶释放和Ca2+通量的影响。2. 0.1 mM-La3+可增加淀粉酶的释放，1.0 mm -10 mM-La3+可逐渐抑制淀粉酶的释放。未受刺激和受麻酚刺激的分泌以相同的方式改变。淀粉酶释放抑制快速且可逆。3. 45Ca2+的吸收是多相的，在2小时后仍未完全达到平衡。La3+ (10 mM)限制了45Ca2+对细胞外空间的吸收，并略微降低了总Ca2+含量。低浓度的La3+以双相方式影响45Ca2+的吸收和总Ca2+含量，并与淀粉酶释放的影响平行。4. La3+限制了45Ca2+在细胞外空间向同位素的冲洗，并消除了亚酚刺激的45Ca2+外排的增加。5. 通过“镧”方法测量的45Ca2+进入细胞内空间的摄取不受亚铁酚的影响。6. La3+对组织超微结构和Na+、K+含量没有影响。7. 因此，细胞外Ca2+的内流对触发淀粉酶分泌并不重要，La3+可能通过作用于淀粉酶的释放过程而不是Ca2+内流来抑制淀粉酶的释放。图片
1. The effect of La3+ on amylase release and Ca2+ fluxes in mouse pancreatic fragments in vitro was studied. 2. Amylase release was increased by 0·1 mM-La3+ and progressively inhibited by 1·0-10 mM-La3+. Non-stimulated and bethanecol stimulated secretion were altered in an identical manner. Inhibition of amylase release was rapid and reversible. 3. Uptake of 45Ca2+ was multiphasic with equilibrium with stable Ca2+ still not complete after 2 hr. La3+ (10 mM) limited uptake of 45Ca2+ to the extracellular space and slightly decreased total Ca2+ content. Lower concentrations of La3+ affected 45Ca2+ uptake and total Ca2+ content in a biphasic manner which paralleled effects on amylase release. 4. La3+ restricted washout of 45Ca2+ to isotope in the extracellular space and abolished the bethanecol-stimulated increase in 45Ca2+ efflux. 5. Uptake of 45Ca2+ into intracellular space, as measured by the `lanthanum' method, was not affected by bethanecol. 6. Tissue ultrastructure and Na+ and K+ content were not affected by La3+. 7. It is concluded that an influx of extracellular Ca2+ is not important for triggering of secretion and that La3+ may inhibit amylase release by acting on the release process rather than on Ca2+ influx. Images