THE INFLUENCE OF INTRACELLULAR CALCIUM-CONCENTRATION ON DE-GRANULATION OF DIALYZED MAST-CELLS FROM RAT PERITONEUM
THE INFLUENCE OF INTRACELLULAR CALCIUM-CONCENTRATION ON DE-GRANULATION OF DIALYZED MAST-CELLS FROM RAT PERITONEUM
复制标题
DOI：
10.1113/jphysiol.1988.sp016914
复制
发表时间：
1988-01-01
影响因子：
5.5
通讯作者：
NEHER, E
中科院分区：
文献类型：
--
作者：
NEHER, E
1.肥大细胞，从大鼠腹膜分离，研究下密封，全细胞记录条件。同时测量膜电导、膜电容和细胞内游离Ca 2+浓度[Ca 2 +]i。2. [Ca2只有当相对高浓度的钙缓冲液（在毫摩尔范围内）被加入到细胞质被透析的吸移管填充溶液中时，+]i才能被精确地缓冲到0和1.5 μ M之间的值。在较低的缓冲液浓度[Ca 2 +]i显着增加超极化的膜。3.当加入到移液管中时，鸟苷-3-硫代-三磷酸（GTP-γ- S），三磷酸鸟苷的不可水解类似物，刺激膜电容增加3.3倍，这表明肥大细胞脱粒（费尔南德斯，Neher和Gomperts，1984）。4.在弱缓冲细胞中，GTP-γ- S也引起了短暂的增加[Ca 2 +]i，通常，脱粒之前。1-5 mM浓度的钙缓冲液抑制了这种瞬变。5.高[Ca 2 +]i单独不诱导脱粒。然而，它显著地加速了GTP-γ- S诱导的脱粒。当[Ca 2 +]i被缓冲至零时，响应于GTP-γ-ATP，细胞的可感知部分脱颗粒。S，但非常缓慢，只有经过一个长时间的滞后阶段。6. [Ca 2 +]i的瞬时增加，由GTP-γ- S或电压变化，在滞后期期间不引起电容变化，但加速了GTP-γ的增加。S诱导的脱粒反应在稍后的时间。7.内部施用的1，4，5-三磷酸肌醇（IP 3）也诱导[Ca 2 +]i的瞬时增加，这在不存在GTP-γ时不导致分泌。S. 8.它的结论是，增加[Ca 2 +]i是既不必要，也不足以从透析肥大细胞分泌。[Ca2然而，[+]I与其它刺激物协同作用以促进分泌。它是更有效的时间越多的其他刺激已被允许启动细胞。
1. Mast cells, isolated from rat peritoneum, were studied under tight-seal, whole-cell recording conditions. Membrane conductance, membrane capacitance and the concentration of free intracellular Ca2+, [Ca2+]i, were measured simultaneously. 2. [Ca2+]i could be accurately buffered to values between 0 and 1.5 .mu.M only if relatively high concentrations of calcium buffers (in the millimolar range) were added to the pipette filling solution against which the cytoplasm was dialyzed. At lower buffer concentrations [Ca2+]i was markedly increased by hyperpolarizing the membrane. 3. When added to the pipette, guanosine-3-thio-triphosphate (GTP-.gamma.-S), a non-hydrolyzable analogue of guanosine triphosphate, stimulated a 3.3-fold increase in membrane capacitance, which is indicative of mast cell degranulation (Fernandez, Neher and Gomperts, 1984). 4. In weakly buffered cells, GTP-.gamma.-S also induced a transient increase in [Ca2+]i which, usually, preceded degranulation. Calcium buffers at 1-5 mM concentration suppressed this transient. 5. High [Ca2+]i alone did not induce degranulation. However, it markedly accelerated GTP-.gamma.-S-induced degranulation. When [Ca2+]i was buffered to zero, an appreciable fraction of cells degranulated in response to GTP-.gamma.-S, but very slowly, and only after a long lag phase. 6. Transient increases in [Ca2+]i, evoked either by GTP-.gamma.-S, or by voltage changes, did not elicit capacitance changes during the lag phase, but accelerated the GTP-.gamma.-S-induced degranulation response at later times. 7. Internally applied inositol 1,4,5-trisphosphate (IP3) also induced transient increases in [Ca2+]i which did not lead to secretion in the absence of GTP-.gamma.-S. 8. It is concluded that an increase in [Ca2+]i is neither necessary nor sufficient for secretion from dialyzed mast cells. [Ca2+]i, however, acts synergistically with other stimuli to promote secretion. It is the more efficient the more time the other stimulus had been allowed for priming the cell.