Cyclic 3',5' AMP relay in Dictyostelium discoideum. I. A technique to monitor responses to controlled stimuli
Cyclic 3',5' AMP relay in Dictyostelium discoideum. I. A technique to monitor responses to controlled stimuli
复制标题
盘基网柄菌中的环状 3,5 AMP 中继。
DOI：
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发表时间：
1979
影响因子：
7.8
通讯作者：
Theodore L. Steck
中科院分区：
文献类型：
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作者：
P. N. Devreotes;Pamela L. Derstine;Theodore L. Steck
开发了一种灌注技术，以向氚标记的盘状网柄藻（Dictyosteelium discoideum amoeulum）递送明确定义的幅度和持续时间的[14 C]腺苷3 '，5'-环一磷酸（cAMP）刺激，并同时监测[3 H]cAMP（即，中继响应）。响应于[14 C]cAMP刺激而分泌的氚化化合物在[3 H]cAMP中高度富集，并且反映了伴随刺激的细胞内cAMP的增加，而不是预先存在的储存或大量细胞内容物的释放。在分化过程中，对2分钟刺激的分泌反应（每10（6）个细胞）从0.5小时的约0.2 pmol cAMP增加到7小时的约5 pmol cAMP。没有足够的灌注，阿米巴改变了cAMP的水平在其环境中的两种方式：磷酸二酯酶破坏cAMP刺激在某些条件下，以减弱中继反应;在其他情况下，分泌的cAMP放大最小的外源性刺激到最大的反应。此外，如果环磷酸腺苷的清除或破坏被中断，阿米巴会对它们的基础分泌产生自催化作用。灌注系统使这些细胞诱导的修饰最小化，从而允许在定量研究中控制刺激和反应的水平。
A perfusion technique was developed to deliver [14C]adenosine 3',5'- cyclic monophosphate (cAMP) stimuli of well-defined magnitude and duration to tritium-labeled Dictyostelium discoideum amoebae and simultaneously monitor the elicited secretion of [3H]cAMP (i.e., the relay response). The tritiated compounds secreted in response to [14C]cAMP stimuli were highly enriched in [3H]cAMP and reflected an increase in intracellular cAMP accompanying stimulation rather than the release of a preexisting store or bulk cellular contents. The secretory response (per 10(6) cells) to 2-min stimuli increased during differentiation from about 0.2 pmol at 0.5 h to approximately 5 pmol of cAMP at 7 h. Without adequate perfusion, amoebae altered the level of cAMP in their environment in two ways: phosphodiesterases destroyed cAMP stimuli under some conditions so as to attenuate the relay response; under other circumstances, secreted cAMP magnified minimal exogenous stimuli into maximal responses. Amoebae, furthermore, would respond to their basal secretion of cAMP autocatalytically if its removal or destruction were interrupted. The perfusion system minimized these cell-induced modifications, allowing control of the level of the stimulus and response in quantitative studies.