Goger M J, Login I S, Fernandez E J, Grisham C M
Department of Chemistry, University of Virginia, Charlottesville 22901.
Magn Reson Med. 1994 Nov;32(5):584-91. doi: 10.1002/mrm.1910320507.
The MMQ cell line is a unique prolactin-secreting rat pituitary cell line. MMQ cells entrapped in agarose gel threads are metabolically active, as determined by the uptake and phosphorylation of creatine and the maintenance of high energy phosphates for over 15 h. Forskolin activates the catalytic subunit of adenylyl cyclase and, in MMQ cells, elevates the level of cAMP and stimulates prolactin secretion. 31P NMR spectroscopy was used to investigate the energy metabolism of the MMQ cells during stimulation by forskolin. The ability to measure small changes in the energy status of these cells was enhanced by increasing the PCr levels in the cells. Administration of forskolin to the perifused MMQ cells resulted in acute, reversible, and dose-dependent changes in the 31P NMR spectra of the cells within 12 to 24 min of the beginning of forskolin exposure. Several lines of evidence indicate that the changes observed in the MMQ cells are the composite result of the interaction of forskolin with adenylyl cyclase and the plasma membrane glucose transporter. Also, preincubation of the MMQ cells with the dopamine agonist, bromocriptine, attenuates the forskolin-stimulated decrease in the PCr resonance by approximately 50%. This attenuation indicates that the forskolin-stimulated changes in energy metabolism are probably related to the prolactin secretion process.
MMQ细胞系是一种独特的分泌催乳素的大鼠垂体细胞系。包裹在琼脂糖凝胶丝中的MMQ细胞具有代谢活性，这可通过肌酸的摄取和磷酸化以及高能磷酸盐维持超过15小时来确定。福司可林激活腺苷酸环化酶的催化亚基，在MMQ细胞中，可提高cAMP水平并刺激催乳素分泌。采用31P核磁共振波谱法研究福司可林刺激下MMQ细胞的能量代谢。通过提高细胞中的磷酸肌酸（PCr）水平，增强了测量这些细胞能量状态微小变化的能力。向灌注的MMQ细胞施用福司可林，在福司可林暴露开始后的12至24分钟内，细胞的31P核磁共振波谱发生急性、可逆且剂量依赖性的变化。几条证据表明，在MMQ细胞中观察到的变化是福司可林与腺苷酸环化酶和质膜葡萄糖转运体相互作用的综合结果。此外，用多巴胺激动剂溴隐亭对MMQ细胞进行预孵育，可使福司可林刺激引起的PCr共振降低约50%。这种减弱表明，福司可林刺激引起的能量代谢变化可能与催乳素分泌过程有关。
