非损伤微测技术——在细胞凋亡领域的应用

“非损伤微测技术”是在不接触被测样品的情况下长时间实时获得进出样品的特异分子/离子的流速和运动方向的信息的电生理技术。

细胞启动程序性死亡时会激活钾离子通道，利用“非损伤微测技术”，能检测卵母细胞和晶胚外的钾离子浓度变化规律，代谢氧消耗；观察不同健康状况的胚胎之间的差异。

这两个不同领域的过程调节细胞的死亡，通过研究它们的机理，可以为解决早产，细胞调亡和衰老等提供可行性思路。

举例：应用“非损伤微测技术”进行细胞凋亡的研究（双氧水处理前后受精卵的形态和胞外钾离子浓度的变化）。^{（BIOLOGY OF REPRODUCTION）}

FIG. 1. Cell shrinkage induced by H₂O₂. Zygotes treated with 200 Mm，H₂O₂ underwent shrinkage during the first 40 min of exposure.

A) Images of a shrinking zygote taken at various times before (22 min) and after (1n min) treatment with H₂O₂ (treatment at 0 min).

B) Shrinkage of zygotes coincided with H₂O₂ treatment. Embryos began to shrink immediately upon H₂O₂ treatment (filled symbols) whereas exposure of embryos to the imaging conditions did not evoke shrinkage until H₂O₂ was added (open circles). Data were gathered from images obtained at an equatorial focal plane and presented as the cross-sectional area of zygotes relative to their original cross-sectional area in the first image (100%). Each line and associated symbols represents an individual zygote.

FIG. 2. Hydrogen peroxide induces shrinkage and potassium efflux from mouse zygotes.

A) Treatment of zygotes with 200 mM H₂O₂ evoked cell shrinkage (dotted lines) and an increase in the potassium concentration of the media near embryos (solid lines). Potassium concentration data are presented as the increase in the potassium concentration of the media near embryos above that of the bulk media (2.5 mM 5 0). In each case, the middle line represents the interpolated mean value at a time relative to that of H₂O₂ application (0 min), while the outer two lines represent the interpolated standard error of the mean from the 21 embryos tested. Cell shrinkage data were gathered from images obtained at an equatorial focal plane and presented as the mean cross-sectional area of zygotes relative to their original cross-sectional area in the first image (100%). At its peak, the potassium concentration near embryos was approximately 1.5 mM above that of the bulk media and coincided with a rapid rate of cell shrinkage.

B) The gradient of potassium concentration around H₂O₂- treated zygotes decreased with increasing distance from the embryo at a rate of 1/r², where r is the distance from the center of the cell to the probe tip. The line fits the equation 1/r² for these distances. Measurements were taken at various distances from the surface of four H₂O₂-treated zygotes and suggest that H₂O₂ induced potassium efflux across the zygote plasma membrane. Error bars represent the standard deviation in the measurement at a particular distance from the center of an individual embryo.

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