Santer R M, Hann A C
Department of Anatomy, University of Wales College of Cardiff, UK.
Histochemistry. 1993 Jan;99(1):43-8. doi: 10.1007/BF00268019.
X-ray microanalysis has been used to detect chromium in the histochemical reaction product resulting from the reaction of noradrenaline with glutaraldehyde during fixation of the rat adrenal medulla and subsequent treatment with potassium dichromate. In unstained ultrathin sections, noradrenaline cells can be identified by their content of highly electron-dense storage granules, which enables individual granules to be analysed quantitatively to assess the amount of bound chromium within them. In young adult (4-month-old) rats the mean chromium content of noradrenaline-containing adrenal medullary granules was 443.6 +/- 50.7 mM/kg dry weight. In aged (24-month-old) animals the mean chromium content was 267.0 +/- 64.0 mM/kg dry weight which was significantly (P < 0.01) lower then the value for the young adult rats. Some noradrenaline cells contained granule populations, which were markedly less electron dense than those in the young adults and this is reflected in the ranges of chromium values recorded between individual cells in the 24-month-old animals. There were also noradrenaline cells in the medulla of the aged animals, which contained highly electron-dense granules but these did not contain as much bound chromium as the highest values recorded in the young adult animals. The results are discussed in the context of the growth of the rat adrenal medulla throughout the lifespan and with respect to the effects of age on the integrity of storage granules.
在大鼠肾上腺髓质固定过程中，去甲肾上腺素与戊二醛反应，随后用重铬酸钾处理，利用X射线微量分析检测组织化学反应产物中的铬。在未染色的超薄切片中，去甲肾上腺素细胞可通过其富含高电子密度储存颗粒来识别，这使得能够对单个颗粒进行定量分析，以评估其中结合的铬含量。在成年（4个月大）大鼠中，含去甲肾上腺素的肾上腺髓质颗粒的平均铬含量为443.6±50.7 mM/千克干重。在老年（24个月大）动物中，平均铬含量为267.0±64.0 mM/千克干重，显著低于成年大鼠的值（P<0.01）。一些去甲肾上腺素细胞含有颗粒群，其电子密度明显低于成年大鼠，这反映在24个月大动物单个细胞之间记录的铬值范围内。老年动物的髓质中也有去甲肾上腺素细胞，其含有高电子密度颗粒，但这些颗粒所含的结合铬不如成年动物中记录的最高值多。结合大鼠肾上腺髓质在整个生命周期中的生长情况以及年龄对储存颗粒完整性的影响对结果进行了讨论。
