Seiden D
Anat Rec. 1979 Aug;194(4):587-602. doi: 10.1002/ar.1091940411.
The specific granules found in the atrial cardiac muscle cells of the normal rat were studied. The ultrastructural appearance of these granules demonstrated a fixative-dependent lability. Fixation with cacodylate buffered aldehydes yields three types of granules. However, fixation with phosphate buffered aldehydes or primary fixation with OsO4 yields granules of uniform appearance. The granules are found predominantly in the perinuclear zone; 78% of the granules are within ten linear micrometers of the center of the nucleus. Two independent methods of measurement demonstrate spherical diameters of these granules of 0.30 micron and 0.37 micron respectively. The granules are found in greater concentration at one pole of the nucleus than at the other. On the high density side there are 4.07 granules/micrometers3 which occupy 5.8% of the cytoplasmic volume. On the low density side there are 2.15 granules/micrometers3 which occupy 3.0% of the cytoplasmic volume. The granules at both poles are the same size. Atrial walls were incubated in a modified Tyrode's solution. One hour of incubation caused no change in the atrial granules. Addition of norepinephrine or L-Dopa resulted in the appearance of more granules but the size of the granules remained the same. Incubation with reserpine had no effect upon the atrial granules. Apparently the atrial myocardial cell is stimulated by exogenous catecholamine to synthesize more atrial granules which themselves do not appear to contain catecholamines.
对正常大鼠心房心肌细胞中发现的特异性颗粒进行了研究。这些颗粒的超微结构外观显示出对固定剂的依赖性不稳定性。用二甲胂酸盐缓冲醛固定产生三种类型的颗粒。然而，用磷酸盐缓冲醛固定或先用四氧化锇固定则产生外观均匀的颗粒。颗粒主要存在于核周区；78%的颗粒位于距细胞核中心10线性微米范围内。两种独立的测量方法分别显示这些颗粒的球形直径为0.30微米和0.37微米。在细胞核的一极发现的颗粒浓度比另一极更高。在高密度一侧，每立方微米有4.07个颗粒，占细胞质体积的5.8%。在低密度一侧，每立方微米有2.15个颗粒，占细胞质体积的3.0%。两极的颗粒大小相同。将心房壁在改良的台氏液中孵育。孵育1小时后心房颗粒无变化。加入去甲肾上腺素或左旋多巴会导致出现更多颗粒，但颗粒大小保持不变。用利血平孵育对心房颗粒没有影响。显然，外源性儿茶酚胺刺激心房心肌细胞合成更多的心房颗粒，而这些颗粒本身似乎不含儿茶酚胺。
