Hiram Y, Nir A, Zinder O
Biophys J. 1982 Jul;39(1):65-9. doi: 10.1016/S0006-3495(82)84491-3.
Catecholamine release from chromaffin granules, suspended in sucrose solutions of various osmotic strengths, was determined at different temperatures between 2 degrees and 44 degrees C. Dynamic measurements showed that steady state is achieved within 15 min of incubation at all temperatures. The effect of temperature on the release was established in terms of the median granular fragility (MGF) defined as the concentration of sucrose solution causing 50% lysis. The MGF was determined as the inflection point of the Gaussian distribution of granular fragility. The MGF was found to decrease with fall in temperature implying a corresponding increase of the tensile strength of the vesicle membrane. Critical resultant forces at lysis were calculated and found to vary from 8.2 dyn/cm at 2 degrees C to 4.2 dyn/cm at 44 degrees C. These compare well with tensions at lysis found earlier for erythrocytes.
测定了悬浮于不同渗透压强度蔗糖溶液中的嗜铬颗粒在2℃至44℃不同温度下的儿茶酚胺释放情况。动态测量表明，在所有温度下孵育15分钟内均可达到稳态。根据定义为导致50%裂解的蔗糖溶液浓度的中位颗粒脆性（MGF）来确定温度对释放的影响。MGF被确定为颗粒脆性高斯分布的拐点。发现MGF随温度降低而降低，这意味着囊泡膜的抗张强度相应增加。计算了裂解时的临界合力，发现其范围从2℃时的8.2达因/厘米到44℃时的4.2达因/厘米。这些结果与早期发现的红细胞裂解时的张力相当吻合。
