Hazel J R, Schuster V L
J Exp Zool. 1976 Mar;195(3):425-38. doi: 10.1002/jez.1401950309.
Thermal acclimation of rainbow trout (Salmo gairdneri) taken from 20 degrees C to 7 degrees C resulted in adaptation of mitochondrial function, as evidenced by increases in the specific activities of NADH- and succinate-cytochrome c reductase of 1.93- and 2.7-fold respectively. Mitochondria from both gill and liver obeyed the Boyle-van't Hoff relationship in the range from 400 to 60 mosM. Thermal acclimation had no effect on the osmotic properties of liver mitochondria, whereas gill mitochondria from cold-acclimated trout were more sensitive to osmotic swelling than mitochondria from warm-acclimated individuals. The non-electrolyte permeability of liver mitochondria was assessed by optically monitoring mitochondrial swelling rates in isosmotic solutions of urea, glycerol, mannitol and glucose. Two parameters of mitochondrial swelling were determined: (a) initial swelling rates, d(1/A)dt, and (b) swelling constants, ks, derived from the time required to swell a fixed volume. Regardless of the assay temperature or the permeant employed, liver mitochondria from cold-acclimated trout exhibited greater initial swelling rates than mitochondria from warm-acclimated trout, indicating properties of temperature-compensated permeability. The apparent ranking of nonelectrolyte permeabilities was urea greater than glycerol greater than mannitol greater than glucose. ks values for urea and glycerol from cold-acclimated trout were greater than values typical of warm-acclimated populations; however ks values for glucose and mannitol were not influenced by thermal acclimation. Regardless of the permeant considered, activation energies for ks values were 3- to 5-fold greater than those for initial swelling rates. The time course of mitochondrial swelling consists of two components, an initial rapid swelling phase characterized by a half-life of 3-12 seconds, and a slower swelling phase characterized by a half life of 1-6 minutes. Initial swelling rates, which approximate the rapid swelling component, are considered to be the least ambiguous index of permeability, whereas ks values are more complex and strongly influenced by the slower swelling component.
将虹鳟（Salmo gairdneri）从20℃转移至7℃进行热驯化，结果显示其线粒体功能发生了适应性变化，这表现为NADH - 细胞色素c还原酶和琥珀酸 - 细胞色素c还原酶的比活性分别增加了1.93倍和2.7倍。鳃和肝脏中的线粒体在400至60 mosM范围内均符合玻意耳 - 范特霍夫关系。热驯化对肝脏线粒体的渗透特性没有影响，而冷驯化虹鳟的鳃线粒体比热驯化个体的线粒体对渗透性肿胀更敏感。通过光学监测线粒体在尿素、甘油、甘露醇和葡萄糖等渗溶液中的肿胀速率来评估肝脏线粒体的非电解质通透性。确定了线粒体肿胀的两个参数：（a）初始肿胀速率，d(1/A)dt，以及（b）肿胀常数ks，它由固定体积肿胀所需的时间得出。无论测定温度或所用渗透剂如何，冷驯化虹鳟的肝脏线粒体比热驯化虹鳟的线粒体表现出更高的初始肿胀速率，这表明其具有温度补偿通透性的特性。非电解质通透性的明显排序为尿素＞甘油＞甘露醇＞葡萄糖。冷驯化虹鳟的尿素和甘油的ks值大于热驯化群体的典型值；然而，葡萄糖和甘露醇的ks值不受热驯化的影响。无论考虑哪种渗透剂，ks值的活化能比初始肿胀速率的活化能大3至5倍。线粒体肿胀的时间进程由两个部分组成，一个初始快速肿胀阶段，其半衰期为3至12秒，另一个较慢的肿胀阶段，其半衰期为1至6分钟。初始肿胀速率近似于快速肿胀部分，被认为是通透性最明确的指标，而ks值更复杂且受较慢肿胀部分的强烈影响。
