Brustovetskiĭ N N, Amerkhanov Z G, Grishina E V, Maevskiĭ E I
Biokhimiia. 1990 Feb;55(2):201-9.
The rate of respiration and ATP synthesis in liver mitochondria (M) isolated from hibernating ground squirrels and incubated in the medium with normal tonicity (250 mosm) was shown to be considerably lower than the rate of respiration and ATP synthesis in liver M from active animals. The increase of the medium tonicity to 600 mosm simulated the state of M from hibernating animals, resulting in a decrease of the respiration rate of M from active ground squirrels. On the contrary, the decrease of the tonicity to 60 mosm caused the activation of the respiration and increase of the ATP synthesis in M from hibernating ground squirrels. Bromophenacylbromide (BPhB), an inhibitor of phospholipase A2, prevented the activation of the respiration of M from hibernating animals incubated in the medium with low tonicity. BPhB had practically no effect on the respiration of M from both hibernating and active ground squirrels as well as on the swelling of M in hypotonic medium. It was concluded that the activation of the respiration and increase of the ATP synthesis rate in M from hibernating ground squirrels incubated in the medium with low tonicity is related to the activation of phospholipase A2. It was assumed that decrease of phospholipase A2 activity and change in the lipid composition of mitochondrial membrane may be one of the reasons for inhibition of the respiration rate in M from hibernating ground squirrels.
从冬眠地松鼠分离出的肝线粒体（M），在等渗（250毫渗量）培养基中孵育时，其呼吸速率和ATP合成速率显著低于活动状态动物的肝线粒体。将培养基渗透压提高到600毫渗量可模拟冬眠动物线粒体的状态，导致活动状态地松鼠的线粒体呼吸速率降低。相反，将渗透压降低到60毫渗量会使冬眠地松鼠的线粒体呼吸激活，ATP合成增加。磷脂酶A2抑制剂溴苯甲酰溴（BPhB）可阻止在低渗培养基中孵育的冬眠动物线粒体呼吸的激活。BPhB对冬眠和活动状态地松鼠的线粒体呼吸以及线粒体在低渗培养基中的肿胀几乎没有影响。得出的结论是，在低渗培养基中孵育的冬眠地松鼠的线粒体呼吸激活和ATP合成速率增加与磷脂酶A2的激活有关。据推测，磷脂酶A2活性降低和线粒体膜脂质组成的变化可能是冬眠地松鼠线粒体呼吸速率受抑制的原因之一。
