The expression ofLdh-cin the skeletal muscle of plateau pika (Ochotona curzoniae) enhances adaptation to a hypoxic environment

Abstract

The plateau pika (Ochotona curzoniae) is a species of sprint-running alpine animals in the Qinghai-Tibet Plateau, which is a harsh highland hypoxic environment. Ldh-c is expressed in the testis, sperm and somatic tissues of plateau pika. To reveal the role and physiological mechanisms of sperm-specific lactate dehydrogenase (LDH-C4), in plateau pika to adapt to hypoxic environment, an adenoviral line of pMultiRNAi-Ldhc was constructed and injected into the bilateral biceps femoris of the hind legs. The swimming times of the pikas, and the Ldh-c expression levels, total LDH activities and ATP levels in skeletal muscle, were measured after the pikas were raised in the trapped site for 5 days. Our results showed that after Ldh-c was silenced, the sprint-running ability (swimming time) of the plateau pikas was significant decreased, and the total LDH activities and ATP levels were reduced by 28.21% and 27.88%, respectively. Our results indicated that expression of Ldh-c in the skeletal muscle of plateau pika increased anaerobic glycolysis and enhanced adaptation to highland hypoxic environments.

The hypoxia adaptation of small mammals to plateau and underground burrow conditions

“…94 In addition, the expression of lactate-dehydrogenase-C in the skeletal muscle of plateau pikas (Ochotona curzoniae) increases their anaerobic glycolytic capacity, reduces the animals' dependence on O 2 , 98 and enhances their adaptation to the hypoxic environment of the plateau. 99 One of the biggest challenges faced by mammals in underground tunnels is the high energy cost of excavation in order to find limited food resources underground and maintain cave structures. 100,101 For example, NMRs, as is typical of the hypoxia-tolerant subterranean rats, have a basal metabolic rate that is about 30% lower than that of similarly sized mammals.…”

“…These adaptations may account for the maintenance of adequate energy supply to skeletal muscle tissue in Qinghai voles under hypoxic stress 94 . In addition, the expression of lactate‐dehydrogenase‐C in the skeletal muscle of plateau pikas ( Ochotona curzoniae ) increases their anaerobic glycolytic capacity, reduces the animals' dependence on O 2 , 98 and enhances their adaptation to the hypoxic environment of the plateau 99 …”