Characteristics of LDH isoenzyme spectrum in tissues of plateau pika. There were six LDH isoenzyme bands in all tissues (Panels A and B), and the patterns in the somatic tissues were same as that in testis and sperm (Panel C). The third band from cathode to anode (indicated by an arrow) in LDH isoenzymes was heat-stable (Panel D). Panels A and B, LDH isoenzyme spectrum of male and felmale plateau pika, lanes 1–7 are heart, liver, lung, kidney, brain, skeletal muscle and testis of plateau pika, respectively. Panel C, LDH isoenzyme spectrum in plateau pika's sperm. Lanes 1–5 are brain, lung, kidney, testis and sperm of plateau pika, respectively. Panel D, thermal stability of LDH isoenzymes in plateau pika's liver. Lanes 1–3 are the homogenate of plateau pika liver frozen in liquid nitrogen, incubated at 50 °C for 40 min, and incubated at 55 °C for 55 min, respectively. From the anode (bottom of gel) to cathode is follows: LDH-B4, LDH-B3A1, LDH-B2A2, LDH-C4 (indicated by an arrow), LDH-B1A3 and LDH-A4.