[Protection from anoxic myocardial injury in fetal mouse heart culture by selenium]

Fetal hearts taken from the 17 day pregnant mice were cultured in minimum essential medium (MEM) + 0.5 ug ml of Na2SeO, and in MEM alone with oxygen for 24 h, and then the hearts in groups were exposed to 15, 20, 30, 40 min, 1 h, 3h and long term of anoxia respectively. The results showed that the survival and beating of the cultured fetal mouse hearts with anoxia were prolonged by selenium. Using lanthanum as a marker, we found that after 20 min of anoxia, this electroopaque marker remained extracellular in the selenium-treated hearts, however, intracellular lanthanum could be found in the control hearts, entering selectively into the swelling mitochondria. During the same period of anoxia, ACPase reaction products could be only found in the lysosomes and in the Golgi complex in the selenium-treated hearts, but a lot of reaction products deposited in cytoplasm in the control hearts. By electron microscopy, at 40 min of anoxia, there were swelling of mitochondria, with cristae partially lost and plasma-membrane changed and so on. Generally normal ultrastructure was observed in the selenium-treated hearts at 40 min of anoxia. The cytoplasm was rich in ribosomes and the sarcoplasmic reticulum with a rough face. There events showed that cellular membrane and membrane-bound organelles appeared to be well protected target by the selenium. Therefore, selenium may play an important role in the synthesis of protein.