title: [Changes in the muscle ultrastructure and electrolyte composition of rats in embryogenesis. II. X-ray spectrum microanalysis of the intracellular concentrations of potassium, sodium and phosphorus in skeletal and heart muscle].
abstract: Concentrations of K, P and Na were determined in skeletal and cardiac muscle cells of rat embryos. High K and P levels--133 and 166 mmole/kg wet weight, resp.,--were found in skeletal muscles of 13 day old embryos, the concentration of Na in these cells being 81 mmole/kg w. w. On the 18th day of development, K and P in skeletal muscle cells decreased down to 79 and 118 mmole/kg w. w., resp., while the concentration of Na increased to 165 mmole/kg w. w. In 19 day old embryos, the concentrations of K and P increased, although they did not reach the level typical of skeletal muscles of adult rats. The concentrations of K and P in cardiac muscle cells of 13 day embryos were found equal to 100 and 108 mmole/kg w. w., resp., on the 19th day of development these concentrations reached the level typical of the cardiac muscle cells of adult rats.
mesh_terms: D000818:Animals; D004577:Electron Probe Microanalysis; D005865:Gestational Age; D006321:Heart / Q000196:embryology*; D008854:Microscopy, Electron; D009132:Muscles / Q000196:embryology / Q000378:metabolism / Q000648:ultrastructure*; D009206:Myocardium / Q000378:metabolism / Q000648:ultrastructure*; D010758:Phosphorus / Q000378:metabolism*; D011188:Potassium / Q000032:analysis*; D051381:Rats; D011919:Rats, Inbred Strains / Q000196:embryology*; D012964:Sodium / Q000378:metabolism*
chemical_list: D010758:Phosphorus; D012964:Sodium; D011188:Potassium
vernacular_title: Izmenenie ul'trastruktury i élektrolitnogo sostava myshts krys v émbriogeneze. II. Rentgenospektral'nyĭ mikroanaliz vnutrikletochnykh kontsentratsiĭ kaliia, natriia i fosfora skeltnoĭ i serdechnoĭ myshts.