[Ultrastructural studies of mitochondria in striated muscles of birds with reference to experimental hypokinesis]

Electron microscopic studies have been carried out on the mitochondria of the transversely striated muscles with regard to experimental hypokinasis. As compared to the control group the mitochondria of m. pectoralis thoracicus and the m. iliotibialis posterior in hypokinetic birds reveal marked changes. In filamentous and ovoid mitochondria vacuoles can be observed which in some cases produced larger light formations with following disappearance of the cristae and destruction of mitochondria. Fat particles located at the poles of the altered mitochondria, sporadically occurring also laterally, presented another finding. The Z-lines of the sarcomer did not form a continuous line, but were somewhat shifted.