Ultrastructural and cytochemical observation of calcium ion localization in the black-beetle pleural muscles.

The authors examined the infrastructure and distribution of calcium ions in the plexural muscles of a black-beetle (Blatta orientalis L.) after being fixed in a solution of osmiumtetroxide buffered with a cacodylate buffer (pH = 7.4) and according to the method of Carasso-Favard (1966). The infrastructure of these muscles differs from the muscles of other insects, first of all, in the amount and distribution of the sarcoplasmic net (SR) and mitochondria and also in the amount and topography of the location of lead precipitations which mark the calcium ions. The authors ascertained an intensive and permanent positive reaction to the presence of calcium in the mitochondria and sarcotubular systems of the sarcoplasmic reticulum, and in the intrafibrillar spaces and in the Z and M lines of the sarcomeres calcium concentrations are not detectable. The authors checked the results by using the method of Carasso-Favard (1966).