Molecular mechanism of calcium ion transport in mitochondria. I. Glycoprotein-peptide complex as a component of the electron transport system

The molecular structure of the mitochondrial glycoprotein capable of forming Ca2+-selective and ruthenium red-sensitive conductance channels when incorporating into a model membrane are studied. The glycoprotein is shown to be a complex consisting of the glycoprotein itself and a low-molecular component which may be attributed to the substance of a peptide nature. A technique is elaborated to divide the complex into constituents. It is found that the channel-forming part of the complex is its peptide component. The glycoprotein component is unable to transport Ca2+ and, probably, fulfills a regulatory function.     

Development of ovaries in bovine fetuses

The growth of ovaries, development of germ cells, formation of sex cords, folliculogenesis and dependence of these processes on the gonad morphogenesis stages were studied on 68 embryos and foetuses at the age of 1.5 to 9 months. Sex differentiation of ovaries was shown to take place in 1.5 month old embryo. The cords of connective tissue's cortical stroma appear also in 1.5 month old embryo, they develop in the dorsoventral direction and reach the gonad's covering epithelium in 6 month old foetuses. The formation of the medulla rudiment starts in 1.5 month old embryo when the gonad is separated from mesonephros and connected with it via the ovary gate. In 4 month old foetuses the ovary net transforms into a stellate structure. Important morphogenetic processes, such as the development of the ovary somatic elements, entry of the oocytes into meiotic prophase, formation of the sex cords and folliculogenesis, develop in the dorsoventral direction Germ cells in 9 month old foetuses are enclosed into primordial or, growing follicles.     

Chemoreceptor function and metabolism of the carotid body in the rat

Using fluorimetric and polarographic determination of cell respiration, metabolic reactions of the carotid body of rats to adequate stimulation have been revealed. Functional relationships of the dose--effect type, which were found for these reactions, may be approximated by equations which are similar to those describing the unconditioned reflexes from the carotid chemoreceptors. However, reactions of the metabolics systems of the carotid body account for the perception of not all chemical stimuli, but only of acids and some alkaloids. These data reveal the heteregeneity of the carotid chemosensory system not only in the amphibians (which was known earlier), but in mammals as well.