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Ceruloplasmin (CP) expression at the level of formation of its molecular forms in the liver and other rat organs during ontogenesis has been studied. The synthesis of CP commenced on day 15th of embryogenesis and coincided in time with the completion of formation of the fetal liver. This period of rat embryo development was marked by the appearance of two molecular forms of newly formed CP, one of which was secreted in vitro by isolated fetal liver, while the other one was found in the membrane fraction of extrahepatic embryonic tissues. The proportion of CP among the total protein of these fractions increased up to term, correlating with the gain in the embryo weight. The relative content of CP secreted by the livers of newborn animals remained constant up to day 9th of postnatal life and then increased with the age up to approximately 1.5 months. At the same time, the serum concentration of CP remained constant up to day 19th of postnatal life. The increased rate of secreted CP synthesis in the liver during ontogenesis coincided with the appearance of a newly formed non-secreted membrane-bound form of CP in hepatocytes. The ontogenetic dynamics of synthesis of various molecular forms of CP in the liver correlated with the results of immunoblotting of CP polypeptides in Golgi membranes isolated from the livers and the livers and the liver of a 30-day-old rat.

The effect of alimentary administration of silver salts upon embryogenesis in rats has been studied. Feeding of AgCl to pregnant female rats throughout gestation did not result in any alterations in their physiological functions, although the active copper-containing ceruloplasmin (Cp) was eliminated from the blood stream. However, anomalous development of embryos, their prenatal death or total mortality of newborn rats within the first 24 hours after birth were evidenced. The copper content in the placenta and embryonic tissues decreased appreciably. The Cu,Zn-superoxide dismutase (SOD) activity was diminished in the cytoplasm of embryonic cells alongside with its drop, though less pronounced, in the tissues of the pregnant females. The embryotoxicity of AgCl was considerably reduced by repetitive injections of native Cp to pregnant rats. Such treatment caused an increase in the SOD activity in the placenta and embryonic tissues. Mortality of the newborns also went down. It is suggested that the embryotoxic effect of AgCl is due to its ability to interfere with copper metabolism, by altering the copper-transporting function of Cp.

Some peculiarities of rat milk ceruloplasmin (CP) biosynthesis have been analysed. Electrophoretic and immunoelectrophoretic data suggest that rat milk contains up to 20 mg/100 ml of CP. Rat milk CP is represented by a single molecular form whose molecular mass, enzymatic activity and antigenic properties are fully identical with those of serumal CP. According to the dot hybridization date, the CP-mRNA content in rat mammary cells is about ten times as low as that in adult rat liver. Analysis of polyribosomal RNA by blot hybridization of RNA-cDNA revealed that rat mammary CP-mRNA is represented by a single molecular form, 3.5 kb in length, whose molecular mass is identical with that of the predominant CP-mRNA of rat liver. The dynamics of secretion of the de novo synthesized CP into rat milk indicates that the CP synthesis and secretion occur independently of the serumal CP. In vitro and in vivo pulse labelling studies demonstrated that rat milk CP is synthesized and secreted by rat mammary cells.

Amniotic fluid from women was injected intra-amniotically to rats at the 14th day of pregnancy in a dose 0.3 ml. Morphological and functional parameters of embryonic development of rats and EMG activity of rat puppies at the age of 30-34 days differed from control ones with respect to the degree of maturity and motor disturbances of newborn babies. The data obtained reveal not only evident but also masked forms of motor pathology which was observed in children later, namely to 6-9 months. Chronic motor pathology in rat puppies was unilateral with central motor disturbances in babies being directly related to the degree of these disturbances.