[Potentiometric determination of halide ions in blood].

The authors have studied the possibility of using ion-selective electrodes Kritus (Czecho-Slovakia) for analysis of whole blood and serum without preliminary labor-consuming sample preparation. Chloride ions were found to be detectable in the blood serum by potentiometric titration with Ag nitrate solution making use of a pAg-CE-pF-CE pair in ethanol, acetone, or acetic acid medium. Active concentrations of whole blood and serum bromide- and iodide ions may be measured by direct potentiometry with pBr-CE-pF-CE and pI-CE-pF-CE pairs, respectively, against the background of 1 M potassium (or sodium) nitrate solution providing the constancy of solution ionic strength.

[Lipid peroxide metabolism in chemical carcinogenesis].

Lecithin and kephalin content in the microsomes and mitochondria of the rat liver, and also the activity of enzymatic and nonenzymatic systems of the phospholipid peroxidation showed a sharp change following 3,4-benzpyrene injection. Carcinogenesis is accompanied by significant changes in the lipid peroxides content and in the activity of the enzyme utilizing lipoperoxides (glutathion peroxidase, glutathion reductase). Accumulation of lipid peroxides in the rat liver in carcinogenesis was connected with disturbed balance of the generating systems and detoxication of lipid peroxides in the tumour is attributed to the high activity of the protective enzymatic systems and serves as a reflection of the adaptation mechanisms directed to the maintenance of a high pool of proliferating cells in the tumour.

[Effect of sarcolysine on glutathione peroxidase and glutathione reductase activity in sarcoma C-45].

A drop of glutathione peroxidase and glutathione reductase activity was revealed in sarcoma C-45 at the period of its most intensive growth. Repeated sarcolysine injections (1.2 mg/kg, intraperitoneally) caused a sharp fall in the activity of both enzymes with a simultaneous reduction of the ratio of glutathione reductase and glutathione peroxidase activities.

[Change in the concentration of total lipids, phospholipids and neutral lipids in rat liver mitochondria and microsomes during chemical carcinogenesis].

Sharp increase in the content of total lipids and, especially, neutral lipids, and considerable decrease in the content of phospholipids were observed in liver microsomes and mitochondrias from liver of tumour-bearing rats in the process of the growth of sarcoma, induced by a single injection of 3,4-benzpyrene. The injection of anthracene, a non-cancerogenous hydrocarbon, practically did not affect the lipid composition of rat liver subcellular particles. Thus, the disturbances in normal functioning of subcellular particles under cancerogenesis are due to considerable change in the chemical composition of biomembranes.