Effect of chalone and antichalone on free radical processes in rat liver

Abstract

Effect of the proliferative regulators chalone and antichalone on the free radical system is studied on isolated and perfused rat liver under normal conditions and after ammonium chloride load (5 mM). It is shown that chalone suppressed both lipid peroxidation and antiradical system, while antichalone exhibits opposite effects on these processes. Ammonium chloride abolishes the effect of antichalone and does not change the effect produced by chalone. A hypothesis is proposed that specific function of the organ predominates over its response to local regulatory stimuli.Key Words: chalone; antichalone; isolated liver; lipid peroxidation; antiradical activityThe majority of studies in the field of regulation of cell homeostasis are aimed at investigating final effects of regulatory factors and usually employ morphological methods. Such an approach ignores cell processes which occur after the regulatory stimulus reaches the cell to the appearance of morphological changes triggered by this signal. These processes occurring during the lag-period prepare the target cell to competent response to the action of growth factors. MATERIALS AND METHODSIsolated livers from random-bred albino rats of both sexes (221+3 g) were used in the experiments. The animals were sacrificed in the morning after 24-h fasting. The liver of ketamine-narcotized and heparinized rat was connected via v.portae to a perfusion system as descnSed previously [2]. Then it was isolated from ligaments, removed from the abdominal cavity, and placed into a thermoeontrolled perfusion chamber. At the first stage the liver was perfused for 30 rain with Hank's medium (37~ pH 7.45, 5 ml/min) for stabilization of metabolic processes. During the next 30 rain the liver was perfused under the same conditions with experimental solutions containing ehalone, antiDepartment of Medical Biology and Genetics, N. N. Burdenko State Medical Academy, Voronezh chalone, 5 mM NH~C1, or a combination of growth factor with NH4CI. The preparations were added in a proportion of one dose per 10 ml. The dose was calculated on the basis of the antioxidant properties of chalone and antichalone discovered by A. N. Pashkov [4]. The amount of preparation inducing 50% quenching of chemiluminescence was taken as one dose.After the end of perfusion, the liver was frozen in liquid nitrogen and then homogenized in physiological saline containing Triton X-100 and centrifuged for 10 min at 15.000 g min. The contents of protein (by the method of Lowry) and malonic dialdehyde (MDA) [7] in the supernatant were measured. Antiradical activity of the supernatant was evaluated by chemiluminescence quenching on an KhLMITs-01 chemiluminometer [3].The significance of differences was evaluated by one-factor dispersion analysis. RESULTSOur results show that cell proliferation regulators specifically modulate such phylogenetically old protess as lipid peroxidation (LPO).As seen from Fig. 1, ehalone and antichalone had opposite effects on the intensity of LPO, judging from the content of MDA in isolated liver. ...

Effect of epiphysectomy on the circadian dynamics of antiradical activity of chalone-antichalone system of albino rat liver

“…Since the hepatic chalone inhibits LPO and the antiradical component of the free-radical system, while antichalone stimulates antiradical activity [7], it seems that during the night hours, in the active phase of antiradical activity of the liver CAS, the chalone/ antichalone proportion is shifted towards the latter. Passive phase of the antiradical activity CR observed during the daytime is caused by reduced concentration of antichalone and predominance of the chalone component.…”

“…Antiradical activity of hepatic chalone and antichalone preparations was evaluated by chemiluminescence quenching in a system generating free radicals and expressed in arbitrary units per mg protein. It is known that hepatic chalone reduces, while antichalone increases the antiradical activity of a system generating free radicals [7]. The mixture of hepatic chalone and antichalone was prepared and their antiradical activity was evaluated at Department of Medical Biology and Genetics (headed by Professor A. N. Pashkov) of N. N. Burdenko State Medical Academy, Voronezh.…”

Relationship between Proliferation of Ehrlich Ascitic Tumor Cells and Status of the Chalone System under Conditions of Modified Photoregimen

“…Photoperiodicity is essential for proliferation of cells, including cells of Ehrlich ascitic tumor (EAT) [7,10]. Of factors involved in local (tissue) regulation of the proliferative system, chalones, tissue inhibitors of cell proliferation, play the key role [2,5,6,8,9]. However, the interactions between these levels of regulation of temporal organization of the proliferative system are little studied.…”