RESUMEN
Low-intensity radiation at the absorbed dose of 4 µGy/min is a stressor of medium strength. In male Wistar rats, a pronounced and long-lasting response occurs in the system of red blood cells at the accumulated dose of 4.8 mGy. Functional deficiency of circulating cells was evaluated by the resistance of erythrocytes to acid lyse and the activity of the main antioxidant enzymes--superoxide dismutase (SOD) and catalase (CAT). The minimum "threshold" doses of radiation that cause systemic reactions occur in the range of units of miligrey.
Asunto(s)
Catalasa/sangre , Eritrocitos/efectos de la radiación , Dosis de Radiación , Superóxido Dismutasa/sangre , Animales , Catalasa/efectos de la radiación , Eritrocitos/enzimología , Rayos gamma , Masculino , Ratas , Superóxido Dismutasa/efectos de la radiaciónRESUMEN
Our work was aimed at researching into the influence of dipeptide (gamma-dGlu-dTrp) "Timodepressin" and this dipeptide-based tripeptides on the colony-forming ability of the irradiated in vitro bone marrow and hemopoietic stem cells of the normal organism. Also studied was the effect of various doses (1-1000 microg/kg) of one oftripeptides (dAla-gammadGlu-dTrp) on the output of exogenous splenic colonies in the case of its introduction 48 hours before irradiation. It is shown that the mode of influence of the preparations produced on the basis ofdipeptides dGlu-dTrp and gamma-dGlu-dTrp on the initial stages ofa hemopoiesis in the normal and irradiated organism depends on the nature of the additional amino-acid residue and its optical orientation.
Asunto(s)
Trasplante de Médula Ósea , Médula Ósea , Rayos gamma/efectos adversos , Células Madre Hematopoyéticas , Oligopéptidos/farmacología , Protectores contra Radiación/farmacología , Animales , Médula Ósea/efectos de los fármacos , Médula Ósea/efectos de la radiación , Ensayo de Unidades Formadoras de Colonias , Relación Dosis-Respuesta a Droga , Femenino , Células Madre Hematopoyéticas/citología , Células Madre Hematopoyéticas/efectos de los fármacos , Células Madre Hematopoyéticas/efectos de la radiación , Ratones , Ratones Endogámicos C57BL , Ratones Endogámicos CBA , Oligopéptidos/química , Protectores contra Radiación/química , Relación Estructura-ActividadRESUMEN
The prolonged ionizing radiation exposure at the absorbed doze rate of 2.6 mGy/hour and the total accumulated doze of about 20 cGy during different periods of the intrauterine development caused disorders of a coordinated development of organs and the decrease of endurance in physical activity in the postnatal ontogenesis of the irradiated posterity. The results obtained are comparable to the consequences of irradiation exposure of the fetus at the accumulated doze of 125 cGy during all stages of pregnancy and give grounds for considering radiation exposure at the above-mentioned rate (20 cGy) as a biologically significant factor.
Asunto(s)
Pesos y Medidas Corporales , Relación Dosis-Respuesta en la Radiación , Desarrollo Embrionario/efectos de la radiación , Animales , Femenino , Rayos gamma , Embarazo , Ratas , Ratas WistarRESUMEN
We have performed structural and functional studies of the hemotropic activity for a number of novel 2,5-diketopiperazine peptidomimetic derivatives. We employed a mouse model of hemopoietic stem cells cloning in the spleen of lethally irradiated animals. Biologic activity of synthetic products was studied in two experimental models: 1) in vitro irradiated bone marrow SFU-S was used for studying the radio modifying activity; 2) the biological effect of peptidomimetics on the intact non-irradiated bone marrow was evaluated in vivo. Various ways of administration of the peptidomimetics studied were used in the in vivo experiments: intravenous, intraperitoneal or subcutaneous injections and oral administration in the dose range of 10-10000 microg/kg. As a result of our work, we have discovered 2,5-diketopiperazine peptidomimetic derivatives with the dual activity: stimulation of intact committed SFU-S and radiomodifying activity.