Radioprotective effect of Broncho-Vaxom on the development of latent injury in rat liver

The influence of immunomodulator Broncho-Vaxom on the rise and restoration of latent radiation injury in rat liver was studied. Broncho-Vaxom was admi nistered intraperitoneally at the dose of 1.5 mg/rat or 3 mg/rat 24 h befor e whole body irradiation with the doses of 3, 6 and 9 Gy of gamma radiation . Animals in all groups were partially hepatectomized (2/3 of liver mass re moved) within 30 min or on the 6th and 13th day after irradiation and exami ned on the 30th h after the operation, i.e, on the Ist, 7th and 14th day af ter irradiation. We have found that i.p. administration of 1.5 mg/rat reap. 3 mg/rat of Broncho-Vaxom 24 h before whole body irradiation with the dose s of 3, 6 and 9 Gy of gamma radiation resulted in an alleviation of latent injury. The alleviation has been manifested by smaller range of radiation-i nduced changes during regeneration of liver 30 h after partial hepatectomy. It is indicated by increasing of mitotic index (Fig. 1, Tab. I) and decrea sing of chromosome aberrations (Fig, 2, Tab. II) in comparison with irradia ted nonprotected animals. The range of radioprotective effect of investigat ed immunomodulatory agent has partially depended on the dose of Broncho-Vax om and radiation. It follows from our results that the Broncho-Vaxom has no t only radioprotective effect but favourable influence the processes of com pensational regeneration as well. Administration of 1.5 mg/rat and particul ary 3 mg/rat of Broncho-Vaxom 24 h before partial hepatectomy markedly stim ulated proliferation also in regenerative liver of non-irradiated animals ( Fig. 1, Tab. I). We suggest that stimulation of regenerative process of liv er after administration of immunomodulators Broncho-Vaxom including is not propably realised directly but via mediators released from stimulated liver macrophages Kuppfer cells (Simek et al., 1986; Beyer et al., 1990; Nagata et al., 1994).