The reaction of thymocytes to hypoxic stress.

The reaction of thymocytes to hypoxic stress has been investigated according to indices of nucleic acid exchange. Acute and moderate, though long-term, hypoxia noticeably depresses DNA and RNA syntheses in rat thymocytes. Activation of nucleic acid repair synthesis during restoration of the organ takes place only if the hypoxic effect alternates with periods of normoxia. Under conditions of continuous prolonged hypoxia (high altitude), the adaptation is achieved by a decrease in thymocyte nucleic acid exchange. The role of thymocytes in the homeostasis-maintaining mechanisms, as the organism becomes adapted to hypoxia through different training conditions, is discussed.