Presence of interferon in venous blood draining from gut-associated lymphoid tissue

The question has been examined of whether interferon (IFN), produced in the microenvironment of the gut-associated lymphoid tissue (GALT) during the physiological response, is consumed locally, or whether some spills over and is drained into the general circulation. Plasma IFN levels were measured in venous blood draining from abdominal organs that are normally in contact with exogenous and endogenous interferon inducers. The results obtained from three rodent species indicate the presence of a venous-arterial and GALT venous-peripheral venous gradient, suggesting that at least some of the IFN produced in the GALT and spleen is absorbed via blood capillaries and detectable in the regional vessels. Owing to the rapid turnover of IFN, arterial or peripheral venous blood showed a basal level. The antiviral activity (AA) in rat and mouse blood appears to be attributable to IFN-gamma.