Thoracic Duct Lymph and Lymphocytes in the Guinea Pig

Effects of Hypoxia, Fasting, Evisceration and Treatment With Adrenaline

¹ From the Department of Anatomy, University of Bristol, Bristol, England

The guinea pig is a suitable animal for the collection of thoracic and cervical duct lymph. Values have been ascertained for lymph flow and lymphocyte output in the anesthetized male guinea pig under various experimental conditions. Evidence is presented which suggests the existence of a diurnal rhythm in level of thoracic duct output of lymphocytes. Effects of fasting and of hypoxia have been observed as examples of stimuli operating within a physiological range. Effects of interventions such as evisceration, biliary obstruction and fistulation, and treatment with adrenaline have also been observed. As compared with normal values, hypoxia was found to be an adequate stimulus to produce an increase in lymph flow and lymphocyte output. Fasting and treatment with adrenaline produced decreased lymphocyte output by the thoracic duct. Evidence provided by study after evisceration suggests that about 95% of the cells in the thoracic duct are derived from the lymphatic tissues associated with the gastroenteric tract and related tissues, residual thoracic duct lymph flow after evisceration being of the same order of magnitude as for the cervical lymph ducts. Obstruction of the common bile duct increased thoracic duct lymph flow as compared with the decrease produced by biliary fistulation. Removal of the thymus was associated with a marked decrease in the output of thoracic duct lymphocytes in both normal and splenectomized guinea pigs. Splenectomy was not associated with such a decrease in thoracic duct lymphocyte output.