Does the autonomic nervous system regulate whole-body lymph flow?
We compared whole-body lymph flow responses with and without the autonomic nervous system intact in pentobarbital-anesthetized, acutely nephrectomized dogs. We measured left thoracic duct lymph flow, lymph and plasma protein concentrations, arterial and venous pressures, heart rate, and hematocrit in eight intact and six ganglion-blocked (hexamethonium, 15 mg/kg iv) animals. Ganglionic blockade lowered arterial pressure and heart rate but did not change lymph flow rate or the other variables. In the control and blocked groups at 30-min intervals, isotonic saline, lactated Ringer, and Dextran 70 solutions were serially infused, followed by hemorrhage and reinfusion of shed blood. Infusions or withdrawals were equal to 2% of body weight and were induced over 5-min intervals followed by 25 min of recovery. Lymph flow generally increased to a peak 5-7 min after each infusion was ended and then decayed back toward preinfusion levels; the extent of the rise in lymph flow, the time of the pea
