Nervous modulation of spontaneous contractions in bovine mesenteric lymphatics.
1. Spontaneous isometric contractions were measured in 2 cm segments of bovine mesenteric lymphatics. 2. Field stimulation at 0.25, 1 anf 4 Hz increased the frequency of contraction. 3. Tetrodotoxin 3 x 10(-6) M blocked the response to electrical stimulation. 4. Phenoxybenzamine 3 x 10(-7) M converted the excitatory effect of stimulation to an inhibitory one. 5. Propranolol 3 x 10(-7) M potentiated the excitatory response to stimulation at 1 and 4 Hz. 6. Field stimulation was without effect in the presence of propranolol and phenoxybenzamine together. 7. Cocaine potentiated the response to stimulation at 0.25 and 1 Hz. 8. Atropine 3 x 10(-7) M failed to block the excitatory effect. 9. Field stimulation at 0.5 and 1 Hz increased the frequency of spontaneous contractions and propulsion of fluid by 8 cm cannulated segments of lymphatic. 10. The results suggest that bovine lymphatic vessels have a noradrenergic innervation which is capable of controlling lymph flow.
D000818:Animals; D001285:Atropine / Q000494:pharmacology; D002417:Cattle; D003042:Cocaine / Q000494:pharmacology; D004558:Electric Stimulation; D066298:In Vitro Techniques; D008208:Lymphatic System / Q000187:drug effects / Q000294:innervation*; D008643:Mesentery / Q000294:innervation; D009119:Muscle Contraction / Q000187:drug effects; D009130:Muscle, Smooth / Q000502:physiology; D010643:Phenoxybenzamine / Q000494:pharmacology; D011433:Propranolol / Q000494:pharmacology
D010643:Phenoxybenzamine; D001285:Atropine; D011433:Propranolol; D003042:Cocaine