title: Spontaneous activity in isolated bovine mesenteric lymphatics.
abstract: 1. Longitudinal tension was measured in isolated segments (approximately 20 mm in length and 2 mm in diameter) of bovine mesenteric lymphatic vessels.2. Seventeen out of thirty-nine vessels showed regular spontaneous rhythmic contractions, the most common frequency being about 2/min.3. The strength of each contraction was related to the duration of the preceding pause, a longer pause being associated with a stronger contraction.4. Noradrenaline increased the frequency and decreased the amplitude of the contractions. This effect was abolished by alpha-receptor blockade with phentolamine.5. Isoprenaline slowed the frequency of the contractions. This effect was abolished by beta-receptor blockade with propranolol.6. Acetylcholine had little effect on the rate of spontaneous contractions.
mesh_terms: D000109:Acetylcholine / Q000494:pharmacology; D000818:Animals; D002417:Cattle; D066298:In Vitro Techniques; D007545:Isoproterenol / Q000494:pharmacology; D008208:Lymphatic System / Q000187:drug effects / Q000294:innervation / Q000502:physiology*; D008643:Mesentery / Q000502:physiology*; D009119:Muscle Contraction / Q000187:drug effects*; D009638:Norepinephrine / Q000494:pharmacology; D010646:Phentolamine / Q000494:pharmacology; D010812:Physical Stimulation; D011433:Propranolol / Q000494:pharmacology
chemical_list: D011433:Propranolol; D007545:Isoproterenol; D000109:Acetylcholine; D009638:Norepinephrine; D010646:Phentolamine