Articles

IN VITRO EFFECTS OF A THROMBOXANE A₂-ANALOGUE U-46619 AND NORADRENALINE ON CONTRACTIONS OF THE HUMAN THORACIC DUCT

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Abstract

A piece of a human thoracic duct removed at operation was investigated in organ baths. The duct was cut in 8 ring segments each about 1mm long and isometric tension recorded. The segments were exposed to a potassium rich (124mM) Krebs buffer solution. In only two of the segments were contractions induced (7.2 and 1.0mN, respectively). Noradrenaline and the thromboxane mimetic U-46619 induced tonic and phasic contractions. At a noradrenaline concentration of 10^-5M the phasic contractions had a frequency of 5 min^-1. The highest frequency, 9 min^-1, was recorded with 3 x 10^-10M of U-46619 present in the bath. Noradrenaline had a mean E_max of 50% of the previous K⁺ (124mM)-induced contraction, and the mean pEC₅₀-value was 6.7. The E_max and pEC₅₀-values of U-46619 were 142% and 9.5, respectively. Postjunctional alpha-adrenoceptors and thromboxane A₂-receptors may play a role in the contractility of the human thoracic duct.

How to Cite:

Sjoberg, T. & Steen, S., (1991) “IN VITRO EFFECTS OF A THROMBOXANE A₂-ANALOGUE U-46619 AND NORADRENALINE ON CONTRACTIONS OF THE HUMAN THORACIC DUCT”, Lymphology 24(3), 113-115.