Authors: T Sjoberg ( ) , S Steen ( )
Lower leg lymphatics, taken from seven volunteers, were investigated in vitro. Isometric contractions were induced by noradrenaline, 5-hydroxytryptamine (5-HT), prostaglandin F2α (PGF2α), and the thromboxane A2 (TXA2)-mimetic U-44069. Noradrenaline induced phasic contractions in 6 of 7 segments. The amplitude of the contractions were up to 100% of a previous K+ (124mM)-induced contraction and the frequency at 10-6M of noradrenaline was 5-13 min-1. These contractions were unaffected by propranolol (10-6M), but they were abolished by phentolamine (10-6M). Noradrenaline had an Emax (tonic contraction) of 7% of the K+ (124mM) contraction (n = 7) and the pEC50-value was 6.9 (n = 3). The corresponding values for 5-HT were 21% (n = 5) and 6.4 (n = 3). PGF2α elicited contractions in all segments investigated (Emax = 87%, pEC50 = 5.8, n = 5). U-44069 had high contractile capacity and potency in all investigated segments (Emax = 137%, pEC50 = 8.9, n = 7). Phasic contractions were elicited also by 5-HT, PGF2α and U-44069. Compared to earlier studies of human peripheral lymphatics, these results show that there are regional differences in susceptibility to these vasoactive agents.
How to Cite: Sjoberg, T. & Steen, S. (1991) “CONTRACTILE PROPERTIES OF LYMPHATICS FROM THE HUMAN LOWER LEG”, Lymphology. 24(1).