@article{lymph 3210, author = {MK Ferguson, UE Williams, AR Leff, RW Mithchell}, title = {HETEROGENEITY OF TRACHEOBRONCHIAL LYMPHATIC SMOOTH MUSCLE RESPONSE TO HISTAMINE AND 5-HYDROXYTRYPTAMINE}, volume = {26}, year = {1993}, url = {http://journals.librarypublishing.arizona.edu/lymph/article/id/3210/}, issue = {3}, abstract = {<p>We assessed the responsiveness of tracheobronchial lymphatic smooth muscle to mediators of inflammation to determine whether homogeneous responses to histamine and 5-hydroxytryptamine (5-HT) are demonstrated among species typically used in studies of lymph vessels. Fresh porcine and bovine tracheobronchial lymph vessels were suspended from force-displacement transducers in baths containing oxygenated Krebs solution. Concentration-response curves were generated by cumulative addition of histamine (10<sup>-7</sup> to 10<sup>-3</sup> M) or 5-HT (10<sup>-7</sup> to 3 x 10<sup>-4</sup> M). Active tension (AT) was expressed in milligrams and as a percentage of initial vessel ring response to 65mM KCl. Histamine elicited concentration-dependent contraction, yielding maximum AT in porcine rings of 1116 +/- 127 mg (n = 39; 129.1 +/- 10.5% of KCl response) and in bovine rings of 733 +/- 106 mg (n = 20; 65.8 +/- 12.9%; P = 0.0005 for percent responses). PD<sub>2</sub> values (negative log<sub>10</sub> of the concentration at half-maximum effect) were 4.49 +/- 0.08 and 4.82 +/- 0.08; (P = 0.0034). 5-HT elicited concentration-dependent contraction, yielding maximum AT of 560 +/- 50 mg in porcine rings (n = 15; 97.2 +/- 9.7%) and 2892 +/- 454 mg in bovine rings (n = 27; 159.0 +/- 29%; P < 0.0001 for percent responses). PD<sub>2</sub> values were 6.25 +/- 0.05 and 5.28 +/- 0.04 (P < 0.0001). The data demonstrate a role for inflammatory mediators in the modulation of tracheobronchial lymphatic smooth muscle tone that is species- and mediator-specific, and support the potential for paracrine regulation of tracheobronchial lymph flow.</p>}, month = {9}, pages = {113-119}, issn = {2522-7963}, publisher={International Society of Lymphology and the University of Arizona Libraries}, journal = {Lymphology} }