10.1371/journal.pone.0065969.g001 Joseph Zacharia Joseph Zacharia Joseph R. H. Mauban Joseph R. H. Mauban Hema Raina Hema Raina Steven A. Fisher Steven A. Fisher Withrow G. Wier Withrow G. Wier Receptors for sympathetic neurotransmitters activate at least 80% of contractile tone in mouse femoral arteries <i>in vivo</i>. Public Library of Science 2013 Anatomy and physiology Musculoskeletal system muscle Muscle functions cardiovascular system neuroscience neurophysiology neuromuscular junction cardiovascular Cardiovascular imaging Cardiovascular pharmacology Vascular biology Drugs and devices sympathetic neurotransmitters activate contractile femoral arteries 2013-06-12 02:06:57 Figure https://plos.figshare.com/articles/figure/_Receptors_for_sympathetic_neurotransmitters_activate_at_least_80_of_contractile_tone_in_mouse_femoral_arteries_in_vivo_/717617 <p>(A) Upper panel: 5 (a–e) successive transverse line-scan images of a femoral artery <i>in vivo.</i> Artery diameter was obtained as the distance between the two peaks in fluorescence intensity, representing the fluorescence within the walls of the artery. Artery diameter was measured only during the final 10 seconds of a 10 min duration control period or exposure to an antagonist. There is thus a 10 minute gap between each image (a–e) and between each corresponding diameter trace in the lower panel. Lower panel: Artery diameter under each condition (a–e). (a) Control, represents artery in basal state of anesthetized animal. (b–e) Arterial diameter upon on cumulative exposure to RS79948 (0.1 µM) (b), Prazosin (0.1 µM) (c), Suramin (0.5 mM)+BIBP3226 (1 µM) and (e). 0[Ca<sup>2+</sup>]. (B) Average data from 6 arteries. Fractional diameter is the measured diameter divided by the passive diameter for each artery, measured in the presence of 0[Ca<sup>2+</sup>] solution. In the combined presence of α<sub>1</sub>-, α<sub>2</sub>- adrenoceptor, NPY<sub>1</sub> and P<sub>2X</sub> receptor blockers, active vascular tone was reduced to less than 20% of the control level. As shown later, α<sub>1</sub>-adrenoceptors are not fully blocked at the concentration of prazosin used (0.1 µM), and thus the tone activated by noradrenaline is greater than shown here. Significance of difference from previous drug treatment, <sup>*</sup><i>P</i><0.05, <sup>**</sup><i>P</i><0.01, <sup>***</sup><i>P</i><0.001 (ANOVA followed by Newman-Keuls multiple comparison test).</p>