Fig. 5.
Blockade of ryanodine receptors (RyRs) with ryanodine leads to a loss of phasic contractions and limited substance P (SP)-induced contraction. Representative trace of diameter over time of an isolated rat collecting mesenteric lymphatic vessel treated with 10−5 M ryanodine (A). The continuation of the trace shows a later time period in the same experiment with ryanodine, when 10−8 M SP was added. The boxes beneath the trace represent the time periods during which the quantitative data used for comparisons in B–D were collected. The mean diameter (B), mean tone (C), and maximum tone (D) for the time periods before addition of SP, 0–30 s after SP addition, and 31–150 s after addition of SP were compared using a repeated measures ANOVA model followed by Dunnett’s comparison with control (baseline period). P values for the comparisons are shown. N = 6 lymphatics. Each lymphatic studied was obtained from a unique rat. NS, not significant.