Fig. 4.

Postprandial mesenteric lymphatic fluid (MLF) enhancement of transient increases in intracellular calcium concentration ([Ca²⁺]_i) in sensory nerves is abolished with the transient receptor potential vanilloid 1 (TRPV1) and transient receptor potential ankyrin 1 (TRPA1) antagonist ruthenium red (RR). After being preloaded with fura-2 AM (10 µM), dispersed mouse primary cultured dorsal root ganglia (DRG) neurons were rested in a Ringer solution containing 10 µM of the TRPV1 and TRPA1 pore blocker RR for 10 min before fura-12 imaging. MLF, capsaicin (Cap), and allyl isothiocyanate (AITC) were applied to the neurons as outlined in Fig. 2 and each contained 10 µM RR. To determine the importance of TRPV1 and TRPA1 on the postprandial MLF response of the sensory nerves, the transient increases in [Ca²⁺]_i in response to MLF from fed (black bars) or fasted (gray bars) rats was measured in the presence of RR. Blockage of channels was verified by the addition of Cap or AITC. Inhibition of both TRPV1 and TRPA1 channels abolished the differences in transient [Ca²⁺]_i observed in fed and fasted MLF of the vehicle controls (VC). Greater than 400 neurons were examined in 3 independent cultures from 4 mice. Bars are means ± SE. NFR, normalized fura-2 AM response; NS, not significant. **P < 0.01. Statistical analysis was by ANOVA using Tukey's post hoc test.