Figure 4. Pressure–volume behaviour of submesothelial lymphatics.

A, example of the relationship between cumulative injected volume (V_injected) and P_lymph-peak attained after each injection in a single experiment. The continuous line identifies the highly significant linear regression through the initial data points (filled symbols). At further injections and larger cumulative injected volumes (open symbols), P_lymph-peak was almost unchanged suggesting fluid leakage through vessel discontinuities. B, plots obtained by pooling data from all lymphatic segments (represented by different symbols), where V_injected is plotted as a function of ΔP_lymph-peak to account for the physiological variability of individual pre-injection P_lymph. The data points appear distributed in two distinct populations characterized by a significantly (P < 0.005) different C_lymph amounting to 6.7 nl mmHg⁻¹ (high compliance, H-C_lymph) and 1.5 nl mmHg⁻¹ (low compliance, L-C_lymph), respectively. C, comparison between absolute L-C_lymph and H-C_lymph values, expressed in nl mmHg⁻¹. Bars represent means ± s.e.m. *Significantly different (P < 0.001) from L-C_lymph.