Figure 4. Effect of cardiac and respiratory activity on interstitial (P_int) and lymphatic (P_lymph) fluid pressure.

A, cardiogenic oscillations of diaphragmatic interstitial (b, P_int) and intraluminar lymphatic pressure (c, P_lymph), measured through the micropuncture technique in anaesthetized rats under neuromuscular blockade. Both diaphragmatic P_int and P_lymph oscillate almost in phase with arterial systemic pressure (a), shifting from a minimum to a maximum value during cardiogenic oscillations (modified from Negrini et al. 2004). B and C, simultaneous recording of respiratory tidal volume (V_T, top panel), lymphatic (P_lymph; continuous lines) and interstitial (P_int; dashed lines) pressures obtained in intercostal lymphatics of supine anaesthetized rats during spontaneous breathing (B) or mechanical ventilation at similar V_T and at zero alveolar end-expiratory pressure (C) (modified from Moriondo et al. 2005).