Influence of spontaneous contractions of the lymphatic vessels on the lymphatic absorption rate of the peritoneal cavity in CAPD.

The lymphatic vessels have sympathetic innervation. Noradrenaline increases the number of spontaneous contractions of the lymphatic vessels, whereas isoprenaline slows these contractions. The purpose of this study was to analyze the influence of the blockade of spontaneous contractions of the lymphatic vessels on the lymphatic absorption rate (LAR) in 6 patients on continuous ambulatory peritoneal dialysis (CAPD) by using 0.12 mg of isoprenaline added to 2 L of 2.5% dextrose dialysis solution. This dose of isoprenaline has been shown to inhibit bovine mesenteric lymphatic contractions. The LAR was measured by the quantification of the intraperitoneal disappearance of dextran 70 added to this same dialysis solution during a 4-hour dwell. All patients were submitted to a control test without isoprenaline. The LAR was 0.57 +/- 0.19 and 0.65 +/- 0.38 mL/minute (p > 0.05), with and without isoprenaline, respectively. We conclude that spontaneous contractions of the lymphatic vessels do not play an important role in the lymphatic drainage mechanism of the peritoneal cavity. The diaphragmatic contractions seem to be more important, since drugs that interfere with such diaphragmatic mechanisms alter the LAR.