Peritoneal instillation of taurolidine or polihexanide modulates intestinal microcirculation in experimental endotoxemia

Background and aims: Treatment of peritonitis may include peritoneal lavage/instillation with anti-infective agents like taurolidine or chlorhexidine. Materials and methods: We examined the effects of peritoneal instillation (INST, 5-ml solution) with taurolidine (TAURO) or polihexanide (POLI-LS) on intestinal microcirculation using intravital microscopy (IVM) in experimental endotoxemia (15 mg/kg lipopolysaccharide i.v.; LPS) in the rat (n=8 each group), their direct effects on local small blood vessels, aortal rings, and myocardial strips in vitro, as well as plasma interleukin levels. Results: It was found that LPS produced hypotension (98.8±9.5 vs 130.4±10.5 mmHg; mean arterial pressure [MAP], mean ± standard deviation [SD]), which was further pronounced after INST of TAURO (78.8±10.8; P<0.005) or POLI-LS (78.1±6.0; P<0.001). IVM revealed a reduction in temporary adhering leucocytes and an increase in firmly adhering leucocytes after INST with TAURO and POLI-LS. Both agents reduced functional capillary density either in the mucosa (POLI-LS vs sham: 259.7±54 cm/cm² vs 337.1±35.5) or longitudinal muscular layer in LPS rats (TAURO vs sham: 119.8±14.8 vs 153.7±11.0). POLI-LS induced local vasodilatation, whereas TAURO induced small vasoconstriction; in vitro, both agents showed vasodilating properties and did not have any effect on myocardial strip contraction. Conclusion: Some of the observed microcirculatory changes could be a result of the direct vascular effects of these agents.