Local and systemic effects of peritoneal lavage with high concentrations of adenosine in rats

Background: Adenosine exerts actions which may be beneficial in treating di seases of the gastrointestinal tract. However, administered systemically, a denosine causes a 'stress reaction' and may adversely affect blood pressure and cardiac and renal function. Aim: To determine whether peritoneal lavage with adenosine provides pharmac ological levels of adenosine in the intestines without elevating adenosine levels in the systemic circulation. Methods: Rats received an intramesenteric artery infusion of angiotensin II (30 ng/min) plus methoxamine (3 mug/min) to reduce mesenteric blood flow b y approximately 60%, and adenosine solutions were instilled into the abdomi nal cavity. In a second study, microdialysis probes were placed in the mese nteric vein and aortic arch of rats, and the peritoneal cavity was continuo usly lavaged with adenosine solutions. Results: High concentrations (10(-3) M) of adenosine normalized the mesente ric blood flow without affecting blood pressure or heart rate. High concent rations of adenosine (10(-3) M) induced micromolar levels of adenosine and inosine in the mesenteric vein, without affecting adenosine or inosine leve ls in the aorta. Conclusions: Peritoneal lavage with high concentrations of adenosine provid es pharmacological levels of adenosine in the gastrointestinal tract withou t systemic side-effects. Peritoneal lavage with high concentrations of aden osine may be useful for the treatment of a number of diseases of the gastro intestinal tract.