Five repeated submaximal treadmill exercises at 2 h intervals following a maximal test prolong walking distance and reduce haemorheological derangement in a second maximal test in patients affected with peripheral obliterative arterial disease (POAD). An increase in adenosine plasma levels is observed during maximal tests, thus suggesting the possibility of an ischaemic preconditioning of lower limbs. The intravenous infusion of 50-100-200 mg buflomedil, and the oral administration of 300-600-900 mg of the drug in POAD patients, also produce an increase in plasma levels of adenosine. Finally, 600 mg buflomedil orally at 12 h intervals produced pulse increase in adenosine plasma levels without any accumulation of the drug or adenosine for at least one week. The possibility of a pharmacological preconditioning of ischaemia is suggested.