Figure 1.

Cardiovascular responses to adenosine (10⁻⁹ – 10⁻⁵ mol kg⁻¹ i.v.) in anaesthetized guinea-pig in the absence and in the presence of L-NAME (50 mg kg⁻¹ i.v.). Each point in the curves is the mean·±s.e. of 4 – 6 experiments; ^*P⩽0.05. Values are reported as per cent of resting mean blood pressure (BP) or heart rate (HR) just prior to starting the agonist dose-response curve: 47.7±4.5 mmHg and 338.8±27.0 beats min⁻¹ (control); 75.8±1.4 mmHg and 338.5±18.2 beats min⁻¹ (L-NAME-treated).