Effects of adenosine on [3H]norepinephrine release from perfused mesenteric arteries of SHR and renal hypertensive rats.

Adenosine (10-30 microM) inhibited the 3H-efflux evoked by sympathetic nerve stimulation in the perfused rat mesenteric arteries preincubated with [3H]norepinephrine. The inhibition was smaller in the prehypertensive (5 weeks old) as well as hypertensive (15-18 weeks) SHR (spontaneously hypertensive rats), compared with age-matched normotensive Wistar Kyoto rats. However, it was not diminished in Wistar rats rendered hypertensive by left renal artery occlusion. Thus, a diminished adenosine-mediated presynaptic inhibition of adrenergic transmission appears to be genetically inherent in SHR.