Prevention of cerebral stroke by arotinolol in salt-loaded SHRSP

The preventive effects of long-term treatment with arotinolol on the development of cerebral stroke were examined in SHRSP fed a high salt diet. Arotinolol (4.87 mg/kg per day for 20 weeks) prevented cerebral lesions, reduced signs of stroke and delayed early mortality but did not alter blood pressure from control SHRSP, when the administration of the drug was started before the onset of hypertension. At dosage levels similar to arotinolol, both pindolol and labetalol were less effective in preventing cerebral lesions despite lower blood pressure. Propranolol produced no detectable effect on blood pressure or frequency of cerebral lesions. Furthermore, arotinolol (4.27 mg/kg per day) markedly inhibited the development of stroke without blood pressure reduction, when the administration was started after the onset of severe hypertension. These results suggest that arotinolol is more effective in preventing cerebral stroke than pindolol, labetalol and propranolol, and that factors other than blood pressure reduction may be involved in this preventive effect.