Possible benefit of selective beta 2-blockade in orthostatic hypotension a 'model' study in the cat.

In anesthetized cats head-up tilt was associated with a marked beta 2-adrenergic dilator interaction with the evoked constrictor response in the resistance vessels. The beta-adrenergic inhibition of vascular tone was revealed by measurements of total peripheral resistance and of regional resistance in skeletal muscle and in the intestine. Tentatively, the results may suggest that 'selective' blockade of vascular beta 2-adrenoceptors can be beneficial in states of orthostatic hypotension.