Specificity of beta-adrenergic control of lipolysis in swine adipose tissue

Fenoterol (beta 2-agonist) and several analogs stimulated swine adipose tissue lipolysis in addition to epinephrine, norepinephrine and isoproterenol. Lipolytic activity was inhibited by propranolol (beta 1 + beta 2) greater than metoprolol (beta 1) greater than ICI 118,551 (beta 2) greater than practolol (beta 1) much greater than butoxamine (beta 2) regardless of the agonist used in the test system. The swine adipose adrenoceptor is not readily classified into a beta 1 or beta 2 subtype. It may be unique or the classification systems devised in laboratory animals may not be applicable across species.