Adrenergic beta-receptor sensitivity of six male patients with essential tremor and six age-matched normal controls was assessed by measuring the response in the heart rate and postural tremor to incremental injections of the adrenergic beta-agonist isoprenaline. The relative increase in heart rate and tremor in essential tremor patients did not differ from that in normal controls. It is conclu...

Recent electrophysiological studies with cell membrane patches of cardiac myocytes and an electrically excitable cell line derived from rat pituitary tumor suggested that voltage activated calcium channels must be phosphorylated to respond to membrane depolarization (Armstrong and Eckert 1986; Trautwein and Kameyama 1986). In view of the "phosphorylation hypothesis" we investigated the adenylat...

The beta-adrenergic receptor kinase is an enzyme, possibly analogous to rhodopsin kinase, that multiply phosphorylates the beta-adrenergic receptor only when it is occupied by stimulatory agonists. Since this kinase may play an important role in mediating the process of homologous, or agonist-specific, desensitization, we investigated the functional consequences of receptor phosphorylation by t...

Agonist-promoted desensitization of adenylate cyclase is intimately associated with phosphorylation of the beta-adrenergic receptor in mammalian, avian, and amphibian cells. However, the nature of the protein kinase(s) involved in receptor phosphorylation remains largely unknown. We report here the identification and partial purification of a protein kinase capable of phosphorylating the agonis...

Propranolol is a nonselective beta-adrenergic receptor blocking agent possessing no other autonomic nervous system activity. It specifically competes with beta-adrenergic receptor agonist agents for available receptor sites. When access to beta-receptor sites is blocked by propranolol, the chronotropic, inotropic, and vasodilator responses to beta-adrenergic stimulation are decreased proportion...

Primary adipocytes were isolated from axillary brown adipose tissue from adult cynomolgus monkeys. That this tissue contained brown adipocytes was verified by morphological examination and by demonstrating the presence of uncoupling protein messenger ribonucleic acid in the isolated adipocytes. The contributions of beta 1-, beta 2-, and beta 3-adrenergic receptors (AR) to lipolysis and oxygen c...

The importance of beta-adrenergic signaling in the heart has been well documented, but it is only more recently that we have begun to understand the importance of this signaling pathway in skeletal muscle. There is considerable evidence regarding the stimulation of the beta-adrenergic system with beta-adrenoceptor agonists (beta-agonists). Although traditionally used for treating bronchospasm, ...

Characterization of adrenergic receptors in membranes from the rat seminal vesicle was studied by radioligand binding assay. Seminal vesicle membranes contained saturable and high affinity binding sites for the beta-adrenergic receptor antagonist 3H-dihydroalprenolol (3H-DHA) and for the alpha-adrenergic antagonist 3H-prazosin. The observed order of potency for adrenergic agonists in competing ...

Compared with adipose tissue from other mammals, porcine adipose tissue has stringent specificity for stimulation of lipolysis by analogs of norepinephrine. This study was to ascertain whether the specificity for control was reflected in the concentration of tissue cyclic AMP (cAMP). Adipose tissue slices were incubated and concentrations of tissue cAMP and free fatty acids (FA) released to the...