The effects of alpha and beta-adrenergic stimulation on triacylglycerol secretion were investigated in isolated rat hepatocytes. Epinephrine within 3h of incubation suppressed triacylglycerol secretion by 35% and increased its cellular content by 18%. The inhibitory effect of epinephrine was abolished by inclusion of phentolamine and also prazosin but not with propranolol. Trifluoperazine c...

The rate of transcription of the beta 2-adrenergic receptor gene is increased in response to beta-adrenergic agonist stimulation of the receptor at the cell surface. This effect is mediated by stimulation of adenylyl cyclase and elevation of intracellular cAMP levels. We have previously shown that this responsiveness to cAMP resides in the 5'-flanking region of the human beta 2-adrenergic recep...

Multiple and paradoxical effects of airway smooth muscle (ASM) 7-transmembrane-spanning receptors activated during asthma, or by treatment with bronchodilators such as beta(2)-adrenergic receptor (beta(2)AR) agonists, indicate extensive receptor crosstalk. We examined the signaling of the prostanoid-EP(1) receptor, since its endogenous agonist prostaglandin E(2) is abundant in the airway, but i...

Orthovanadate (vanadate) inhibited the platelet aggregation induced by platelet-activating factor (PAF) in a dose-dependent manner. Propranolol, a nonspecific beta-adrenergic receptor antagonist, and H-8, a selective inhibitor of cAMP-dependent protein kinase (PKA), suppressed the inhibition of the PAF-induced platelet aggregation by vanadate. Vanadate increased the cAMP content in platelets ac...

BACKGROUND The family of A-kinase-anchoring proteins, AKAPs, constitutes a group of molecular scaffolds that act to catalyze dynamic interactions of protein kinase A, protein kinase C, tyrosine kinases, G-protein-coupled receptors and ion channels. AKAP5 (MW ~47 kDa) and AKAP12 (MW ~191 kDa) homo-oligomerize, but whether or not such AKAPs can hetero-oligomerize into supermolecular scaffolds of ...

introduction: the ginger rhizome has been widely used in traditional medicine for treatment of gastrointestinal diseases. in the present study the effect of ginger alcoholic extract on mechanical activity of isolated jejunum of male rats and also its interaction with cholinergic, adrenergic and nitrergic systems were investigated. methods: seven adult male wistar rats were anesthetized by ethyl...

The alpha 2 and beta 2 adrenergic receptors, both of which are activated by epinephrine, but which can be differentiated by selective drugs, have opposite effects (inhibitory and stimulatory) on the adenylyl cyclase system. The two receptors are homologous with each other, rhodopsin, and other receptors coupled to guanine nucleotide regulatory proteins and they contain seven hydrophobic domains...