Subtypes of functional alpha1-adrenoceptor.
In this review, subtypes of functional alpha1-adrenoceptor are discussed. These are cell membrane receptors, belonging to the seven-transmembrane-spanning G-protein-linked family of receptors, which respond to the physiological agonist noradrenaline. alpha1-Adrenoceptors can be divided into alpha1A-, alpha1B- and alpha1D-adrenoceptors, all of which mediate contractile responses involving Gq/11 and inositol phosphate turnover. A fourth alpha1-adrenoceptor, the alpha1L-, represents a functional phenotype of the alpha1A-adrenoceptor. alpha1-Adrenoceptor subtype knock-out mice have refined our knowledge of the functions of alpha-adrenoceptor subtypes, particuarly as subtype-selective agonists and antagonists are not available for all subtypes. alpha1-Adrenoceptors function as stimulatory receptors involved particularly in smooth muscle contraction, especially contraction of vascular smooth muscle, both in local vasoconstriction and in the control of blood pressure and temperature, and contraction of the prostate and bladder neck. Central actions are now being elucidated.
Department of Physiology, Royal College of Surgeons in Ireland, 123, St. Stephen's Green, Dublin 2, Ireland. docherty@rcsi.ie
James R
JR
Docherty
D000818:Animals; D001794:Blood Pressure / Q000502:physiology; D001833:Body Temperature Regulation; D054314:Drug Inverse Agonism; D043802:GTP-Binding Protein alpha Subunits, Gq-G11 / Q000378:metabolism; D007295:Inositol Phosphates / Q000378:metabolism; D051379:Mice; D018345:Mice, Knockout; D009130:Muscle, Smooth / Q000502:physiology; D009131:Muscle, Smooth, Vascular / Q000502:physiology; D018340:Receptors, Adrenergic, alpha-1 / Q000145:classification / Q000378:metabolism / Q000502:physiology*; D015290:Second Messenger Systems / Q000502:physiology; D014661:Vasoconstriction / Q000502:physiology
D007295:Inositol Phosphates; D018340:Receptors, Adrenergic, alpha-1; D043802:GTP-Binding Protein alpha Subunits, Gq-G11