Alpha 1 adrenergic receptor

Power point is about alpha 1 receptor which is a G-coupled receptor and it's mechanism. How it is different from Alpha 2 receptor.

1. Alpha-1 adrenergic receptor Sabah Mansoor 2014-PhD-1070

2. Alpha-1 adrenergic receptor alpha-1 (α 1 ) adrenergic receptor is a  G protein Coupled Receptor  (GPCR) associated with the  Gq , heterotrimeric protein. more responsive to Norepinephrine than to epinephrine . Catecholamines like norepinephrine  (noradrenaline) and epinephrine   ( adrenaline) signal through the α 1 -adrenergic receptor in the central   and peripheral nervous systems.

3. Types of alpha receptors α- adrenoceptors exist on peripheral sympathetic nerve terminals and are divided into two subtypes   α 1 , and   α 2. α 1   is found mostly postsynaptically , whilst  α 2  although typically sited presynaptically , can also occur postsynaptically . Alpha 1 adrenergic receptor consists of three highly homologous subtypes, including α 1A , α 1B , α 1D - adrenergic.

4. α- Adrenoceptor Location and function Alpha 1 receptors are located on: all vascular smooth muscle, although densities vary throughout the body GI & urinary sphincters dilator muscle of the iris arrector pili muscle of hair follicles On central and peripheral nervous system

5. In the Central Nervous System they are found mostly postsynaptically and have an excitatory function. Peripherally they are responsible for contraction and are situated on vascular and on non-vascular smooth muscle.  α 1 -adrenoceptors on vascular smooth muscle are located intrasynaptically and function in response to neurotransmitter release. For non-vascular smooth muscle they can be found on the liver, where they cause hepatic glycogenolysis and potassium release. On the heart they mediate a positive inotropic effect. Cause relaxation of Gastro Intestinal smooth muscle and decrease salivary secretion .

6. Signaling Cascade

7. agonists and antigonists Alpha 1 agonists vasoconstrictive agents they are used to reduce edema and inflammation. naphazoline , phenylephrine and propylhexedrine . Alpha 1 antagonists causes vasodilation and decreased peripheral resistance; therefore they are used in the treatment of hypertension ( prazosin ). Treatment of benign prostatic hyperplasia . tamsulosin is a subtype-selective alpha 1A receptor that has more specificity toward smooth muscle in genitourinary tract .

8. REFERENCES Stedeford T, Cardozo-PF, Vultaggio B, Muro CC, Luzardo GE, Harbison RD. 2001. Alpha1-andrenergic receptors and their significance to chemical-induced nephrotoxicity—a brief review. Res. Commun . Mol. Pathol . Pharmacol . 110 (1-2): 59-72. Chen ZJ, Minneman KP. 2005. Recent progress in alpha 1-andrenergic receptor research. Acta Pharmacol Sin. 26 (11): 1281-7. Piascik MT, Perez DM. 2001. Alpha1-angrenergic receptors: new insights and directions. J. Pharmacol . Exp. Ther . 298 (2): 403-10. Sushmita P,Peter BR. 2011. The functional role of the alpha-1 andrenergic receptors in cerebral blood flow regulation. Indian J. Pharmacol . 43 (5): 502-506.