Lec 1 PDF - Organic Pharmaceutical Chemistry II - 17/9/2024

Prof. Dr. Rita Sabah Elias (Conference Hall) Lec 1 Organic pharmaceutical chemistry II Tuesday 17 /9/2024 (9.30 Am) No Lecture title Teachers 1 Cholinergic drugs and related agents Prof. Dr. Rita Sabah Elias 2...

Prof. Dr. Rita Sabah Elias (Conference Hall) Lec 1 Organic pharmaceutical chemistry II Tuesday 17 /9/2024 (9.30 Am) No Lecture title Teachers 1 Cholinergic drugs and related agents Prof. Dr. Rita Sabah Elias 2 Adrenergic agents Assist prof. Dr. Hiba Najeh 3 Analgesic agents Prof. Dr. Rita Sabah Elias 4 Central nervous system depressants l 5 Central nervous system stimulants 6 Steroidal and nonsteroidal hormones Assist prof. Dr. Hiba Najeh Reference Textbook of Organic medicinal and pharmaceutical chemistry By Wilson and Gisvold’s 1  Prof. Dr. Rita Sabah Elias (Conference Hall) Lec 1 Organic pharmaceutical chemistry II Tuesday 17 /9/2024 (9.30 Am) Cholinergic Drugs and Related Agents 2  Prof. Dr. Rita Sabah Elias (Conference Hall) Lec 1 Organic pharmaceutical chemistry II Tuesday 17 /9/2024 (9.30 Am) Acetylcholine (ACh):- The chemical transmitter at both pre and postganglionic synapses in the parasympathetic system is acetylcholine (Ach). Ach is also the neurotransmitter at sympathetic preganglionic synapses, some sympathetic postganglionic synapses, the neuromuscular junction (somatic nervous system), and at some sites in the CNS. Acetylcholine is the most widespread autonomic transmitter present in the body. Parasympathetic stimulation causes: - 1. Slowing down of the heart rate. 2. Lowering of blood pressure. 3. Constriction of the pupils. 4. Increased blood flow to the skin and viscera. 5. Peristalsis of the GI tract The Sympathetic Nervous System: - The neurotransmitter of the preganglionic sympathetic neurons is acetylcholine (ACh). It stimulates action potentials in the postganglionic neurons. The neurotransmitter released by the postganglionic neurons is noradrenaline (also called norepinephrine). The release of noradrenaline (sympathetic stimulation) causes: - 1. Stimulates heartbeat. 2. Raises blood pressure 3. Dilates the pupils 4. Dilates the trachea and bronchi 5. Stimulates the conversion of liver glycogen into glucose 6. Shunts blood away from the skin and viscera to the skeletal muscles, brain, and heart 7. Inhibits peristalsis in the GI tract. 8. Inhibits contraction of the bladder and rectum. 3  Prof. Dr. Rita Sabah Elias (Conference Hall) Lec 1 Organic pharmaceutical chemistry II Tuesday 17 /9/2024 (9.30 Am) Cholinergic agents: - are drugs and chemicals that act on cholinergic nerves or the tissues they innervate to either mimic or block the action of ACh. CHOLINERGIC RECEPTORS Acetylcholine acts on two different classes of receptors-nicotinic receptors and muscarinic receptors (widely distributed within both peripheral and central nervous systems). Nicotinic Receptors:- (ionotropic receptor, ligand gate ion channel) when stimulated by their neurotransmitter they themselves become an ion channel. 4  Prof. Dr. Rita Sabah Elias (Conference Hall) Lec 1 Organic pharmaceutical chemistry II Tuesday 17 /9/2024 (9.30 Am) These ion channels are made of five subunits polypeptide chains (pentameric structures), of which two appear to be identical, 2α, β, γ, and δ (ε) and they are arranged symmetrically around a central pore through which ions travel when opened. Each α chain contains a negatively charged binding site for the quaternary ammonium group of ACh. The receptor appears to exist as a dimer of the two five-subunit polypeptide chain monomers linked through a disulfide bond between δ chains. When stimulated by either Ach or nicotine. This is going to cause a conformational change in the shape of the ion channel, which is going to open the central pore and rapid flow of cations resulting in depolarization and generation of action potential NICOTINIC RECEPTOR SUBTYPES 5  Prof. Dr. Rita Sabah Elias (Conference Hall) Lec 1 Organic pharmaceutical chemistry II Tuesday 17 /9/2024 (9.30 Am) Muscarinic Receptors: - play an essential role in regulating the functions of organs innervated by the autonomic nervous system to maintain homeostasis of the organism. Muscarinic receptors mediate their effects by activating guanosine triphosphate (GTP)-binding proteins (G- protein) coupled receptor. Muscarinic Receptors subtypes Subtypes of muscarinic receptors are located in the CNS and peripheral nervous system 6  Prof. Dr. Rita Sabah Elias (Conference Hall) Lec 1 Organic pharmaceutical chemistry II Tuesday 17 /9/2024 (9.30 Am) M2 receptor:- are also called cardiac muscarinic receptors because they are located in the atria and conducting tissue of the heart. M4 Receptors: - M4 receptors, like M2 receptors and M5 Receptors: - like M1 and M3 receptors 7