Pathways

Procaterol is a beta-2 adrenergic agonist that is used as a bronchodilator. It is a long acting and potent drug that can be taken orally or through inhalation for the treatment of asthma and COPD. The purpose of this drug is to increase the bronchial air flow via G protein signalling upon activation of the beta-2 adrenergic receptor in bronchial smooth muscle cells. Once procaterol is administered and it binds to the beta-2 adrenergic receptor, the G protein signalling cascade begins. The alpha and beta/gamma subunits of the G protein separate and GDP is replaced with GTP on the alpha subunit. This alpha subunit then activates adenylyl cyclase which converts ATP to cAMP. cAMP then activates protein kinase A (PKA) which in turn phosphorylates targets and inhibits MLCK through decreased calcium levels causing muscle relaxation. PKA can phosphorylate certain Gq-coupled receptors as well as phospholipase C (PLC) and thereby inhibit G protein-coupled receptor (GPCR) -PLC-mediated phosphoinositide (PI) generation, and thus calcium flux. PKA phosphorylates the inositol 1,4,5-trisphosphate (IP3) receptor to reduce its affinity for IP3 and further limit calcium mobilization. PKA phosphorylates myosin light chain kinase (MLCK) and decreases its affinity to calcium calmodulin, thus reducing activity and myosin light chain (MLC) phosphorylation. Inhibits the phosphorylation of myosin. PKA also phosphorylates KCa++ channels in ASM, increasing their open-state probability (and therefore K+ efflux) and promoting hyperpolarization. Since myosine light chain kinase is not activated, Serine/threonine-protein phosphatase continues to dephosphorylate myosin LC-P, and more cannot be synthesized so myosin remains unbound from actin causing muscle relaxation. This relaxation of the smooth muscles in the lungs causes the bronchial airways to relax which causes bronchodialation, making it easier to breathe. Procaterol is administered via Some side effects of using procaterol may include tinnitus, nausea, vomiting, dry mouth, and fatigue.

Celiprolol is a selective beta-1 adrenergic receptor antagonist and a beta-2 adrenergic receptor partial agonist that is used for the management of hypertension and angina pectoris. The beta-2 adrenergic receptor agonist activity is attributed to this effect, by causing vasodilation and lowering the blood pressure through relaxation of vascular smooth muscles via the formation of cAMP. It lowers blood pressure in hypertensive patients at rest and on exercise. The effects on heart rate and cardiac output are dependent on the pre-existing background level of sympathetic tone. Under conditions of stress such as exercise, celiprolol attenuates chronotropic and inotropic responses to sympathetic stimulation. However, at rest minimal impairment of cardiac function is seen. Once celiprolol is administered and it binds to the beta-2 adrenergic receptor, the G protein signalling cascade begins. The alpha and beta/gamma subunits of the G protein separate and GDP is replaced with GTP on the alpha subunit. This alpha subunit then activates adenylyl cyclase which converts ATP to cAMP. cAMP then activates protein kinase A (PKA) which in turn phosphorylates targets and inhibits MLCK through decreased calcium levels causing muscle relaxation. PKA can phosphorylate certain Gq-coupled receptors as well as phospholipase C (PLC) and thereby inhibit G protein-coupled receptor (GPCR) -PLC-mediated phosphoinositide (PI) generation, and thus calcium flux. PKA phosphorylates the inositol 1,4,5-trisphosphate (IP3) receptor to reduce its affinity for IP3 and further limit calcium mobilization. PKA phosphorylates myosin light chain kinase (MLCK) and decreases its affinity to calcium calmodulin, thus reducing activity and myosin light chain (MLC) phosphorylation. PKA also phosphorylates KCa++ channels in ASM, increasing their open-state probability (and therefore K+ efflux) and promoting hyperpolarization. Since myosine light chain kinase is not activated, Serine/threonine-protein phosphatase continues to dephosphorylate myosin LC-P, and more cannot be synthesized so myosin remains unbound from actin causing muscle relaxation. This muscle relaxation of the vascular smooth muscle causes the blood vessels to dilate and allows for the lowering of blood pressure. Some side effects of using celiprolol can include headache, hot flushes, asthenia, and dizziness.

Trolamine salicylate is a nonsteroidal anti-inflammatory agent (NSAID) used for the temporary relief of some minor aches and pains of the muscles and joints associated with backache, lumbago, strains, bruises, sprains, and arthritic or rheumatic pain, pain of tendons and ligaments. This drug is used as a topical analgesic. It targets the prostaglandin G/H synthase-1 (COX-1) and prostaglandin G/H synthase-2 (COX-2) in the cyclooxygenase pathway. The cyclooxygenase pathway begins in the cytosol with phospholipids being converted into arachidonic acid by the action of phospholipase A2. The rest of the pathway occurs on the endoplasmic reticulum membrane, where prostaglandin G/H synthase 1 & 2 convert arachidonic acid into prostaglandin H2. Prostaglandin H2 can either be converted into thromboxane A2 via thromboxane A synthase, prostacyclin/prostaglandin I2 via prostacyclin synthase, or prostaglandin E2 via prostaglandin E synthase. COX-2 is an inducible enzyme, and during inflammation, it is responsible for prostaglandin synthesis. It leads to the formation of prostaglandin E2 which is responsible for contributing to the inflammatory response by activating immune cells and for increasing pain sensation by acting on pain fibers. Trolamine salicylate inhibits the action of COX-1 and COX-2 on the endoplasmic reticulum membrane. This reduces the formation of prostaglandin H2 and therefore, prostaglandin E2 (PGE2). The low concentration of prostaglandin E2 attenuates the effect it has on stimulating immune cells and pain fibers, consequently reducing inflammation and pain.

Clenbuterol is a beta-2 adrenergic agonist used as a bronchodilator. This drug is taken orally and is used for the treatment of asthma, bronchitis, and COPD. It exerts its effect through activation of adenylyl cyclase leading to muscle relaxation of the bronchial smooth muscles via G protein signalling. Once clenbuterol is administered and it binds to the beta-2 adrenergic receptor, the G protein signalling cascade begins. The alpha and beta/gamma subunits of the G protein separate and GDP is replaced with GTP on the alpha subunit. This alpha subunit then activates adenylyl cyclase which converts ATP to cAMP. cAMP then activates protein kinase A (PKA) which in turn phosphorylates targets and inhibits MLCK through decreased calcium levels causing muscle relaxation. PKA can phosphorylate certain Gq-coupled receptors as well as phospholipase C (PLC) and thereby inhibit G protein-coupled receptor (GPCR) -PLC-mediated phosphoinositide (PI) generation, and thus calcium flux. PKA phosphorylates the inositol 1,4,5-trisphosphate (IP3) receptor to reduce its affinity for IP3 and further limit calcium mobilization. PKA phosphorylates myosin light chain kinase (MLCK) and decreases its affinity to calcium calmodulin, thus reducing activity and myosin light chain (MLC) phosphorylation. PKA also phosphorylates KCa++ channels in ASM, increasing their open-state probability (and therefore K+ efflux) and promoting hyperpolarization. Since myosine light chain kinase is not activated, Serine/threonine-protein phosphatase continues to dephosphorylate myosin LC-P, and more cannot be synthesized so myosin remains unbound from actin causing muscle relaxation. This relaxation of the smooth muscles in the lungs causes the bronchial airways to relax which causes bronchodialation, making it easier to breathe. Some side effects of using clenbuterol may include anxiety, shaking, and heart dysfunction.

Dipivefrin is a prodrug of epinephrine used in ophthalmic solutions to reduce intraocular pressure in chronic open-angle glaucoma. It is available as ophthalmic solution (eye drops). Dipivefrin is a prodrug with little or no pharmacologically activity until it is hydrolyzed into epinephrine inside the human eye. The liberated epinephrine, an adrenergic agonist, appears to exert its action by stimulating α -and/or β2-adrenergic receptors, leading to a decrease in aqueous production and an enhancement of outflow facility. The dipivefrin prodrug delivery system is a more efficient way of delivering the therapeutic effects of epinephrine, with fewer side effects than are associated with conventional epinephrine therapy. Epinephrine reduces the amount of aqueous humour fluids, effectively reducing the intraocular pressure, by activating the alpha-2 adrenergic receptors. Aqueous production decreases when ciliary blood flow is reduced by lowering the ocular perfusion pressure, and hypothesized that drug-induced reduction of ciliary blood flow would also decrease aqueous production. Stimulation of α2 receptors by reduces production by decreasing cAMP. The alpha-2 receptor acts as an allosteric inhibitor through Gi function, leading to an inhibition of adenylyl cyclase, decreasing the formation of intracellular cAMP leading to muscle contraction in smooth muscle. This muscle contraction of the ciliary vessel smooth muscle causes the blood vessels of the eye to contract and reduce aqueous humour productiion. Some side effects of dipivefrin may include irregular heartbeat, increased blood pressure, pain or swelling of the eye, skin rash, and eye watering.

Loxoprofen is a nonsteroidal anti-inflammatory agent used to treat pain and inflammation in musculoskeletal conditions and joint disorders. This drug is also an antipyretic and anti-inflammatory medication. Since loxoprofen is a prodrug, it is rapidly metabolized by the carbonyl reductase in the liver to its trans-alcohol form, which is a non-selective inhibitor of cyclooxygenase. This trans-alcohol form targets the prostaglandin G/H synthase-1 (COX-1) and prostaglandin G/H synthase-2 (COX-2) in the cyclooxygenase pathway. The cyclooxygenase pathway begins in the cytosol with phospholipids being converted into arachidonic acid by the action of phospholipase A2. The rest of the pathway occurs on the endoplasmic reticulum membrane, where prostaglandin G/H synthase 1 & 2 convert arachidonic acid into prostaglandin H2. Prostaglandin H2 can either be converted into thromboxane A2 via thromboxane A synthase, prostacyclin/prostaglandin I2 via prostacyclin synthase, or prostaglandin E2 via prostaglandin E synthase. COX-2 is an inducible enzyme, and during inflammation, it is responsible for prostaglandin synthesis. It leads to the formation of prostaglandin E2 which is responsible for contributing to the inflammatory response by activating immune cells and for increasing pain sensation by acting on pain fibers. Salsalate inhibits the action of COX-1 and COX-2 on the endoplasmic reticulum membrane. This reduces the formation of prostaglandin H2 and therefore, prostaglandin E2 (PGE2). The low concentration of prostaglandin E2 attenuates the effect it has on stimulating immune cells and pain fibers, consequently reducing inflammation and pain. Loxoprofen is administered as an oral tablet.

Fenoterol is a short acting beta-2 adrenergic receptor agonist that is used as a bronchodilator. This drug causes the relaxation of bronchial smooth muscle allowing for its use for the treatment of asthma. The result of taking this drug is relaxation of the bronchial smooth muscles causing bronchodilaton and increased airflow. Once fenoterol is administered and it binds to the beta-2 adrenergic receptor, the G protein signalling cascade begins. The alpha and beta/gamma subunits of the G protein separate and GDP is replaced with GTP on the alpha subunit. This alpha subunit then activates adenylyl cyclase which converts ATP to cAMP. cAMP then activates protein kinase A (PKA) which in turn phosphorylates targets and inhibits MLCK through decreased calcium levels causing muscle relaxation. PKA can phosphorylate certain Gq-coupled receptors as well as phospholipase C (PLC) and thereby inhibit G protein-coupled receptor (GPCR) -PLC-mediated phosphoinositide (PI) generation, and thus calcium flux. PKA phosphorylates the inositol 1,4,5-trisphosphate (IP3) receptor to reduce its affinity for IP3 and further limit calcium mobilization. PKA phosphorylates myosin light chain kinase (MLCK) and decreases its affinity to calcium calmodulin, thus reducing activity and myosin light chain (MLC) phosphorylation. PKA also phosphorylates KCa++ channels in ASM, increasing their open-state probability (and therefore K+ efflux) and promoting hyperpolarization. Since myosine light chain kinase is not activated, Serine/threonine-protein phosphatase continues to dephosphorylate myosin LC-P, and more cannot be synthesized so myosin remains unbound from actin causing muscle relaxation. This relaxation of the smooth muscles in the lungs causes the bronchial airways to relax which causes bronchodilation, making it easier to breathe. Some side effects of using fenoterol may include chest pain, dizziness, dry mouth, fatigue, and headache.

Isoetharine is a selective beta-2 adrenergic agonist used as a bronchodilator. This is a fast acting drug offering relief of bronchospasm for the treatment of emphysema, bronchitis, and asthma. Isoetharine is inhaled and acts by activating adenylyl cyclase to increase cAMP levels and subsequently relaxes bronchial smooth muscle. The result of taking this drug is relaxation of the bronchial smooth muscles causing bronchodilaton and increased airflow. Once isoetharine is administered and it binds to the beta-2 adrenergic receptor, the G protein signalling cascade begins. The alpha and beta/gamma subunits of the G protein separate and GDP is replaced with GTP on the alpha subunit. This alpha subunit then activates adenylyl cyclase which converts ATP to cAMP. cAMP then activates protein kinase A (PKA) which in turn phosphorylates targets and inhibits MLCK through decreased calcium levels causing muscle relaxation. PKA can phosphorylate certain Gq-coupled receptors as well as phospholipase C (PLC) and thereby inhibit G protein-coupled receptor (GPCR) -PLC-mediated phosphoinositide (PI) generation, and thus calcium flux. PKA phosphorylates the inositol 1,4,5-trisphosphate (IP3) receptor to reduce its affinity for IP3 and further limit calcium mobilization. PKA phosphorylates myosin light chain kinase (MLCK) and decreases its affinity to calcium calmodulin, thus reducing activity and myosin light chain (MLC) phosphorylation. PKA also phosphorylates KCa++ channels in ASM, increasing their open-state probability (and therefore K+ efflux) and promoting hyperpolarization. Since myosine light chain kinase is not activated, Serine/threonine-protein phosphatase continues to dephosphorylate myosin LC-P, and more cannot be synthesized so myosin remains unbound from actin causing muscle relaxation. This relaxation of the smooth muscles in the lungs causes the bronchial airways to relax which causes bronchodilation, making it easier to breathe. The result of taking this drug is relaxation of the bronchial smooth muscles causing bronchodilaton and increased airflow. Isoetharine has also been shown to stimulate beta-1 receptors in some patients, causing cardiac and CNS side effects. Some side effects of using isoetharine may include dizziness, nervousness, tremor, and headache.

Pirbuterol is a beta-2 adrenergic agonist that has a preferential effect. It is a short acting, inhaled drug that causes bronchial smooth muscle relaxation through stimulation of adenylyl cyclase. It is used as a bronchodilator for the treatment of asthma and relief from bronchospasm. The result of taking this drug is relaxation of the bronchial smooth muscles causing bronchodilaton and increased airflow. Once pirbuterol is administered and it binds to the beta-2 adrenergic receptor, the G protein signalling cascade begins. The alpha and beta/gamma subunits of the G protein separate and GDP is replaced with GTP on the alpha subunit. This alpha subunit then activates adenylyl cyclase which converts ATP to cAMP. cAMP then activates protein kinase A (PKA) which in turn phosphorylates targets and inhibits MLCK through decreased calcium levels causing muscle relaxation. PKA can phosphorylate certain Gq-coupled receptors as well as phospholipase C (PLC) and thereby inhibit G protein-coupled receptor (GPCR) -PLC-mediated phosphoinositide (PI) generation, and thus calcium flux. PKA phosphorylates the inositol 1,4,5-trisphosphate (IP3) receptor to reduce its affinity for IP3 and further limit calcium mobilization. PKA phosphorylates myosin light chain kinase (MLCK) and decreases its affinity to calcium calmodulin, thus reducing activity and myosin light chain (MLC) phosphorylation. PKA also phosphorylates KCa++ channels in ASM, increasing their open-state probability (and therefore K+ efflux) and promoting hyperpolarization. Since myosine light chain kinase is not activated, Serine/threonine-protein phosphatase continues to dephosphorylate myosin LC-P, and more cannot be synthesized so myosin remains unbound from actin causing muscle relaxation. This relaxation of the smooth muscles in the lungs causes the bronchial airways to relax which causes bronchodilation, making it easier to breathe. Pirbuterol is administered via respiratory inhalation. Some side effects of using pibuterol may include tremor, nervousness, dizziness, weakness, headache, and upset stomach.

Vilanterol is a long acting beta-2 adrenergic agonist. It can be found under the brand names Anoro, Anoro Ellipta, Breo Ellipta, and Trelegy Ellipta. It has a 24 hour activity and is used as a bronchodilator for the treatment of COPD and asthma. This drug causes the relaxation of bronchial smooth muscle through stimulation of adenylyl cyclase. The result of taking this drug is relaxation of the bronchial smooth muscles causing bronchodilaton and increased airflow. Once vilanterol is administered and it binds to the beta-2 adrenergic receptor, the G protein signalling cascade begins. The alpha and beta/gamma subunits of the G protein separate and GDP is replaced with GTP on the alpha subunit. This alpha subunit then activates adenylyl cyclase which converts ATP to cAMP. cAMP then activates protein kinase A (PKA) which in turn phosphorylates targets and inhibits MLCK through decreased calcium levels causing muscle relaxation. PKA can phosphorylate certain Gq-coupled receptors as well as phospholipase C (PLC) and thereby inhibit G protein-coupled receptor (GPCR) -PLC-mediated phosphoinositide (PI) generation, and thus calcium flux. PKA phosphorylates the inositol 1,4,5-trisphosphate (IP3) receptor to reduce its affinity for IP3 and further limit calcium mobilization. PKA phosphorylates myosin light chain kinase (MLCK) and decreases its affinity to calcium calmodulin, thus reducing activity and myosin light chain (MLC) phosphorylation. PKA also phosphorylates KCa++ channels in ASM, increasing their open-state probability (and therefore K+ efflux) and promoting hyperpolarization. Since myosine light chain kinase is not activated, Serine/threonine-protein phosphatase continues to dephosphorylate myosin LC-P, and more cannot be synthesized so myosin remains unbound from actin causing muscle relaxation. This relaxation of the smooth muscles in the lungs causes the bronchial airways to relax which causes bronchodilation, making it easier to breathe. Some side effects of taking vilanterol may include body aches, chills, cough, fever, and headache.