Pathways

Sonic hedgehog is a protein that in humans is encoded by the SHH ("sonic hedgehog") gene.[5] Both the gene and the protein may also be found notated alternatively as "Shh". Sonic hedgehog is one of three proteins in the mammalian signaling pathway family called hedgehog, the others being desert hedgehog (DHH) and Indian hedgehog (IHH). SHH is the best studied ligand of the hedgehog signaling pathway. It plays a key role in regulating vertebrate organogenesis, such as in the growth of digits on limbs and organization of the brain. Sonic hedgehog is the best established example of a morphogen as defined by Lewis Wolpert's French flag model—a molecule that diffuses to form a concentration gradient and has different effects on the cells of the developing embryo depending on its concentration. SHH remains important in the adult. It controls cell division of adult stem cells and has been implicated in the development of some cancers.

Sonidegib is a drug that is not metabolized by the human body as determined by current research and biotransformer analysis. Sonidegib passes through the liver and is then excreted from the body mainly through the kidney.

Sorafenib, marketed as Nexavar, is a drug for the treatment of advanced renal cell carcinoma (primary kidney cancer). It is an inhibitor of the RAF kinase protein and cell surface kinases PDGF-beta receptor, VEGF 2 and 3 receptor (many sources also say VEGFR 1), c-KIT receptor, and FLT-3 receptor. Overall, sorafenib targets the Raf/Mek/Erk pathway. The kinases that are targeting are involved in angiogenesis which reduces blood flow to the tumor and also for genetic transcription for cell proliferation and replication. Sorafenib's mechanism of action works by inhibiting the cell surface kinases, which blocks their signalling to RAF and AKT pathways which are responsible for cell proliferation. C-KIT and FLT-3 on tumor cells are inhibited causing their proliferation to stop and the PDGF and VEGF receptors on endothelial cells are inhibited to stop the growth of new blood vessels that bring blood flow to the tumor. Sorafenib also inhibits RAF1 which is a protein that regulates apoptosis of the cell. With RAF1 blocked, apoptosis is not regulated and can occur. Sorafenib is taken orally in a tablet for and enters the bloodstream through the GI tract to be delivered to the site of action.

Sorafenib is a drug that belongs to the antineoplastics drug class, which is the drug class relating to the treatment of cancer, specifically renal, hepatic and thyroid cancers. This drug works by stopping cancerous tumour progress and stopping therapy replication pf potentially malignant cells. It does this by inhibiting protein synthesis, as we will explore in the pathway. Sorafenib is administered orally, in a tablet form taken twice daily without food. Once ingested, sorafenib finds itself in the endoplasmic reticulum membrane , where it inhibits cytochrome P450 2B6, cytochrome P450 2C8, cytochrome P450 2C9 and UDP-glucuronosyltransferase 1-1. Sorafenib is also catalyzed, with the help uridine diphosphate glucuronic acid and the enzyme UDP-glucuronosyltransferase 1-9 to sorafenib b-D-glucuronide with a by-product of uridine 5’-diphosphate. Sorafenib also undergoes a transformation without the use of catalytic enzymes and becomes sorafenib metabolite M4 and subsequently becomes sorafenib metabolite M5. In another reaction, sorafenib teams up with water and oxygen, using cytochrome P450 3A4 to create sorafenib N-oxide and hydrogen peroxide. Sorafenib N-oxide then undergoes two more reactions, one where it becomes sorafenib N-oxide glucuronide, and another where it becomes sorafenib metabolite M1. Sorafenib metabolite M1 is also attached to another reaction, as sorafenib creates sorafenib metabolite M3, sorafenib metabolite M1 is also created from this metabolite.

Sotalol is a beta-adrenergic receptor antagonist, which is a treatment regimen for heart failure such as abnormal heart rhythms. Sotalol inhibits response to adrenergic stimuli by competitively blocking β1-adrenergic receptors within the myocardium and β2-adrenergic receptors within bronchial and vascular smooth muscle. The electrophysiologic effects of sotalol may be due to its selective inhibition of the rapidly activating component of the potassium channel involved in the repolarization of cardiac cells.

Sotalol is a methane sulfonanilide beta adrenergic antagonist used to treat life-threatening ventricular arrhythmias and to maintain sinus rhythm in atrial fibrillation or flutter. After being taken orally, it is absorbed into the blood through the GI tract and inhibits the beta 1 adrenergic receptor and the potassium voltage gated channel subfamily H member 2 protein on the cell membranes of cardiomyocytes. The beta 1 adrenergic receptor is responsible for Gs signalling and the production of cyclic adenosine monophosphate (cAMP) which activates the L-type calcium channel. The L-type calcium channel is responsible for the influx of calcium from extracellular environment into the cytosol of cardiomyocytes which activates ryanodine receptors to release calcium from the sarcoplasmic reticulum. Calcium is important for the contraction of heart muscle for myosin to and actin to power-stroke so the slower influx of calcium slows down the contractions of the heart lowering the heart rate. Sotalol is a competitive inhibitor of the rapid potassium channel. This inhibition lengthens the duration of action potentials and the refractory period in the atria and ventricles. The inhibition of rapid potassium channels is increases as heart rate decreases, which is why adverse effects like torsades de points is more likely to be seen at lower heart rates. The inhibition of potassium voltage gated channel subfamily H member 2 protein inhibits the efflux of potassium out of the cell during the repolarization phase of an action potential. This lengthens the QT interval of the heartbeat as well as prolonging the repolarization phase of action potentials. This regulates the heart rate and slows down any rapid heartrates. The action of sotalol on beta adrenergic receptors lengthens the sinus node cycle, conduction time through the atrioventricular node, refractory period, and duration of action potentials. Sotalol can be found under the brand names Betapace, Sorine, and Sotylize. Some side effects of using this drug may include feeling dizzy or sick, feeling tired, having diarrhoea or a headache.