Pathways

Very long-chain acyl-CoA dehydrogenase deficiency (VLCAD), also called ACADL and VLCAD, is a rare inborn error of metabolism (IEM) and autosomal recessive disorder, which is caused by a defective very long-chain specific acyl-CoA dehydrogenase. Very long-chain specific acyl-CoA dehydrogenase breakdown certain fats to energy. This disorder is characterized by a large accumulation of fatty acids such as L-Palmitoylcarnitine in the mitochondria. Symptoms of the disorder include muscle weakness, lethargy (lack of energy) and hypoglycemia (low blood sugar). Treatment with diet modifications such as consuming supplemental calories is suggested. It is estimated that very long-chain acyl-CoA dehydrogenase deficiency affects 1 in 40,000 to 120,000 individuals.

Very long-chain acyl-CoA dehydrogenase deficiency (VLCAD), also called ACADL and VLCAD, is a rare inborn error of metabolism (IEM) and autosomal recessive disorder, which is caused by a defective very long-chain specific acyl-CoA dehydrogenase. Very long-chain specific acyl-CoA dehydrogenase breakdown certain fats to energy. This disorder is characterized by a large accumulation of fatty acids such as L-Palmitoylcarnitine in the mitochondria. Symptoms of the disorder include muscle weakness, lethargy (lack of energy) and hypoglycemia (low blood sugar). Treatment with diet modifications such as consuming supplemental calories is suggested. It is estimated that very long-chain acyl-CoA dehydrogenase deficiency affects 1 in 40,000 to 120,000 individuals.

Vibegron is a beta-3 adrenergic agonist the treatment of overactive bladder (OAB) with symptoms of urge urinary incontinence, urgency, and urinary frequency in adults. It can be found under the brand name Gemtesa and it relaxes the detrusor smooth muscle of the bladder, thereby increasing bladder capacity. β3AR is stimulated and undergoes a conformation change and activates adenylyl cyclases (AC), which promotes the formation of cyclic adenosine monophosphate (cAMP). Increased intracellular cAMP concentration leads to the activation of cAMP-dependent protein kinase A (PKA), which subsequently phosphorylates myosin light chains that are responsible for inhibiting the interaction of actin with myosin dependent on calcium – calmodulin complex. Once vibegron is administered and it binds to the beta-3 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 bladder causes the bladder to expand to relax, making the sense of urgency for urination lesser. Some side effects of using vibegron may include headache, nausea, fever, and diarrhea.

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

Vidarabine is an antiviral agent used to treat various viral infections. It has some antineoplastic properties and has broad spectrum activity against DNA viruses in cell cultures and significant antiviral activity against infections caused by a variety of viruses such as the herpes viruses, the vaccinia VIRUS and varicella zoster virus. Vidarabine stops replication of herpes viral DNA by either competitive inhibition of viral DNA polymerase, and consequently or incorporation into and termination of the growing viral DNA chain. Vidarabine is sequentially phosphorylated by kinases to the triphosphate ara-ATP, which is the active form of vidarabine that acts as both an inhibitor and a substrate of viral DNA polymerase.Ara-ATP inhibits the activity of DNA polymerase by competing with its substrate dATP. Ara-ATP also gets incorporated into viral DNA, but since it lacks the 3'-OH group which is needed to form the 5′ to 3′ phosphodiester linkage essential for DNA chain elongation, this causes DNA chain termination, preventing the growth of viral DNA.

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