Browsing Pathways

3-Phosphoglycerate dehydrogenase deficiency is a disorder of L-serine biosynthesis that is characterized by congenital microcephaly, psychomotor retardation, and seizures.The disorder is caused by homozygous or compound heterozygous or homozygous mutation in the gene encoding phosphoglycerate dehydrogenase on chromosome 1p12. Defects in the gene lead to a decrease of Glycine and Serine.

4-Hydroxybutyric Aciduria/Succinic Semialdehyde Dehydrogenase Deficiency (SSADH; Gamma-hydroxybutyric acidemia) inhibits the formation of succinate from GABA. This deficiency results in urinary excretion of 4-hydroxybutyric acid. In vivo proton MR also indicates elevated GABA levels as compared with an age-matched control. Symptoms include ataxia, chorea or athetosis, motor retardation, seizures, macrocephaly and delayed or abnormal speech development.

5-Oxoprolinase deficiency, also called OPLAHD, is a rare inborn error of metabolism (IEM) and autosomal recessive disorder of glutathione metabolism caused by a defective 5-oxoprolinase. 5-Oxoprolinase catalyzes the conversion of 5-oxoproline into glutamate which is an important neurotransmitter. This disorder is characterized by a large accumulation of 5-oxoproline in the urine. Symptoms of the disorder include enterocolitis, mental retardation, kidney stone formation, and hypoglycemia. 5-Oxoprolinase deficiency has been reported in approximately 8 people.

5-Oxoprolinuria (5-Oxoprolinase deficiency) is a result of a defect in the gamma-glutamyl cycle due to either 5-oxoprolinase or glutathione synthetase deficiency. In the case of glutathione synthetase deficiency, the glycine is not incorporated into gamma-glutamylcysteine. In the case of 5-oxoprolinase, however, pyroglutamic acid accumulates. Symptoms include anemia, mental retardation, metabolic acidosis, respiratory distress and urolithiasis.

Abacavir (also known as Ziagen or Epzicom) is an antiviral agent that is used for treating HIV/AID. Cellular enzyme converts abacavir to its activate metabolite, carbovir triphosphate, for inhibiting HIV-1 reverse transcriptase (RT) by competing with dGTP, which is the natural substrate of RT. Without HIV-1 reverse transcriptase, complementary DNA (cDNA) could not be generated; therefore, viral DNA couldn't be completed.

Abciximab (also known as c7E3 Fab) is integrin (integrin alpha-IIb and integrin beta-3) receptor antagonist. Binding of abciximab to integrin receptor will block any large molecule to attach on the receptor, which will lead to block any associated signal transduction pathways.

Acebutolol (also known as Sectral or Prent) is a selective β1 adrenergic receptor antagonist (beta blocker), which can be used for treatment of high blood pressure (hypertension) and irregular heartbeats (arrhythmias). Acebutolol also has the ability to mild intrinsic sympathomimetic activity (ISA) with effective range of dosage. Adrenaline (also known as epinephrine) can activate β1 adrenergic receptor so that the heart rate and output will be increased. Renin is a hormone that generated from kidney, which could lead to constriction of blood vessels. Beta blockers could efficiently prohibit renin release.

Acenocoumarol (also known as Nitrowarfarin or Sinthrome) is an anticoagulant that inhibit the liver enzyme vitamin K reductase, which cause Vitamin K1 2,3-epoxide could not be catalyzed by vitamin K reductase to form vitamin KH2, the reduced form of vitamin K. Vitamin K-dependent coagulation factors (II, VII, IX, and X) requires its cofactor, vitamin K to facilitate the activation and gamma-carboxylation. Inhibition of vitamin K reductase results in reduced concentration of vitamin KH2, which will ultimately lead to decreased coagulability of the blood and reduced cleavage of fibrinogen into fibrin.

Acetaminophen (also named paracetamol or APAP) is not a Nonsteroidal anti-inflammatory drugs (NSAIDs). However, it still can be used to treat pain and fever. Acetaminophen can block prostaglandin synthesis by the action of inhibition of prostaglandin G/H synthase 1 and 2. Prostaglandin G/H synthase 1 and 2 catalyze the arachidonic acid to prostaglandin G2, and also catalyze prostaglandin G2 to prostaglandin H2 in the metabolism pathway. Decreased prostaglandin synthesis in many animal model's cell is caused by presence of acetaminophen.

Acetaminophen (APAP) is metabolized primarily in the liver. Glucuronidation is the main route, accounting for 45-55% of APAP metabolism, and is mediatied by UGT1A1, UGT1A6, UGT1A9, UGT2B15 in the liver and UGT1A10 in the gut. APAP can also by metabolized via sulfation, accounting for 30-35% of the metabolism. In the liver, this step is catalyzed by the sulfotransferases SULT1A1, SULT1A3, SULT1A4, SULT1E1 and SULT2A1. Moreover, APAP can also be activated to form the toxic N-acetyl-p-benzoquinone imine (NAPQI) under the mediation of CYP3A4, CYP2E1, CYP2D6 CYP1A2, CYP2E1 and CYP2A6.