Browsing Pathways

Acetylsalicylic acid, also known as ASA or aspirin, belongs to a class of drugs known as non-steroidal anti-inflammatory drugs (NSAIDs). In addition to its anti-inflammatory properties, aspirin also acts as an analgesic, antipyretic and antithrombotic agent. Like most other NSAIDs, aspirin exerts its therapeutic effects by inhibiting prostaglandin G/H synthase 1 and 2, better known as cyclooxygenase-1 and -2 or simply COX-1 and -2. COX-1 and -2 catalyze the conversion of arachidonic acid to prostaglandin G2 and prostaglandin G2 to prostaglandin H2. Prostaglandin H2 is the precursor to a number of other prostaglandins, such as prostaglandin E2, involved in pain, fever and inflammation. The antipyretic properties of aspirin arise from inhibition of prostaglandin E2 synthesis in the preoptic region of the hypothalamus. Interference with adhesion and migration of granulocytes, polymorphonuclear leukocytes and macrophages at sites of inflammation account for its anti-inflammatory effects. The analgesic effects of aspirin likely occur due to peripheral action at the site of injury and possibly within the CNS. Aspirin is unique from other NSAIDs in that it is an irreversible COX inhibitor. Aspirin irreversibly acetylates a serine side chain of COX rendering the enzyme inactive. Enzyme activity can only be regained by production of more cyclooxygenase. This unique property of aspirin and its higher selectivity for COX-1 over COX-2 makes it an effective antiplatelet agent. Platelets contain COX-1, a key enzyme in the production thromboxane A2 (TXA2), which is a potent inducer of platelet aggregation. Since platelets lack the ability to make more enzyme, TXA2 production is inhibited for the lifetime of the platelet (approximately 8 – 12 days). Aspirin is commonly used at low doses to prevent cardiovascular events such as strokes and heart attacks. At higher doses, aspirin may be used as an analgesic, anti-inflammatory and antipyretic. Aspirin may cause gastric irritation and bleeding by inhibiting the synthesis of prostaglandins that enhance and maintain the protective gastric mucous layer.

Acrivastine is a second-generation alkylamine H1-antihistamine. H1-antihistamines interfere with the agonist action of histamine at the H1 receptor and are administered to attenuate inflammatory process in order to treat conditions such as allergic rhinitis, allergic conjunctivitis, and urticaria. Reducing the activity of the NF-κB immune response transcription factor through the phospholipase C and the phosphatidylinositol (PIP2) signalling pathways also decreases antigen presentation and the expression of pro-inflammatory cytokines, cell adhesion molecules, and chemotactic factors. Furthermore, lowering calcium ion concentration leads to increased mast cell stability which reduces further histamine release. First-generation antihistamines readily cross the blood-brain barrier and cause sedation and other adverse central nervous system (CNS) effects (e.g. nervousness and insomnia). Second-generation antihistamines are more selective for H1-receptors of the peripheral nervous system (PNS) and do not cross the blood-brain barrier. Consequently, these newer drugs elicit fewer adverse drug reactions.

cAMP dependent protein kinase is a signalling molecule, found in the nucleus and cytoplasm of cells. Cellular regulation and signal transduction in eukaryotic cells is driven by the phosphorylation of proteins. cAMP dependent protein kinase is created as an active enzyme, which is made possible by a fully phosphorylated activation loop.

G protein-coupled receptors sense stimuli outside the cell and transmit signals across the plasma membrane. Activation of protein kinase C (PKC) is one of the common signaling pathways. When a class of GPCRs are activated by a ligand, they activate Gq protein to bind GTP instead of GDP. After the Gq becomes active, it activates phospholipase C (PLC) to cleave the membrane lipid phosphatidylinositol 4,5-bisphosphate (PIP2) into inositol 1,4,5-trisphosphate (IP3) and diacyl glycerol (DAG). IP3 can bind Ins3P receptor to open calcium channel by diffusion from cytoplasm to ER. Activated calcium channel will release the calcium from ER into cytoplasm. Calcium can activate the kinase activity of PKC.

Acute intermittent porphyria (AIP), also called Swedish porphyria, is a rare inborn error of metabolism (IEM) and autosomal dominant disorder of heme biosynthesis caused by a defective HMBS gene. The HMBS gene codes for the protein hydroxymethylbilane synthase (porphobilinogen deaminase) which catalyzes the synthesis of porphobilinogen into hydroxymethylbilane. This disorder is characterized by a large accumulation of 5-aminolevulinic acid or porphobilinogen in both urine and serum. Most patients are asymptomatic between attacks. Symptoms of the disorder include abdominal pain, constipation, vomiting, hypertension, muscle weakness, seizures, delirium, coma, and depression. Treatment involves undertaking a high-carbohydrate diet and, during severe attacks, a glucose 10% infusion. It is estimated that AIP affects 5.9 per 1 000 000 people.

(10E)-11-(3,4-dimethyl-5-pentylfuran-2-yl)undec-10-enoylcarnitine is an acylcarnitine. The general role of acylcarnitines is to transport acyl-groups, organic acids and fatty acids, from the cytoplasm into the mitochondria so that they can be broken down to produce energy. As part of this process, (10E)-11-(3,4-dimethyl-5-pentylfuran-2-yl)undec-10-enoic acid is first transported into the cell via the long-chain fatty acid transport protein 1 (FATP1). Once inside the cell it undergoes a reaction to form an acyl-CoA derivative called (10E)-11-(3,4-dimethyl-5-pentylfuran-2-yl)undec-10-enoyl-CoA. This reaction is facilitated by the long-chain fatty-acid CoA ligase 1 protein, which adds a CoA moiety to appropriate acyl groups. Many acyl-CoA groups will then further react with other zwitterionic compounds such as carnitine (to form acylcarnitines) and amino acids (to form acyl amides). The carnitine needed to form acylcarnitines inside the cell is transported into the cell by the organic cation/carnitine transporter 2. In forming an acylcarnitine derivative, (10E)-11-(3,4-dimethyl-5-pentylfuran-2-yl)undec-10-enoyl-CoA reacts with L-carnitine to form (10E)-11-(3,4-dimethyl-5-pentylfuran-2-yl)undec-10-enoylcarnitine. This reaction is catalyzed by carnitine O-palmitoyltransferase. This enzyme resides in the mitochondrial outer membrane. While this reaction takes place, the (10E)-11-(3,4-dimethyl-5-pentylfuran-2-yl)undec-10-enoylcarnitine is moved into the mitochondrial intermembrane space. Following the reaction, the newly synthesized acylcarnitine is transported into the mitochondrial matrix by a mitochondrial carnitine/acylcarnitine carrier protein found in the mitochondrial inner membrane. Once in the matrix, (10E)-11-(3,4-dimethyl-5-pentylfuran-2-yl)undec-10-enoylcarnitine can react with the carnitine O-palmitoyltransferase 2 enzyme found in the mitochondrial inner membrane to once again form (10E)-11-(3,4-dimethyl-5-pentylfuran-2-yl)undec-10-enoyl-CoA and L-carnitine. (10E)-11-(3,4-dimethyl-5-pentylfuran-2-yl)undec-10-enoyl-CoA then enters into the mitochondrial beta-oxidation pathway to form aceytl-CoA. Acetyl-CoA can go on to enter the TCA cycle, or it can react with L-carnitine to form L-acetylcarnitine in a reaction catalyzed by Carnitine O-acetyltransferase. This reaction can occur in both directions, and L-acetylcarnitine and CoA can react to form acetyl-CoA and L-carnitine in certain circumstances. Finally, acetyl-CoA in the cytosol can be catalyzed by acetyl-CoA carboxylase 1 to form malonyl-CoA, which inhibits the action of carnitine O-palmitoyltransferase 1, thereby preventing (10E)-11-(3,4-dimethyl-5-pentylfuran-2-yl)undec-10-enoylcarnitine from forming and thereby preventing it from being transported into the mitochondria.

(10E)-11-(3,4-dimethyl-5-propylfuran-2-yl)undec-10-enoylcarnitine is an acylcarnitine. The general role of acylcarnitines is to transport acyl-groups, organic acids and fatty acids, from the cytoplasm into the mitochondria so that they can be broken down to produce energy. As part of this process, (10E)-11-(3,4-dimethyl-5-propylfuran-2-yl)undec-10-enoic acid is first transported into the cell via the long-chain fatty acid transport protein 1 (FATP1). Once inside the cell it undergoes a reaction to form an acyl-CoA derivative called (10E)-11-(3,4-dimethyl-5-propylfuran-2-yl)undec-10-enoyl-CoA. This reaction is facilitated by the long-chain fatty-acid CoA ligase 1 protein, which adds a CoA moiety to appropriate acyl groups. Many acyl-CoA groups will then further react with other zwitterionic compounds such as carnitine (to form acylcarnitines) and amino acids (to form acyl amides). The carnitine needed to form acylcarnitines inside the cell is transported into the cell by the organic cation/carnitine transporter 2. In forming an acylcarnitine derivative, (10E)-11-(3,4-dimethyl-5-propylfuran-2-yl)undec-10-enoyl-CoA reacts with L-carnitine to form (10E)-11-(3,4-dimethyl-5-propylfuran-2-yl)undec-10-enoylcarnitine. This reaction is catalyzed by carnitine O-palmitoyltransferase. This enzyme resides in the mitochondrial outer membrane. While this reaction takes place, the (10E)-11-(3,4-dimethyl-5-propylfuran-2-yl)undec-10-enoylcarnitine is moved into the mitochondrial intermembrane space. Following the reaction, the newly synthesized acylcarnitine is transported into the mitochondrial matrix by a mitochondrial carnitine/acylcarnitine carrier protein found in the mitochondrial inner membrane. Once in the matrix, (10E)-11-(3,4-dimethyl-5-propylfuran-2-yl)undec-10-enoylcarnitine can react with the carnitine O-palmitoyltransferase 2 enzyme found in the mitochondrial inner membrane to once again form (10E)-11-(3,4-dimethyl-5-propylfuran-2-yl)undec-10-enoyl-CoA and L-carnitine. (10E)-11-(3,4-dimethyl-5-propylfuran-2-yl)undec-10-enoyl-CoA then enters into the mitochondrial beta-oxidation pathway to form aceytl-CoA. Acetyl-CoA can go on to enter the TCA cycle, or it can react with L-carnitine to form L-acetylcarnitine in a reaction catalyzed by Carnitine O-acetyltransferase. This reaction can occur in both directions, and L-acetylcarnitine and CoA can react to form acetyl-CoA and L-carnitine in certain circumstances. Finally, acetyl-CoA in the cytosol can be catalyzed by acetyl-CoA carboxylase 1 to form malonyl-CoA, which inhibits the action of carnitine O-palmitoyltransferase 1, thereby preventing (10E)-11-(3,4-dimethyl-5-propylfuran-2-yl)undec-10-enoylcarnitine from forming and thereby preventing it from being transported into the mitochondria.

(10E)-8-Hydroxydodec-10-enoylcarnitine is an acylcarnitine. The general role of acylcarnitines is to transport acyl-groups, organic acids and fatty acids, from the cytoplasm into the mitochondria so that they can be broken down to produce energy. As part of this process, (10E)-8-hydroxydodec-10-enoic acid is first transported into the cell via the long-chain fatty acid transport protein 1 (FATP1). Once inside the cell it undergoes a reaction to form an acyl-CoA derivative called (10E)-8-hydroxydodec-10-enoyl-CoA. This reaction is facilitated by the long-chain fatty-acid CoA ligase 1 protein, which adds a CoA moiety to appropriate acyl groups. Many acyl-CoA groups will then further react with other zwitterionic compounds such as carnitine (to form acylcarnitines) and amino acids (to form acyl amides). The carnitine needed to form acylcarnitines inside the cell is transported into the cell by the organic cation/carnitine transporter 2. In forming an acylcarnitine derivative, (10E)-8-hydroxydodec-10-enoyl-CoA reacts with L-carnitine to form (10E)-8-hydroxydodec-10-enoylcarnitine. This reaction is catalyzed by carnitine O-palmitoyltransferase. This enzyme resides in the mitochondrial outer membrane. While this reaction takes place, the (10E)-8-hydroxydodec-10-enoylcarnitine is moved into the mitochondrial intermembrane space. Following the reaction, the newly synthesized acylcarnitine is transported into the mitochondrial matrix by a mitochondrial carnitine/acylcarnitine carrier protein found in the mitochondrial inner membrane. Once in the matrix, (10E)-8-hydroxydodec-10-enoylcarnitine can react with the carnitine O-palmitoyltransferase 2 enzyme found in the mitochondrial inner membrane to once again form (10E)-8-hydroxydodec-10-enoyl-CoA and L-carnitine. (10E)-8-Hydroxydodec-10-enoyl-CoA then enters into the mitochondrial beta-oxidation pathway to form aceytl-CoA. Acetyl-CoA can go on to enter the TCA cycle, or it can react with L-carnitine to form L-acetylcarnitine in a reaction catalyzed by Carnitine O-acetyltransferase. This reaction can occur in both directions, and L-acetylcarnitine and CoA can react to form acetyl-CoA and L-carnitine in certain circumstances. Finally, acetyl-CoA in the cytosol can be catalyzed by acetyl-CoA carboxylase 1 to form malonyl-CoA, which inhibits the action of carnitine O-palmitoyltransferase 1, thereby preventing (10E)-8-hydroxydodec-10-enoylcarnitine from forming and thereby preventing it from being transported into the mitochondria.

(10E,12E,14E)-16-hydroxy-9-oxooctadeca-10,12,14-trienoylcarnitine is an acylcarnitine. The general role of acylcarnitines is to transport acyl-groups, organic acids and fatty acids, from the cytoplasm into the mitochondria so that they can be broken down to produce energy. As part of this process, (10E,12E,14E)-16-hydroxy-9-oxooctadeca-10,12,14-trienoic acid is first transported into the cell via the long-chain fatty acid transport protein 1 (FATP1). Once inside the cell it undergoes a reaction to form an acyl-CoA derivative called (10E,12E,14E)-16-hydroxy-9-oxooctadeca-10,12,14-trienoyl-CoA. This reaction is facilitated by the long-chain fatty-acid CoA ligase 1 protein, which adds a CoA moiety to appropriate acyl groups. Many acyl-CoA groups will then further react with other zwitterionic compounds such as carnitine (to form acylcarnitines) and amino acids (to form acyl amides). The carnitine needed to form acylcarnitines inside the cell is transported into the cell by the organic cation/carnitine transporter 2. In forming an acylcarnitine derivative, (10E,12E,14E)-16-hydroxy-9-oxooctadeca-10,12,14-trienoyl-CoA reacts with L-carnitine to form (10E,12E,14E)-16-hydroxy-9-oxooctadeca-10,12,14-trienoylcarnitine. This reaction is catalyzed by carnitine O-palmitoyltransferase. This enzyme resides in the mitochondrial outer membrane. While this reaction takes place, the (10E,12E,14E)-16-hydroxy-9-oxooctadeca-10,12,14-trienoylcarnitine is moved into the mitochondrial intermembrane space. Following the reaction, the newly synthesized acylcarnitine is transported into the mitochondrial matrix by a mitochondrial carnitine/acylcarnitine carrier protein found in the mitochondrial inner membrane. Once in the matrix, (10E,12E,14E)-16-hydroxy-9-oxooctadeca-10,12,14-trienoylcarnitine can react with the carnitine O-palmitoyltransferase 2 enzyme found in the mitochondrial inner membrane to once again form (10E,12E,14E)-16-hydroxy-9-oxooctadeca-10,12,14-trienoyl-CoA and L-carnitine. (10E,12E,14E)-16-hydroxy-9-oxooctadeca-10,12,14-trienoyl-CoA then enters into the mitochondrial beta-oxidation pathway to form aceytl-CoA. Acetyl-CoA can go on to enter the TCA cycle, or it can react with L-carnitine to form L-acetylcarnitine in a reaction catalyzed by Carnitine O-acetyltransferase. This reaction can occur in both directions, and L-acetylcarnitine and CoA can react to form acetyl-CoA and L-carnitine in certain circumstances. Finally, acetyl-CoA in the cytosol can be catalyzed by acetyl-CoA carboxylase 1 to form malonyl-CoA, which inhibits the action of carnitine O-palmitoyltransferase 1, thereby preventing (10E,12E,14E)-16-hydroxy-9-oxooctadeca-10,12,14-trienoylcarnitine from forming and thereby preventing it from being transported into the mitochondria.

(10E,12E,14E)-9-hydroxy-16-oxooctadeca-10,12,14-trienoylcarnitine is an acylcarnitine. The general role of acylcarnitines is to transport acyl-groups, organic acids and fatty acids, from the cytoplasm into the mitochondria so that they can be broken down to produce energy. As part of this process, (10E,12E,14E)-9-hydroxy-16-oxooctadeca-10,12,14-trienoic acid is first transported into the cell via the long-chain fatty acid transport protein 1 (FATP1). Once inside the cell it undergoes a reaction to form an acyl-CoA derivative called (10E,12E,14E)-9-hydroxy-16-oxooctadeca-10,12,14-trienoyl-CoA. This reaction is facilitated by the long-chain fatty-acid CoA ligase 1 protein, which adds a CoA moiety to appropriate acyl groups. Many acyl-CoA groups will then further react with other zwitterionic compounds such as carnitine (to form acylcarnitines) and amino acids (to form acyl amides). The carnitine needed to form acylcarnitines inside the cell is transported into the cell by the organic cation/carnitine transporter 2. In forming an acylcarnitine derivative, (10E,12E,14E)-9-hydroxy-16-oxooctadeca-10,12,14-trienoyl-CoA reacts with L-carnitine to form (10E,12E,14E)-9-hydroxy-16-oxooctadeca-10,12,14-trienoylcarnitine. This reaction is catalyzed by carnitine O-palmitoyltransferase. This enzyme resides in the mitochondrial outer membrane. While this reaction takes place, the (10E,12E,14E)-9-hydroxy-16-oxooctadeca-10,12,14-trienoylcarnitine is moved into the mitochondrial intermembrane space. Following the reaction, the newly synthesized acylcarnitine is transported into the mitochondrial matrix by a mitochondrial carnitine/acylcarnitine carrier protein found in the mitochondrial inner membrane. Once in the matrix, (10E,12E,14E)-9-hydroxy-16-oxooctadeca-10,12,14-trienoylcarnitine can react with the carnitine O-palmitoyltransferase 2 enzyme found in the mitochondrial inner membrane to once again form (10E,12E,14E)-9-hydroxy-16-oxooctadeca-10,12,14-trienoyl-CoA and L-carnitine. (10E,12E,14E)-9-hydroxy-16-oxooctadeca-10,12,14-trienoyl-CoA then enters into the mitochondrial beta-oxidation pathway to form aceytl-CoA. Acetyl-CoA can go on to enter the TCA cycle, or it can react with L-carnitine to form L-acetylcarnitine in a reaction catalyzed by Carnitine O-acetyltransferase. This reaction can occur in both directions, and L-acetylcarnitine and CoA can react to form acetyl-CoA and L-carnitine in certain circumstances. Finally, acetyl-CoA in the cytosol can be catalyzed by acetyl-CoA carboxylase 1 to form malonyl-CoA, which inhibits the action of carnitine O-palmitoyltransferase 1, thereby preventing (10E,12E,14E)-9-hydroxy-16-oxooctadeca-10,12,14-trienoylcarnitine from forming and thereby preventing it from being transported into the mitochondria.