Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UNIPROT:P00790 (PGA)
 2,475 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Prostaglandins are analogs of the parent 20 carbon prostanoic acid. They are divided into 4 series: PGE; PGF; PGA; PGB, according to the presence of functionalities in the cyclopentane structure. Biosynthesis of prostaglandins were first independently reported by Bergstrom et.al. and van Dorp et.al. who showed that certain w-6-unsaturated fatty acids were biological precursors of prostaglandins. Later, various investigators reported the biosynthesis of prostaglandins of the different series. The 2 most widely used routes of prostaglandins synthesis are 1) the Corey cyclopentyl-lactone route, and 2) the bicyclohexane route. The synthesis is divided into 1) naturally occuring primary prostaglandins and 2) the prostaglandin analogs and derived prostaglandins. Because of the general instability of natural prostaglandins in the basic and acidic milieu, various preparations of prostaglandins and chemically stable dosage forms have been developed. Various methods used in analyzing prostaglandins include: 1) TLC; 2) GLC; 3) spectral methods; 4) radioimmunoassay; and 5) enzymatic assay. In vitro and in vivo studies on the metabolism and catabolism of various prostaglandins showed that they are rapidly metabolized in various animal systems and humans. The major routes for this metabolic transformation are: 1) oxidation of the secondary C15 hydroxy group; 2) reduction of the C13 double bond; 3) B-oxidation; 4) w-hydroxylation; and 5) w-oxidation. Prostaglandins produce a wide range of biological effects on animal and human systems (the reproductive; gastrointestinal; respiratory; and cardiovascular systems). The biological actions of prostaglandins on animal and human reproductive tissue vary depending on the particular prostaglandin studied and hormonal state of the tissue. Certain prostaglandins can decrease the tonus, frequency, and amplitude of spontaneous contractions of human uterine strips while other prostaglandins can cause contraction of isolated myometrial strips. Prostaglandins are widely used in labor induction; induction of therapeutic abortion; and fertility control. Prostaglandins have also been found to either increase or decrease cyclic AMP; inhibit ADP-induced platelet aggregation; lower blood pressure in animals; affect lipid and carbohydrate metabolism, and prevent adjuvant arthritis.
 ...
PMID:Prostaglandins. 456 72

1. The relationship between the chemical structure and the direct vasoactivity of different prostaglandins administered intra-arterially was studied in the dog hindlimb preparation.2. All of the prostaglandins studied, except PGF(1alpha) and PGF(2alpha), caused a dose related decrease in the femoral arterial perfusion pressure in dogs in which the femoral arterial blood flow was kept constant, indicating the direct vasodilator action of these prostaglandins.3. Among the prostaglandins studied, PGE(1) is the most potent vasodilator. Comparing the chemical structure and vasodilator action of PGE(1) with those of different prostaglandins, the following conclusions can be made:4. The formation of the Delta(5) double bond in PGE(1) causes no change in its vasodilator activity, whereas the saturation of the Delta(13) double bond of PGE(1) slightly reduces its activity.5. The alterations in the orientation and length of the carboxyl and alkyl side chains reduce markedly the vasodilator action of PGE- and PGA-compounds.6. The presence of a carbonyl group at C9 is the most important requirement for the potent vasodilator action of PGE(1). On the other hand, the presence and S-configuration of a hydroxyl group at C15 are essential for the intrinsic action at the receptor sites in the vascular smooth muscle, but may not be responsible for the vasodilator action.7. The esterification of PGE(1) or PGE(2) and a triple bond formation and the replacement of C7 with oxygen in prostaglandin appear to reduce or abolish their vasodilator action.
 ...
PMID:Relationship between the chemical structure of prostaglandins and their vasoactivities in dogs. 501 41