Prostaglandin transport.
Newly synthesized prostaglandins (PGs) efflux from cells by simple diffusion, driven by pH and the membrane potential. Metabolic clearance requires energy-dependent uptake across the plasma membrane, followed by cytoplasmic oxidation. Several PG carriers have been cloned and characterized. PGT is broadly expressed in cyclooxygenase (COX)-positive cells, appears to be a lactate/PG exchanger, and is coordinately regulated with COX. By analogy with neurotransmitter release and re-uptake, PGT may regulate pericellular PG levels via re-uptake. PGT may also direct PGs towards and/or away from specific sets of PG receptors. Other members of the OATP transporter family also catalyze PG uptake; these are variably expressed and have variable affinities for PGs. The OATs are alpha-ketoglutarate/organic anion exchangers that accept PGs; these probably represent the uptake step in renal and hepatic PG degradation and excretion. Finally, certain glutathione-conjugated leukotrienes and PGs are actively extruded from cells by the MRPs; these may also play a role in metabolic clearance of PGs.
Schuster
Victor L
VL
Departments of Medicine and Physiology & Biophysics, Albert Einstein College of Medicine, Bronx, NY 10461, USA. schuster@aecom.yu.edu
D000818:Animals; D017920:Antiporters / Q000235:genetics / Q000378:metabolism*; D001692:Biological Transport; D016764:Cell Polarity; D004268:DNA-Binding Proteins / Q000235:genetics / Q000378:metabolism*; D006801:Humans; D027361:Organic Anion Transporters; D011453:Prostaglandins / Q000378:metabolism*; D015398:Signal Transduction / Q000502:physiology
D017920:Antiporters; D004268:DNA-Binding Proteins; D027361:Organic Anion Transporters; D011453:Prostaglandins; C503526:SLCO2A1 protein, human