Hypoxia directly increases serotonin transport by porcine pulmonary artery endothelial cell (PAEC) plasma membrane vesicles

Conference · Sun Feb 25 23:00:00 EST 1990 · FASEB Journal (Federation of American Societies for Experimental Biology); (United States)

OSTI ID:5610727

Bhat, G B; Block, E R ^[1]

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1. Univ. of Florida, Gainesville (United States)

Alterations in the physical state and composition of membrane lipids have been shown to interfere with a number of critical cellular and membrane functions including transmembrane transport. The authors have reported that hypoxia has profound effects upon the physical state and lipid composition of the PAEC plasma membrane bilayer and have suggested that this is responsible for increased serotonin uptake by these cells. In order to determine whether hypoxia has a direct effect on the plasma membrane transport of serotonin, they measured serotonin transport activity (1) in plasma membrane vesicles isolated from normoxic (20% O{sub 2}-5% CO{sub 2}) and hypoxic (0% O{sub 2}-5% CO{sub 2}) PAEC and (2) in PAEC plasma membrane vesicles that were exposed directly to normoxia or hypoxia. A 24-h exposure of PAEC to hypoxia resulted in a 40% increase in specific serotonin transport by plasma membrane vesicles derived from these cells. When plasma membrane vesicles were isolated and then directly exposed to normoxia or hypoxia for 1 h at 37C, a 31% increase in specific 5-HT transport was observed in hypoxic vesicles. Hypoxia did not alter the Km of serotonin transport (normoxia = 3.47 {mu}M versus hypoxia = 3.76 {mu}M) but markedly increased the maximal rate of transport (V{sup max}) (normoxia = 202.4 pmol/min/mg protein versus hypoxia = 317.9 pmol/min/mg protein). These results indicate that hypoxia increases serotonin transport in PAEC by a direct effect on the plasma membrane leading to an increase in the effective number of transporter molecules without alteration in transporter affinity for serotonin.

• OSTI ID: 5610727
• Report Number(s): CONF-9004153--
• Journal Information: FASEB Journal (Federation of American Societies for Experimental Biology); (United States), Journal Name: FASEB Journal (Federation of American Societies for Experimental Biology); (United States) Vol. 4:3; ISSN FAJOE; ISSN 0892-6638
• Country of Publication: United States
• Language: English

Related Subjects

560300* -- Chemicals Metabolism & Toxicology
63 RADIATION, THERMAL, AND OTHER ENVIRON. POLLUTANT EFFECTS ON LIVING ORGS. AND BIOL. MAT.
AMINES
ANIMAL TISSUES
ANIMALS
ANOXIA
AROMATICS
ARTERIES
AUTONOMIC NERVOUS SYSTEM AGENTS
AZAARENES
AZOLES
BIOLOGICAL EFFECTS
BLOOD VESSELS
BODY
CARDIOVASCULAR SYSTEM
DOMESTIC ANIMALS
DRUGS
ENDOTHELIUM
HETEROCYCLIC COMPOUNDS
HYDROXY COMPOUNDS
INDOLES
LIPIDS
LUNGS
MAMMALS
MEMBRANE TRANSPORT
NEUROREGULATORS
ORGANIC COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
ORGANS
PYRROLES
RADIOPROTECTIVE SUBSTANCES
RESPIRATORY SYSTEM
SEROTONIN
SWINE
SYMPATHOMIMETICS
TISSUES
TRYPTAMINES
VERTEBRATES