Thyroid hormones affect the membrane dipolar organization. Is it a general event in their non-genomic action?
The surface balance technique was employed to study the interactions of 3,5,3',5' tetraiodo L-thyronine, 3,5,3' triiodo L-thyronine, and 3,5-diiodothyronine with monomolecular phospholipid monolayers spread at the air-water interface. With this technique the insertion of thyroid hormones into egg yolk phosphatidylcholine was investigated. An increase of surface pressure and a substantial decrement in surface potential were observed after the injection of these hormones beneath a phospholipid monolayer. The negative dipole contribution upon hormone interaction opposes the well-known positive contribution of phospholipids. These effects correlated with iodo content of the thyroid molecule analogues 3,5,3',5' tetraiodo L-thyronine >3,5,3' triiodo L-thyronine >3,5-diiodothyronine. To our knowledge, these observations suggest a new and surprising effect of thyroid hormones on the regulation of transmembrane dipolar organization.
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Departamento de Bioquímica de la Nutrición, Instituto Superior de Investigaciones Biológicas, Chacabuco 461 (4000), San Miguel de Tucumán, Tucumán, Argentina.
Fidelio
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Farías
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D000327:Adsorption; D000388:Air; D008563:Membrane Lipids / Q000737:chemistry; D008564:Membrane Potentials; D008567:Membranes, Artificial; D010713:Phosphatidylcholines / Q000737:chemistry*; D013499:Surface Properties; D013963:Thyroid Hormones / Q000737:chemistry*; D014867:Water / Q000737:chemistry
D008563:Membrane Lipids; D008567:Membranes, Artificial; D010713:Phosphatidylcholines; D013963:Thyroid Hormones; D014867:Water