Changes in rat papilla microsomal membrane fluidity during development.
During maturation, rat renal papillary microsomes suffer a rearrangement in their fatty acid phospholipid composition. The most significant changes in total phospholipids are the increase in their content of the 20:4 and a decrease in the levels of 14:0, 16:0, 18:1, 22:6 and 20:3 fatty acids. The changes in total phospholipid fatty acid content are a reflection of the variations in the individual phospholipid composition. During this period, microsomal cholesterol, phospholipid, and protein concentrations present no variations. Steady state fluorescence anisotropy obtained by using TMA-DPH (see text) as a fluorescence probe denoted higher values for 70- versus 10-day-old microsomes. Using DPH as a probe, steady state fluorescence anisotropy was determined in whole microsomes, as well as in total lipid and phospholipid vesicles, from both 10- and 70-day-old papillary cells. No differences were detected in phospholipid and total lipid vesicles between days 10 and 70. On the other hand, 10-day-old microsomes appeared to be less fluid than adult microsomes. The results indicate that these structural changes in kidney membranes during development might affect protein-lipid interaction and, therefore, the activity of many membrane enzymes.
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Instituto de Química y Fisicoquímica Biológica (IQUIFIB), Departamento de Ciencias Biológicas, Facultad de Farmacia y Bioquímica, UBA-CONICET, Buenos Aires, Argentina.
Sterin-Speziale
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NB
D000818:Animals; D004161:Diphenylhexatriene / Q000031:analogs & derivatives; D005454:Fluorescence Polarization; D005456:Fluorescent Dyes; D007425:Intracellular Membranes / Q000502:physiology*; D007679:Kidney Medulla / Q000254:growth & development* / Q000648:ultrastructure*; D008560:Membrane Fluidity; D008861:Microsomes / Q000648:ultrastructure*; D051381:Rats; D017208:Rats, Wistar
D005456:Fluorescent Dyes; D004161:Diphenylhexatriene; C033628:1-(4-(trimethylamino)phenyl)-6-phenylhexa-1,3,5-triene