Human red cell membrane fluidity and calcium pump activity in normolipidaemic type II diabetic subjects.
Red cell membrane cholesterol, 1,6-diphenyl-1,3,5-hexatriene (DPH) and 1-[(4-trimethylammonium)phenyl]-6-phenyl-1,3,5-hexatriene (TMA-DPH) anisotropies and basal and calmodulin-stimulated calcium pump activities were compared in 16 normolipidaemic Type 2 (non-insulin-dependent) diabetic patients and 20 normolipidaemic control subjects using the Mann-Whitney U-test. Serum cholesterol, membrane cholesterol, and membrane DPH and TMA-DPH anisotropies were similar in the two groups but both basal and calmodulin-stimulated calcium pump activities were reduced in the diabetic group: basal activity (median (inter-quartile range), mumol mg-1 h-1) 1.66 (1.18-1.97) vs 2.09 (1.90-2.50), p < 0.005 and calmodulin-stimulated activity 4.19 (3.07-5.48) vs 5.53 (4.70-6.88), p < 0.006. Although there were no correlations between glycaemic control and membrane anisotropy and between glycaemic control and calcium pump activity, the reduction in calcium pump activity is most likely due to a direct effect of diabetes on the calcium pump protein itself.
Department of Medicine and Therapeutics, University of Leicester, UK.
S I
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Muzulu
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Bing
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Norman
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Burden
D000328:Adult; D001786:Blood Glucose / Q000032:analysis; D000252:Calcium-Transporting ATPases / Q000187:drug effects / Q000502:physiology*; D002147:Calmodulin / Q000494:pharmacology; D002784:Cholesterol / Q000032:analysis / Q000097:blood; D003924:Diabetes Mellitus, Type 2 / Q000097:blood* / Q000503:physiopathology*; D004161:Diphenylhexatriene / Q000031:analogs & derivatives / Q000032:analysis; D004910:Erythrocyte Membrane / Q000737:chemistry / Q000502:physiology* / Q000648:ultrastructure; D005260:Female; D005456:Fluorescent Dyes / Q000032:analysis; D006801:Humans; D008055:Lipids / Q000097:blood; D008297:Male; D008560:Membrane Fluidity / Q000502:physiology*; D008875:Middle Aged; D014280:Triglycerides / Q000097:blood
D001786:Blood Glucose; D002147:Calmodulin; D005456:Fluorescent Dyes; D008055:Lipids; D014280:Triglycerides; D004161:Diphenylhexatriene; C033628:1-(4-(trimethylamino)phenyl)-6-phenylhexa-1,3,5-triene; D002784:Cholesterol; D000252:Calcium-Transporting ATPases