title: Ethnic differences in pre-adipocyte intracellular lipid accumulation and alkaline phosphatase activity.
abstract: Alkaline phosphatase (ALP) increases lipid accumulation in human pre-adipocytes. This study was performed to assess whether ethnic differences in the prevalence of obesity in African and European females are related to differences in pre-adipocyte lipid accretion and ALP activity. Pre-adipocytes were isolated from 13 black and 14 white females. Adipogenesis was quantified using the lipid dye, Oil red O, whilst ALP activity was assayed in cell extracts on day zero and 12days after initiating adipogenesis. Lipid levels (OD units/mg protein) were lower in pre-adipocytes from white than black females on day 0 (0.36±0.05 versus 0.44±0.03, respectively; p<0.0005) and day 12 (1.18±0.14 versus 1.80±0.22, respectively; p<0.0005), as was ALP activity (mU/mg protein) on day zero (36.5±5.8 versus 136.4±10.9, respectively; p<0.0005) and day 12 (127±16 versus 278±27, respectively; p<0.0005). Treatment of pre-adipocytes with histidine, an ALP inhibitor, blocked lipid accumulation. Thus, lipid uptake is higher in pre-adipocytes isolated from black compared to white females which parallels the obesity prevalence rates in these population groups. The reason for higher fat accumulation in pre-adipocytes isolated from black females may be related to higher ALP activity.
authors.affiliation: Division of Chemical Pathology, National Health Laboratory Service, Tygerberg Hospital, University of Stellenbosch Medical School, South Africa. Electronic address: atali@sun.ac.za.
authors.forename: Aus T
authors.initials: AT
authors.lastname: Ali
authors.affiliation: Department of Chemical Pathology, National Health Laboratory Service, University of Witwatersrand Medical School, Parktown, South Africa.
authors.forename: George
authors.initials: G
authors.lastname: Chirambo
authors.affiliation: Department of Internal Medicine, University of Witwatersrand Medical School, Parktown, South Africa.
authors.forename: Clement
authors.initials: C
authors.lastname: Penny
authors.affiliation: Department of Chemical Pathology, National Health Laboratory Service, University of Witwatersrand Medical School, Parktown, South Africa.
authors.forename: Janice E
authors.initials: JE
authors.lastname: Paiker
authors.affiliation: Department of Surgery, University of Witwatersrand Medical School, Parktown, South Africa.
authors.forename: Faisel
authors.initials: F
authors.lastname: Ikram
authors.affiliation: Department of Surgery, University of Witwatersrand Medical School, Parktown, South Africa.
authors.forename: George
authors.initials: G
authors.lastname: Psaras
authors.affiliation: Department of Chemical Pathology, National Health Laboratory Service, University of Witwatersrand Medical School, Parktown, South Africa.
authors.forename: Nigel J
authors.initials: NJ
authors.lastname: Crowther
mesh_terms: D017667:Adipocytes / Q000187:drug effects / Q000201:enzymology* / Q000473:pathology; D050156:Adipogenesis / Q000187:drug effects; D000328:Adult; D000469:Alkaline Phosphatase / Q000037:antagonists & inhibitors / Q000378:metabolism*; D001391:Azo Compounds; D044383:Black People; D015992:Body Mass Index; D002454:Cell Differentiation; D005260:Female; D006639:Histidine / Q000494:pharmacology; D006801:Humans; D050356:Lipid Metabolism / Q000187:drug effects; D008875:Middle Aged; D009765:Obesity / Q000208:ethnology* / Q000378:metabolism* / Q000503:physiopathology; D015995:Prevalence; D061251:Primary Cell Culture; D013019:South Africa / Q000453:epidemiology; D044465:White People
chemical_list: D001391:Azo Compounds; D006639:Histidine; D000469:Alkaline Phosphatase; C011049:oil red O
keywords: Alkaline phosphatase; Histidine; Intracellular lipid accumulation