title: An immunohistochemical approach to differentiate hepatic lipidosis from hepatic phospholipidosis in rats.
abstract: Hepatocellular vacuolation can be a diagnostic challenge since cytoplasmic accumulations of various substances (lipid, water, phospholipids, glycogen, and plasma) can have a similar morphology. Cytoplasmic accumulation of phospholipids following administration of cationic amphiphilic drugs (CAD) can be particularly difficult to differentiate from nonphosphorylated lipid accumulations at the light microscopic level. Histochemical methods (Sudan Black, Oil Red-O, Nile Blue, etc.) can be used to identify both nonphosphorylated and/or phosphorylated lipid accumulations, but these techniques require non-paraffin-embedded tissue and are only moderately sensitive. Thus, electron microscopy is often utilized to achieve a definitive diagnosis based upon the characteristic morphologic features of phospholipid accumulations; however, this is a low throughput and labor intense procedure. In this report, we describe the use of immunohistochemical staining for LAMP-2 (a lysosome-associated protein) and adipophilin (a protein that forms the membrane around non-lysosomal lipid droplets) to differentiate phospholipidosis and lipidosis, respectively in the livers of rats. This staining procedure can be performed on formalin-fixed paraffin embedded tissues, is more sensitive than histochemistry, and easier to perform than ultrastructural evaluation.
authors.affiliation: Pfizer Global Research & Development, Ann Arbor, Michigan 48105, USA. leslie.obert@pfizer.com
authors.forename: Leslie A
authors.initials: LA
authors.lastname: Obert
authors.forename: Gregg P
authors.initials: GP
authors.lastname: Sobocinski
authors.forename: Walter F
authors.initials: WF
authors.lastname: Bobrowski
authors.forename: Alan L
authors.initials: AL
authors.lastname: Metz
authors.forename: Mark D
authors.initials: MD
authors.lastname: Rolsma
authors.forename: Douglas M
authors.initials: DM
authors.lastname: Altrogge
authors.forename: Robert W
authors.initials: RW
authors.lastname: Dunstan
mesh_terms: D000818:Animals; D003593:Cytoplasm / Q000378:metabolism; D003937:Diagnosis, Differential; D005260:Female; D007150:Immunohistochemistry; D008064:Lipidoses / Q000175:diagnosis*; D008099:Liver / Q000187:drug effects / Q000378:metabolism / Q000648:ultrastructure*; D052119:Lysosomal-Associated Membrane Protein 2 / Q000032:analysis*; D008565:Membrane Proteins; D010455:Peptides / Q000032:analysis*; D000070780:Perilipin-2; D010743:Phospholipids / Q000378:metabolism*; D051381:Rats; D017207:Rats, Sprague-Dawley; D014617:Vacuoles / Q000187:drug effects* / Q000648:ultrastructure
chemical_list: D052119:Lysosomal-Associated Membrane Protein 2; D008565:Membrane Proteins; D010455:Peptides; D000070780:Perilipin-2; D010743:Phospholipids; C000602984:Plin2 protein, rat