title: Effects of intraperitoneal administration of free and liposome-entrapped doxorubicin on rat peritoneal exudate cell populations.
abstract: In the present paper effects of i.p. treatment with free or liposome-entrapped doxorubicin (DXR) on rat peritoneal exudate cell (PEC) populations were examined. Two types of DXR-liposomes were used: one type consisting of egg-phosphatidylcholine/phosphatidylserine/cholesterol (molar ratio 10/1/4, mean size approx. 0.3 micron) and the other type of distearoylphosphatidylcholine/dipalmitoylglycerol/cholesterol (molar ratio 10/1/10, mean size approx. 0.8 micron). Dramatically fewer PEC could be recovered from rats given free DXR or DXR-liposomes i.p. (10 mg DXR/kg body weight) 24 h before sacrifice than from control rats. Also the ratio of leukocyte species was modified by treatment with DXR, in free or liposomal form; in both cases the relative number of macrophages tended to increase. HPLC determination of the amount of DXR associated with monolayers obtained by seeding PEC harvested after a single i.p. dose of free DXR or liposomal DXR suggests that peritoneal macrophages are not particularly active in endocytosing DXR-liposomes. It was observed that the peritoneal macrophages phagocytosed DXR-containing granules from degranulating mast cells after both i.p. treatment with free DXR and DXR-liposomes. Decreased yields of PEC following i.p. treatment with free or liposomal DXR as well as an involvement of mast cells in the processing of both free DXR and liposome-encapsulated DXR in the peritoneal cavity may have important consequences for approaches to i.p. chemotherapy.
authors.affiliation: Department of Pharmaceutics, Utrecht Institute for Pharmaceutical Sciences, Utrecht University, The Netherlands.
authors.forename: G
authors.initials: G
authors.lastname: Storm
authors.forename: P A
authors.initials: PA
authors.lastname: Steerenberg
authors.forename: M
authors.initials: M
authors.lastname: Van Borssum Waalkes
authors.forename: D J
authors.initials: DJ
authors.lastname: Crommelin
mesh_terms: D000818:Animals; D004317:Doxorubicin / Q000008:administration & dosage* / Q000494:pharmacology; D004337:Drug Carriers; D005122:Exudates and Transudates; D006801:Humans; D007274:Injections, Intraperitoneal; D008081:Liposomes; D017737:Macrophages, Peritoneal / Q000187:drug effects* / Q000276:immunology; D008407:Mast Cells / Q000187:drug effects* / Q000276:immunology; D051381:Rats
chemical_list: D004337:Drug Carriers; D008081:Liposomes; D004317:Doxorubicin