1995 Volume 18 Issue 8 Pages 1084-1088
We investigated the effects of intranasal (i.n.) administration of recombinant human granulocyte colonystimulating factors (rhG-CSF) on the total count of leukocytes in peripheral blood (total blood leukocyte count) of rabbits with leukopenia who received cyclophosphamide (CPA). When CPA (30mg/kg per d) was administered intravenously, the total blood leukocyte count decreased to levels below 5000/μl approximately 4d after the initiation of CPA multiple dosing. The decreased level of the total blood leukocyte count was maintained throughout the period of CPA dosing. RhG-CSF was given once a day for 3 d in CPA-treated rabbits via i.n. administration of aqueous preparations containing rhG-CSF with or without α-cyclodextrin (α-CyD). The total blood leukocyte count increased from levels below 5000/μl to the normal physiological level following i.n. administration of rhG-CSF preparation and reduced the period of leukopenia induced by CPA. The coadministration of rhG-CSF and α-CyD was more effective in increasing the total blood leukocyte count. It is suggested that i.n. administration of rhG-CSF is promising for reducing the risk of cytotoxic chemotherapy (CPA)-induced leukopenia as an adverse side effect.