title: Phenylhydrazine-induced leukocytosis in the rat.
abstract: Rats were injected with phenylhydrazine (PHZ) for periods of up to 6 months, during which time a marked leukocytosis was induced. The highest leukocyte counts occurred within 4-5 days following injection. An initial injection of 4 mg/100 gm body weight evoked a mean total leukocyte count of 129 X 10(3) cells/microliter. Successive weekly injections of 2 mg/100 gm resulted in a mean total leukocyte count of 70 X 10(3) cells/microliter compared to a mean total leukocyte count of 12.5 X 10(3) cells/microliter in saline-injected rats. Lymphocytes and monocytes accounted for approximately 75% of the total cell counts in both the PHZ-treated and control rats. The presence of increased numbers of mononuclear cells was confirmed by Percoll gradient separation and by phase-contrast microscopy. Although a leukocytosis was evident when using the automated Coulter electronic cell counter, it was not discernible when blood samples were counted manually in a hemocytometer by light microscopy. Histological examination of the thymus, lymph nodes, and spleen of the PHZ-treated rats indicated that lymphocytes and monocytes were mobilized from these sites. Lymphocyte depletion was evident, and germinal centers were found in all these lymphoid organs, indicating that PHZ induced a lymphopoietic response. A possible autoimmune etiology for PHZ-induced red blood cell destruction is discussed.
authors.forename: B S
authors.initials: BS
authors.lastname: Dornfest
authors.forename: D M
authors.initials: DM
authors.lastname: Lapin
authors.forename: B A
authors.initials: BA
authors.lastname: Naughton
authors.forename: S
authors.initials: S
authors.lastname: Adu
authors.forename: L
authors.initials: L
authors.lastname: Korn
authors.forename: A S
authors.initials: AS
authors.lastname: Gordon
mesh_terms: D000818:Animals; D002469:Cell Separation; D004305:Dose-Response Relationship, Drug; D004906:Erythrocyte Count; D004912:Erythrocytes / Q000166:cytology; D007958:Leukocyte Count; D007962:Leukocytes / Q000166:cytology; D007964:Leukocytosis / Q000097:blood / Q000139:chemically induced* / Q000473:pathology; D008297:Male; D010659:Phenylhydrazines / Q000008:administration & dosage; D051381:Rats; D013950:Thymus Gland / Q000473:pathology; D013997:Time Factors
chemical_list: D010659:Phenylhydrazines; C030299:phenylhydrazine