Biomaterial Database

Enhancement of natural killer-cell activity in young and old mice treated with cyclophosphamide on a circadian basis. 1987

L E Sandberg, and G Fernandes

Several recent studies have revealed a significant circadian variation in immunological functions including natural killer (NK)-cell activity against tumor target cells both in rodents and in man. We have previously reported circadian changes in antibody-forming cells as well as NK-cell activity in mice and rats. The present study was undertaken to determine the effect of high and low doses of cyclophosphamide on circadian NK-cell activity in young (8-week-old) and old (8-month-old) female C57BL/6 (B/6) mice. The results revealed that, in general, young animals had higher NK activity than old animals. In both young and old mice, the high dose of cyclophosphamide depressed NK activity. In contrast, the low dose of cyclophosphamide showed significantly increased NK activity, which was proportionately greater in old mice than in young mice. Cyclophosphamide-enhanced NK activity was found to be higher during the resting period than during periods of activity. Apparently, high NK activity can be induced with a circadian-based immunotherapy regime using low-dose cyclophosphamide in both young and old animals. It is presently not clear if increased NK activity caused by cyclophosphamide is due to a decrease in activity of immunoregulatory cells, such as T cells, B cells, or macrophages. More studies are required to determine the basis of increased NK activity caused by treatment with low dosages of cyclophosphamide in mice.

UI	MeSH Term	Description	Entries
D007694	Killer Cells, Natural	Bone marrow-derived lymphocytes that possess cytotoxic properties, classically directed against transformed and virus-infected cells. Unlike T CELLS; and B CELLS; NK CELLS are not antigen specific. The cytotoxicity of natural killer cells is determined by the collective signaling of an array of inhibitory and stimulatory CELL SURFACE RECEPTORS. A subset of T-LYMPHOCYTES referred to as NATURAL KILLER T CELLS shares some of the properties of this cell type.	NK Cells,Natural Killer Cells,Cell, NK,Cell, Natural Killer,Cells, NK,Cells, Natural Killer,Killer Cell, Natural,NK Cell,Natural Killer Cell
D002940	Circadian Rhythm	The regular recurrence, in cycles of about 24 hours, of biological processes or activities, such as sensitivity to drugs or environmental and physiological stimuli.	Diurnal Rhythm,Nyctohemeral Rhythm,Twenty-Four Hour Rhythm,Nycthemeral Rhythm,Circadian Rhythms,Diurnal Rhythms,Nycthemeral Rhythms,Nyctohemeral Rhythms,Rhythm, Circadian,Rhythm, Diurnal,Rhythm, Nycthemeral,Rhythm, Nyctohemeral,Rhythm, Twenty-Four Hour,Rhythms, Circadian,Rhythms, Diurnal,Rhythms, Nycthemeral,Rhythms, Nyctohemeral,Rhythms, Twenty-Four Hour,Twenty Four Hour Rhythm,Twenty-Four Hour Rhythms
D003520	Cyclophosphamide	Precursor of an alkylating nitrogen mustard antineoplastic and immunosuppressive agent that must be activated in the LIVER to form the active aldophosphamide. It has been used in the treatment of LYMPHOMA and LEUKEMIA. Its side effect, ALOPECIA, has been used for defleecing sheep. Cyclophosphamide may also cause sterility, birth defects, mutations, and cancer.	(+,-)-2-(bis(2-Chloroethyl)amino)tetrahydro-2H-1,3,2-oxazaphosphorine 2-Oxide Monohydrate,B-518,Cyclophosphamide Anhydrous,Cyclophosphamide Monohydrate,Cyclophosphamide, (R)-Isomer,Cyclophosphamide, (S)-Isomer,Cyclophosphane,Cytophosphan,Cytophosphane,Cytoxan,Endoxan,NSC-26271,Neosar,Procytox,Sendoxan,B 518,B518,NSC 26271,NSC26271
D000367	Age Factors	Age as a constituent element or influence contributing to the production of a result. It may be applicable to the cause or the effect of a circumstance. It is used with human or animal concepts but should be differentiated from AGING, a physiological process, and TIME FACTORS which refers only to the passage of time.	Age Reporting,Age Factor,Factor, Age,Factors, Age
D000818	Animals	Unicellular or multicellular, heterotrophic organisms, that have sensation and the power of voluntary movement. Under the older five kingdom paradigm, Animalia was one of the kingdoms. Under the modern three domain model, Animalia represents one of the many groups in the domain EUKARYOTA.	Animal,Metazoa,Animalia
D013154	Spleen	An encapsulated lymphatic organ through which venous blood filters.
D013268	Stimulation, Chemical	The increase in a measurable parameter of a PHYSIOLOGICAL PROCESS, including cellular, microbial, and plant; immunological, cardiovascular, respiratory, reproductive, urinary, digestive, neural, musculoskeletal, ocular, and skin physiological processes; or METABOLIC PROCESS, including enzymatic and other pharmacological processes, by a drug or other chemical.	Chemical Stimulation,Chemical Stimulations,Stimulations, Chemical
D051379	Mice	The common name for the genus Mus.	Mice, House,Mus,Mus musculus,Mice, Laboratory,Mouse,Mouse, House,Mouse, Laboratory,Mouse, Swiss,Mus domesticus,Mus musculus domesticus,Swiss Mice,House Mice,House Mouse,Laboratory Mice,Laboratory Mouse,Mice, Swiss,Swiss Mouse,domesticus, Mus musculus