title: Age-related changes in the bone marrow and spleen of SAS/4 mice.
abstract: The total number of nucleated cells in the bone marrow of SAS/4 mice increase some twofold between 1 and 24 months of age but when related to body weight remains essentially constant over a wide range of ages. The concentration of CFU-S in femoral marrow is also constant with age and since other bones containing marrow appear, at least in young mice, to have the same CFU-S concentration as the femur it is concluded that the CFU-S compartment size of the whole bone marrow is independent of age when expressed on a body weight basis, In contrast, both the absolute number and the concentration of exogenous CFU-S in the spleen decline markedly in old mice. Smilary there is a decline in the number of endogenous colony-forming cells and the spleens of 24-month-old mice seem virtually devoid of such colonies. Not only were older mice less capable of supporting the growth of endogenous colonies, but their spleens also appear to provide a poorer environment for exogenous colony growth when compared with growth in younger recipient spleens.
mesh_terms: D000375:Aging; D000818:Animals; D001835:Body Weight; D001853:Bone Marrow / Q000502:physiology* / Q000528:radiation effects; D001854:Bone Marrow Cells; D016026:Bone Marrow Transplantation; D002455:Cell Division; D002467:Cell Nucleus / Q000502:physiology; D002999:Clone Cells / Q000502:physiology; D003037:Cobalt Radioisotopes; D005260:Female; D005269:Femur / Q000166:cytology; D008297:Male; D051379:Mice; D011829:Radiation Dosage; D011830:Radiation Effects; D013154:Spleen / Q000166:cytology / Q000502:physiology* / Q000528:radiation effects; D014184:Transplantation, Homologous
chemical_list: D003037:Cobalt Radioisotopes