title: Dissecting the hematopoietic microenvironment. III. Evidence for a positive short range stimulus for cellular proliferation.
abstract: Experiments were carried out with the intent of defining the nature of the microenvironmental defect which severely limits erythropoiesis in the spleen of the S1/S1d mouse. Chimeric spleens, half S1/S1d and half congenic +/+, supported erythropoiesis in the +/+ region but not in the S1/S1d region, regardless of which genotype was the irradiated, marrow-injected host animal. Implants of normal marrow stroma within the spleens of irradiated S1/S1d mice also supported normal proportions of erythrocytic and granulocytic hematopoiesis. Implants of normal spleen stroma, particularly the capsular portion, into unirradiated s1/s1d mice stimulated erythropoiesis originating from S1/S1d stem cells within and in the immediate vicinity of the implant. The evidence suggests a short range, stromal erythropoietic stimulatory factor which is lacking in the S1/S1d.
mesh_terms: D000748:Anemia, Macrocytic / Q000235:genetics / Q000503:physiopathology*; D000818:Animals; D016026:Bone Marrow Transplantation; D002455:Cell Division; D004920:Erythropoiesis; D005260:Female; D005838:Genotype; D008297:Male; D051379:Mice; D008815:Mice, Inbred Strains; D011828:Radiation Chimera; D013154:Spleen / Q000502:physiology* / Q000637:transplantation; D014184:Transplantation, Homologous