Production of presumptive humoral haematopoietic regulators in canine cyclic haematopoiesis |
| |
| Authors: | C. D. R. Dunn ,J. B. Jones &Dagger ,R. D. Lange &dagger ,E. G. Wright§ ,M. A. S. Moore¶ |
| |
| Affiliation: | *The Department of Medical Biology, Memorial Research Center;†The Department of Internal Medicine, The University of Tennessee College of Medicine, Knoxville Units;‡The University of Tennessee College of Veterinary Medicine, Knoxville, Tennessee, U.S.A.;§Department of Experimental Haematology, Paterson Laboratories, Christie Hospital &Holt Radium Institute, Manchester, England;¶The Sloan-Kettering Institute for Cancer Research, Rye, New York. USA. |
| |
| Abstract: | Abstract. Conditioned media (CM) were prepared according to previously published techniques from the bone marrow of dogs with cyclic haematopoiesis (CH). CM prepared from day 9 marrows inhibited mouse bone marrow CFU-s proliferation rate while CM from day 10 marrows were stimulatory and also contained an erythroid stimulating factor which appeared to be erythropoietin. In addition a highly significant trend from CM containing CFU-s inhibitory materials to media with CFU-s stimulatory activity was observed through cycles day 1 to 8. These studies further support the concept that CH is due to a defect in factors controlling stem cell proliferation and suggest that a major event occurs in CH dog marrow on days 9 and/or 10 of the cycle. Bone marrow transplantation studies (Dale & Graw, 1974; Weiden et al., 1974; Jones et al., 1975b) have indicated that canine cyclic haematopoiesis (CH) is probably due to a disorder in the multipotential stem cells. Morphological evidence (Scott et al., 1973) and the almost synchronous cycling of CFU-e, CFU-c and diffusion chamber progenitor cells (DCPC) (DUM et al., 1977, 1978a, b) lend support to such a theory. However, efforts to identify the mechanisms controlliig multipotential stem cell proliferation in dogs have been handicapped by the lack of suitable techniques to study these cells in the canine. Recently, Wright and co-workers (Wright & Lord, 1978, 1979; Wright et al., 1979; Lord et al., 1979), on the basis of previous observations (Frindel et al., 1976; Frindel & Guigon, 1977), described the preparation of species non-specific, bone marrow conditioned media (CM) which are capable of influencing the proliferation rate of murine colony forming units-spleen (CFU-s). The studies now reported were designed to determine if CM prepared from canine CH marrow would influence the proliferation rate of murine bone marrow CFU-s. The results indicate that a major event, possibly related to the in vivo control of stem cell proliferation in dogs with CH, occurs on days 9–10 of the cycle; day 1 being the first day when the peripheral blood neutrophil count falls below-1600 mm3. |
| |
| Keywords: | |
|
|
