Dose- and Time-Related Quantitative and Qualitative Alterations in the Granulocyte/Macrophage Progenitor Cell (GM-CFC) Compartment of Dogs after Total-Body Irradiation

Abstract

The effects of single-dose total-body X irradiation (TBI) on the granulocyte/macrophage progenitor cell (GM-CFC) population in bone marrow and blood of dogs were studied for dose levels of 0.78 and 1.57 Gy up to 164 days after irradiation. The blood GM-CFC concentration per milliliter was depressed in the first 7 days in a dose-dependent fashion to 5-16% of normal after 0.78 Gy and to between 0.7 and 5% after 1.57 Gy. The bone marrow GM-CFC concentration per 10(5) mononuclear cells, on the other hand, was initially reduced to about 45% of the average pre-irradiation value after 0.78 Gy and to 23% after 1.57 Gy. The regeneration within the first 30 to 40 days after TBI of the blood granulocyte values and the repopulation of the bone marrow GM-CFC compartment was associated with both a dose-dependent increase in the S-phase fraction of the bone marrow GM-CFC and a dose-dependent increase in colony-stimulating activity (CSA) in the serum. The slow repopulation of circulating blood GM-CFC to about only 50% of normal even between days 157 and 164 after TBI could be related to a correspondingly delayed reconstitution of the mobilizable GM-CFC subpopulation in the bone marrow.

Chapter 6: Cell and cell system responses: Response of hemopoiesis in dogs to continuous low dose rate total body irradiation

“…Thereafter the pool size decreased again to extremely low GM-CFC numbers. Several other studies in dogs have shown [17][18][19][20] that any damage by radiation to certain fractions of bone marrow will cause a depression in the concentration of GM-CFC in the blood for several weeks and months after the acute exposure. The results obtained from determinations of GM-CFC in the blood of the continuously irradiated dogs are presented in Figure 5.…”

Contralateral response of macrophages and astrocytes to injury in the cerebral hemisphere of 6‐day‐old rat following prenatal gamma irradiation

“…The whole-body irradiation at different stages of prenatal development affected also populations of haemopoietic cells located in different organs and having different recovery abilities (Koshimoto et al, 1994;Morris et al, 1991;Weinberg, 1983). This should result in different long-term functional impairments of the system both in developing and adult individuals (Gidali et al, 1985;Grande and Bueren, 1995;Nothdurft et al, 1984;Weinberg, 1983;Weinberg et al, 1983).…”

“…In the present study, exposure to gamma radiation at different stages of prenatal development affected different populations of haemopoietic cells located in different organs (Koshimoto et al, 1994;Morris et al, 1991). It interrupted ontogenesis of the mononuclear phagocyte system which is an exogenous source of microglia/macrophages acting in the nervous tissue following injury (Gidali et al, 1985;Grande and Bueren, 1995;Nothdurft et al, 1984;Weinberg, 1983;Weinberg et al, 1983). The recruitment of macrophages to the lesion site and their proliferation might, therefore, be modified in a way dependent on the stage of prenatal development at which the irradiation was performed.…”

In VitroStudies of the Sensitivity of Canine Bone-marrow Erythroid Burst-forming Units (BFU-E) and Fibroblast Colony-forming Units (CFU-F) to X-irradiation

“…PIDS was collected and pooled from three dogs at day 9 after total body irradition with 3 . 9 Gy (Nothdurft et al 1984) . For each experimental point three Petri dishes (Greiner, 35 mm) were prepared and incubated for 9 days at 37°C in a humidified atmosphere containing 5 per cent CO 2 .…”