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Biomedical subjects

M C Aggio

Publications and source records attributed to M C Aggio.

At least 37 records · Page 2Linked to original sources
PubMed1977

Some aspects of iron metabolism during erythropoietic depression in the mouse.

Spleen and bone marrow patterns of response differ in mice subjected to erythropoietic depressors. Radioiron injected a few hours after a high dose of cyclophosphamide or x-irradiation is retained in the bone marrow. The magnitude of medullary retention is closely related to the number of cells able to synthesize hemoglobin at the moment of iron administration, and to the rate of cell death provoked by the cytotoxic agent. Depressors such as Actinomycin and transfusion, that block the differentiation of stem cells while allowing normal maturation of the erythroid cohort, do not induce marrow entrapment of iron. By contrast, retention is never observed in the spleen, where the 59-Fe turnover is not influenced by the mechanism and magnitude of aplasia. A functional lack of homogeneity of splenic and bone marrow erythropoiesis, hemoglobin metabolism and/or handling of iron stores is proposed. These results would be in agreement with other data from the literature reporting physiological differences among the various sectors of the reticuloendothelial system.

Animals↗
PubMed1975

Effect of beta adrenergic blockade on surviving to acute hypoxia in mice.

A significant protection against the lethal effects of hypobaric and isobaric hypoxia is observed in mice treated with propranolol. Previous acclimatization to chronic hypoxia does not introduce variations on this protective effect of the beta adrenergic blocking drugs. Similar effects were found using histotoxic anoxia provoked by sodium azide administration. A significative reduction of body temperature is observed under the effects of the blockaders. These findings suggest a reduced need of oxygen in the treated animals. Neutralization of the effects of epinephrine released as a consequence of the hypoxic stress is proposed as the protection mechanism.

Animals↗
PubMed1975

The role of autotransplanted spleen in the erythropoietic recovery of the mouse.

Erythropoietic recovery was studied in mice subjected to subcutaneous splenic autotransplantation and compared with that observed in normal and splenectomized animals. Radioiron uptake into spleen and erythrocytes and splenic weight were measured at different times after lethal irradiation and injection of 5 x 10(5) bone marrow cells. Dose-response curves were also performed with increasing amounts of cells injected. Hematocrit recovery as a function of time after a single large dose of phenylhydrazine was also studied. Results indicate that autotransplants act qualitatively as normal spleens, but their erythropoietic capacity is diminished and the animals show an intermediate response between normal and splenectomized mice. Histological observation showed no obvious differences in morphology and spatial distribution between colonies developing in normal and transplanted spleens. It is concluded that transplants lead to normal lodgment, proliferation and erythroid differentiation of circulating stem cells. However, changes in transplant size, anatomical position and other factors such as fibrosis and blood flow may decrease their trapping area and their capacity of expansion even under conditions of high erythropoietic stimulation.

Anemia, Hemolytic↗