Clinical parameters of the normal baboons (Papio species) and chimpanzees (Pan troglodytes).

Improved equipment and advanced progressive techniques by scientists using baboons and chimpanzees in biomedical research have resulted in improved clinical laboratory data. The use of state-of-the-art clinical laboratory instruments, methodologies with improved accuracy, and an increased variety of individual tests routinely requested and performed has necessitated the comparison of current data with prior data produced in our laboratory and with those values reported in the literature. In addition to an expanded hematologic profile, including red blood cell distribution width and mean platelet volume, and a more comprehensive chemical profile of 28 individual tests, additional data collected included values for coagulation profiles, arterial blood gases, serum protein electrophoresis, and urine osmolalities. Samples for evaluation were obtained from clinically normal sedated adult baboons (Papio species) and chimpanzees (Pan troglodytes) and processed conventionally according to Good Laboratory Practice Act standards. Arithmetic means were calculated, values of 3 standard deviations or greater were eliminated, and means were recalculated to include 2 standard deviations. All data correlated well with prior in-house values, and no remarkable differences from established data were detected, thus indicating the reliability of past and present data. Data compared favorably with normal clinical values established for humans.

Effects of chronic blood loss in a marsupial (Monodelphis domestica).

Monodelphis domestica, the gray short-tailed opossum, is used increasingly as an animal model in studies that require repeated blood sampling. Consequently, it is important to establish safe bleeding regimens. We investigated the effects of repeated blood loss on various hematologic values and on different organs in this species. Approximately 2 ml of blood were taken weekly from 20 animals for 13 weeks. The animals were then necropsied; members of an age- and sex-matched control group were bled (2 ml) once and necropsied immediately to obtain baseline data. Ultimately, each animal in the experimental group lost approximately three times its total blood volume. After the first bleeding in the chronically bled group, the red blood cell counts, hemoglobin, and hematocrit values decreased significantly but remained constant thereafter. In another experimental group bled only once, the hematologic values rose to higher than baseline levels after a rest of 2 weeks. Thereafter the values slowly returned to baseline levels. A notable increase in Howell-Jolly bodies occurred in the chronically bled group. Histologically, there was marked erythroid hyperplasia in the bone marrow and extramedullary hematopoiesis in the spleen, but none in the liver. Because there were no obvious detrimental physiologic effects, we conclude that M. domestica is markedly tolerant of chronic blood loss.