Body growth and polycythaemia in hypoxic albino rats of first and second generation.

1. In our study we followed the growth rate and the haematologic changes occurring in albino rats of Wistar strain when living in a hypoxic environment. Two generations of hypoxic rats were observed for changes in their erythrocytes (RBC), haematocrit (Hct) and haemoglobin (Hb): the first generation (H1) and the second generation (H2). A few hours after birth, the H1 rats were placed and raised in a normobaric hypoxic environment (10% O2 in N2). The H2 rats were born and raised in the environment previously described. The control group had a normoxic environment. The H1 and H2 rats had inferior growth rates in respect to their controls, but H2 were found to have a larger growth rate than the H1 group. The RBC, Hct and Hb had values significantly greater for both H1 and H2 when compared with their controls. However, we did find that the values of H2 were significantly lower than H1. We believe that these results are in relation to the degree of development of the adaptive processes to the hypoxic environment of the H2 rats.