Oxygen uptake of mammary tissue of mice of the C57BL, A, and C3H strains has been studied in the presence [Formula: see text] and in the absence of p-phenylenediamine (Qo2). In general, these values are affected significantly by the age, sex, breeding history, and strain of the animals. The effect of these factors on enzyme activity has been observed with a number of enzyme systems and once more emphasizes their importance in evaluating data obtained in animal enzyme studies. A notable departure from the usual pattern for the Qo2 values was observed with mice of the C3H strain. There was a significant rise in the Qo2 values and a diminution in the cytochrome reserves [Formula: see text] for breeder females about the time spontaneous mammary tumors begin to appear. A similar elevation in Qo2, and diminution in reserves of the cytochrome system, appeared in mammary tumor tissue obtained from C3H females. The situation for virgin females is much the same with regard to the Qo2 and [Formula: see text] values of mammary tissue. The males of this strain manifest an abnormal elevation in Qo2 values but there is no diminution in [Formula: see text] levels.
MMP-7 derived peptides with MHC class-I binding motifs from canine mammary tumor tissue elicit strong antigen-specific T-cell responses in BALB/c mice