Collagen quantification in the ventricular walls of the heart of the common marmoset (Callithrix jacchus).

The excellent adaptability of Callithrix jacchus to life in captivity presents advantages in comparison to other nonhuman primates that are used in experimental models for biomedical research, which explains the increasing scientific interest in investigating the anatomical characteristics of this species. Owing to the relative scarcity of publications on the descriptive morphology of the heart of C. jacchus, the aim of this study was to quantify the presence of collagen in the left and right ventricular myocardium using modified picrosirius red and acid fuchsine colorimetric assays. The myocardium of the right ventricle presented a higher percentage of collagen than that of the left ventricle. No sex-related differences were observed between the groups. Interestingly, the absolute values of collagen were different depending on the method used for quantification (modified picrosirius red vs. acid fuchsine). The level of collagen quantification observed in the ventricular myocardium of C. jacchus was similar to that seen in other nonhuman primates traditionally used in experimental models of cardiac diseases.