Morphometric and Anatomical Evaluation of the Heart of Wistar Rats

The use of animals in scientific research is not recent. The rat has been used in experiments since before Christ and, in the XIX century, with the intensification of the research reports, the use of this species increased considerably. Although this fact happens, the literature regarding the heart of these animals is not very detailed and descriptive. The objective of this research is to study the macroscopic morphometric of several parameters that have not been described yet regarding the hearth of Wistar rats in different phases of their lives. Thirty-six adult male and female rats (Rattus norvegicus) weighing 150-770 g were randomly divided into 6 experimental groups: 6 animals of the group I male-weighting 150-249g (I-M); 6 animals of the group I female-weighting 150-249g (I-F); 6 animals of the group II male-weighting 250-350g (II-M); 6 animals of the group II-female-weighting (II-F); 6 animals of the group III-male weighting more than 35 g (III-M); 6 animals of the group III-female weighting more than 351g (III-F). The heart was then carefully dissected and removed from the chest. After this process, the heart had their weight measured on a precision scale HELMAC HM100, and for each front section of the heart were taken related measures through a semi-automatic image analysis of Kontron Build Analyse (Minimop). The percentage ratio between the relative heart weight to body weight was between 0.5 and 0.7% in the animals with body weight up to 650g, moreover, the wall thickness of the non-septal left ventricle was always lower for the females in all groups, while the interatrial septum have similar action in males and females and the thickness of the interventricular septum demonstrated to be similar to the wall thickness of the non-septal left ventricle.