Abstract

In this study, the aim was to investigate effects of routine protocols commonly used in pathology (formalin fixation, paraffin embedding, slicing and staining) on morphometrical parameters of hearts in rats. Six males and 6 females rats were used. All of the subjects were euthanized and then hearts were fixed in formalin solution. Hearts were cut at the level of musculus papillaris and cut surfaces area were photographed (Formalin group). Thereafter, cut surfaces of the hearts embedded in paraffin were also photographed (Paraffin group). Staining was done using H&E staining on 5 µm slices and their photographs were taken (Slide Group). Analyses of thickness, diameter and area on the photographs of heart were done by using image analysis software. Left ventricular mass (LVM), left ventricular mass index (LVMI) and cut surface area (CSA) were calculated. Significant differences were found in LVM and LVMI values between Paraffin and Formalin groups (p<0.05). Comparisons between males and females in accordance to their respective groups showed that there were no differences in Slide group (p>0.05) but there were significant differences in CSA values of Paraffin and Formalin group (p<0.05). In conclusion, in case reports, in which left ventricular hypertrophy is investigated by the help of LVM and LVMI, Formalin and Slide group method and results might be more useful. On the other hand, all the three methods might be used in experimental studies included in healthy control groups. Additionally, it was discussed that the gender has no effect on evaluation among groups in terms of LVM and LVMI.

Key words: Morphometry, heart, rat, routine pathology, left ventricular mass (LVM)