Project Abstract

Abstract
The heart is a complex organ responsible for pumping blood throughout the body, composed of specialized tissues that allow it to function efficiently. Understanding the histology of the heart is crucial for gaining insights into its structure and function. Animal models, particularly adult Wistar rats, have been widely used in research to study various aspects of cardiac physiology and pathology. This study aimed to investigate the histological features of the heart in adult Wistar rats to provide a detailed characterization of its tissue composition. A total of 20 adult Wistar rats were included in the study, and their hearts were harvested for histological analysis. Tissue samples were processed, embedded in paraffin, sectioned, and stained with hematoxylin and eosin to visualize the cellular architecture of the heart. Additionally, special stains such as Masson's trichrome were used to evaluate the distribution of collagen fibers in the myocardium. The histological examination revealed the intricate structure of the heart, including the different layers of the myocardium (epicardium, myocardium, and endocardium) and the specialized cells such as cardiomyocytes, fibroblasts, and endothelial cells. The arrangement of cardiac muscle fibers was observed in a highly organized pattern, allowing for efficient contraction and relaxation during the cardiac cycle. The presence of intercalated discs between adjacent cardiomyocytes was also noted, highlighting the importance of cell-cell communication in cardiac function. Furthermore, the distribution of collagen fibers in the myocardium was assessed, showing a network of connective tissue that provides support and strength to the heart muscle. The balance between collagen synthesis and degradation is crucial for maintaining the structural integrity of the heart and preventing pathological remodeling. In conclusion, the histological analysis of the heart in adult Wistar rats provides valuable information about the structural components and organization of cardiac tissue. This study enhances our understanding of normal cardiac histology in a commonly used animal model, serving as a foundation for future research on cardiac diseases and potential therapeutic interventions. The findings contribute to the broader knowledge of cardiovascular physiology and pathology, ultimately leading to improved strategies for diagnosing and treating heart-related conditions.

Project Overview

3.1 SUBJECTS IN THIS STUDY

3.1.1 Model Animal – Adult Wistar rats. Sample size – Twenty (20) Wistar rats were procured from the Animal House of the Dpartment of Anatomy and Cell Biology of Delta State University, Abraka, Nigeria. The groupings of the rats were based on their weight. The weights range between 110 and 176 grams. The numbers of groups were four (4), with each group made up of five (5) rats. The Wistar rats were all fed with pelletized growers feed from Grand Cereals & Oil Mills Limited, a subsidiary of United Africa Company of Nigeria Plc, Jos and water was supplied ad libitum. The composition of the feed given to these animals is given in appendix 1. They were also exposed to a minimum of twelve hours of sunlight and adequate ventilation for the purpose of acclimatization.

3.1.2 TREATMENT Daily oral dose of 12.5mg (0.8ml), 25mg (0.7ml), and 50mg (0.75ml) of yohimbe pausinystalia was administered to the Wister rats in groups II, III and IV respectively for thirty days. The control group I was administered with a daily oral dose of 0.5 ml of distilled water for the same duration of thirty days.

3.1.3 GENERATION OF SAMPLES On the 30th day, six hours post oral administration of yohimbe pausinystalia the animals were sacrificed and their hearts obtained for histological analysis. 3.1.4 CHEMICALS/REAGENTS: The reagents and chemicals used and their sources are as follows: yohimbe pausinystalia), 10 % formal saline.

3.1.5 PREPARATION OF TISSUES FOR MICROSCOPY MATERIALS: 10 % formal saline, hearts, absolute alcohol, 95% alcohol, 70% alcohol, xylene, paraffin wax, oven, microtome, slides, borosilicate cover glass, microscope, digital microscope eyepiece.

METHODOLOGY: The process of preparation of testes for histological examination was separated into a number of stages. These stages included: Fixation, Tissue Processing, Sectioning, Staining and Photomicrography.

3.1.6 FIXATION After thirty days of oral administration of yohimbe pausinystalia, the rats in each group were sacrificed by cervical dislocation and the testes carefully removed whole and fixed in 10 % formal saline for 72 hours.

3.1.7 TISSUE PROCESSING The testes was cut along the coronal plane and processed using the automated tissue processor.

3.1.8 SECTIONING AND MOUNTING Sections were cut using the Rotary microtome with size 10 micron. The cut sections were floated on hot water bath, picked and mounted on clean slides for staining.

3.1.9 STAINING The routine staining technique employed in this preparation was the Haematoxylin and Eosin (H & E).