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).