Dissertations in Physiology http://adhlui.com.ui.edu.ng/jspui/handle/123456789/347 2026-02-28T07:25:24Z 2026-02-28T07:25:24Z MORAKINYO, O. L. http://adhlui.com.ui.edu.ng/jspui/handle/123456789/860 2019-04-30T10:11:03Z 2016-03-01T00:00:00Z

Title: THE EFFECTS OF CHRONIC EXPOSURE TO CHROMIUM SALTS ON GASTRIC ULCERATION IN MALE WISTAR RATS Authors: MORAKINYO, O. L. Abstract: The gastrointestinal tract is constantly exposed to various protective and aggressive factors from food. Recent studies have shown that factors, including heavy metal exposure and diet may alter gastrointestinal mucosal integrity. Chromium (Cr), a naturally occurring polyvalent element found in rocks, soil and gases is known to be present in whole grains, wheat, cereal, lettuce, onions, potatoes, green beans, raw tomatoes and many other food items. The role of Cr in gastrointestinal mucosa protection or erosion is not well studied. In this study, the effects of exposure to tri-and hexavalent Cr on gastric ulcer were investigated in rats. Sixty male Wistar rats (100-120g) were randomly assigned to six groups of 10 animals each. Four groups were treated with Cr; Chromium III-10ppm (CrIII-10), Chromium III-100 ppm (CrIII-100), Chromium VI-10ppm (CrVI-10) and Chromium VI-100pm (CrVI-100) while the remaining two groups were non-ulcerated control (nCont) and ulcerated control (uCont). Twelve weeks after Cr administration, experimental gastric ulcers were induced via pylorus ligation (PL) technique (a=5 per group). In the remaining five animals, ulcer was induced by oral administration of indomethacin (40mg/kg). In both ulcer models, animals were sacrificed four hours after ulcer induction. Blood and stomach biopsies were collected and analysed. Ulcer was assessed based on macroscopic appearance of the stomach using standard ulcer score scale. Lipid peroxidation, catalase and Superoxide Dismutase (SOD) activities of the stomach homogenates were assessed by spectrophotometry. Histology of the stomach tissues were assessed to determine the degree of tissue damage using microscopy. Blood were subjected to descriptive statistics and analysed using ANOVA at α>0.05. The blood Cr level was significantly increased in the Cr treated groups (CrIII-10: 0.12±0.01 ppm; CrIII-100: 0.12±0.01 ppm; CrVI-10: 0.13±0.01 ppm and CrVI-100:0.12±0.03 ppm) compared with nCont (0.08±0.01 ppm). Ulcer scores were nCont (0.0±0.0; 0.0±0.0), uCont (4.0±0.5; 12.6±0.5), CrIII-10 (1.6±0.2 ; 10.3±0.5), CrIII-100 (2.8±0.1; 10.8±0.2), CrVI-10 (1.8±0.3, 11.4±0.5) and CrVI-100 (2.8±0.3; 12.1±0.5) for PL and indomethacin, respectively. Various degrees of gastric protection were observed in the two ulcer models on exposure to CrIII-10(59.4%, 18.7%), CrIII-100 (31.3%; 14.5%), CrVI-10 (56.3%; 9.7%) and CrVI-100 (31.3%; 4.0%). There were significant decreases in gastric acidity in Cr- treated groups (CrIII-10:12.0±1.0; CrIII-100: 26.9±2.3 mEq/L/100g: CrVI-10: 16.0±1.5: CrVI-100: 26.8 ±1.5 mEq/L/100g) compared with uCont (34.0±1.0 mEq/L/100g) for PL model. Lipid peroxidation levels in both PL and indomethacin ulcer models were significantly in uCont (11.9±0.1; 6.3±0.1 nmol/mg) than Cr- treated groups (CrIII-10: 8.2±0.1; 4.9±0.0; 4.9±0.0; CrIII-100: 9.0±0.3: 5.3±0.1 nmol/mg; CrVI-10: 8.9±0.3: 5.6±0.0: CrVI-100: 9.7±0.2: 6.0±0.0 nmol/mg). The activities of SOD and catalase were elevated in Cr-treated groups of both ulcer models relative to uCont. Ulcer score results were further corroborated by histological evaluation which revealed mild erosion of surface epithelium in the Cr-treated groups against visible lesions in uCont. Both tri and hexavalent Chromium offers protection against gastric ulcer induced by pylorus ligation and indomathacin via reduction of gastric oxidative stress. Description: A Dissertation submitted in partial fulfillment of the requirements for the award of Master of Philosophy (M.Phil) Degree in Physiology in the Department of Physiology, College of Medicine, University of Ibadan, Nigeria.

2016-03-01T00:00:00Z UGWU, A. C. http://adhlui.com.ui.edu.ng/jspui/handle/123456789/393 2019-04-30T10:12:56Z 1982-12-01T00:00:00Z

Title: EFFECTS OF TEMPERATURE AND EXERCISE ON THE PRODUCTION AND COMPOSITION OF SWEAT IN NIGERIANS Authors: UGWU, A. C. Abstract: An investigation into the effects of temperature and exercise on the production and composition of sweat in Nigerians was carried out on healthy male adults. Sweat was induced in a sweat chamber under normal, exercise and raised temperature conditions. The rate of sweat production was measured and sweat samples were analysed for the electrolytes and proteins. The exercise and raised temperature conditions were found to increase the sweat rate significantly over their values under the normal conditions. In addition, these conditions produced significantly higher values of the sweat electrolytes and proteins. However, it was noted that the raised temperature conditions did not significantly increase the values of the sodium from the forehead and the chloride from the forearm. Generally, the effects of exercise conditions on the values of the sweat rate, sweat electrolytes and proteins were significantly higher than those of the raised temperature conditions. The electrolyte ratios, the hydrogen ion concentration and the total cations and anions of the sweat samples varied with the experimental conditions. It was suggested that the requirements of the body for evaporative heat dissipation might account for the significant increase in the sweat rate. The significant increase in the sweat electrolytes and proteins was also linked to the increase of these substances from the body with the increase in sweat rate. It was suggested that the differences in the original distribution of functioning active sweat glands might account for the slight difference in the forehead and forearms sweat values. It is probable that the variation in the values of the sweat rate , sweat electrolytes and sweat proteins with the different experimental conditions were mainly due to the different level at which each experimental condition is able to induce sweating. Since the values of the sweat rate and sweat electrolytes obtained for Nigerians are similar to those of the Caucasians, it was suggested that the sweating characteristics of the two races are qualitatively similar but natural climatic environments under which the two races sweat impose quantitative differences. Description: A Dissertation in the Department of Physiology submitted to the Faculty of Basic Medical Sciences and Pharmacy of the College of Medicine, University of Ibadan in partial fulfillment of the requirements for the award of the Degree of Master of Philosophy of the University of Ibadan, Nigeria.

1982-12-01T00:00:00Z