The Significance of Lipid Peroxidation and Glutathione in Reflux Esophagitis of Rats / 대한소화관운동학회지

The role of oxygen-derived free radicals has been studied in acute gastric and esophageal mucosal injury. OBJECTIVES: The aim of this study was to determine whether acid reflux causes oxidative stress in the esophageal mucosa and to investigate the correlation between mucosal glutathione (GSH) levels as an endogenous free radical scavenger and lipid peroxidation. METHODS: Eight-week-old male Sprague-Dawley rats with a bodyweight of 250-300 g were used for the experiments. Acid reflux was caused by pyloric ligation. The sham operation included a midline laparotomy and served as controls. After 24 hr all rats were killed and esophageal samples were taken for measurement of gross mucosal injury and mucosal GSH level. Lipid peroxidation which is a marker of oxidative stress was determined by measuring the formation of thiobarbituric acid-reactive substances (TBARS) spectrophotometrically. RESULTS: Severe mucosal damage was noted in reflux group. TBARS level was 6 times greater in reflux group compared to the control group (p < 0.05), while GSH level was 4 times less in reflux group compared to the control group (p < 0.05). Increase of TBARS level and decrease of GSH level showed a strong correlation to the gross findings of esophageal mucosal damage in reflux esophagitis. CONCLUSIONS: Oxygen-derived free radicals are of pathophysiologic importance in esophagitis caused by acid reflux.

MRI of the TSH(Thyroid Stimulating Hormone) -Secreting Pituitary Adenoma

PURPOSE: To demonstrate and evaluate the value of MRI findings of the TSH(Thyroid-Stimulating Hormone, TSH, Thyrotropin)-secreting pituitary adenoma. MATERIALS AND METHODS: The authors reviewed retrospectively the MR images of 4 patients with TSH-secreting pituiatary adenoma. Evaluation of the anatomical location, signal characteristics, enhancement patterns, size, shape and circunferential changes were made. RESULTS: No characteristic common MR findings in size, shape, signal intensity, and circumferential changes of TSH-secreting pituiatary adenoma waere observed among 4 cases(size; 5x7 mm to 10x11 mm, shape;ovoid to round, signal intensity;high in 1 case on T1 and T2WI, isosignal intensity in the other 3 cases, circumferential change; stalk deviation in 1 case, no stalk deviation in 3 cases). But, the tumors were centrally located at the anterior pituitary gland and showed relatively homogeneous signal intensity on MR images of all 4 patients. CONCLUSION: We conclude that centrally-located mass at the anterior pituitary gland with homogeneous signal intensity on MR image may be suggestive of the TSH-secreting pituitary adenoma, although the MR findings are not specific for the disease.