TY - JOUR
T1 - Apoptotic process in the monkey small intestinal epithelium
T2 - 2. Possible role of oxidative stress
AU - Madesh, M.
AU - Benard, O.
AU - Balasubramanian, K. A.
N1 - Funding Information:
Acknowledgements — The Wellcome Trust Research Laboratory is supported by The Wellcome Trust, London. Financial assistance from the Department of Science and Technology, Government of India is gratefully acknowledged. M. Madesh (SRF) and O. Benard (RA) are supported by the Council of Scientific and Industrial Research, India.
PY - 1999/2
Y1 - 1999/2
N2 - Recent findings suggest that intracellular oxidants are involved in the induction of apoptosis and this type of cell death can be inhibited by various antioxidants. In our accompanying paper we have shown apoptosis in the villus tip cells of the monkey small intestinal epithelium. The aim of the present study was to evaluate the possible relationship between oxidative stress, antioxidant levels and the apoptotic process in the monkey small intestinal epithelium. Monkey small intestinal epithelial cells were isolated into different fractions consisting of villus, middle and crypt cells. Mitochondrial function was assessed by the reduction of the tetrazolium dye, 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT), with and without succinate. The extent of lipid peroxidation was assessed by measuring the formation of conjugated diene, depletion of polyunsaturated fatty acids and α-tocopherol. Level of antioxidant enzymes like, superoxide dismutase (SOD), catalase, glutathione S-transferase (GST), glutathione peroxidase (GPx) and glutathione reductase were also quantitated in various cell fractions. MTT reduction was significantly decreased in villus cells as compared to the cells from other fractions and this was evident even in presence of the respiratory substrate, succinate. Increased formation of conjugated diene and depletion of polyunsaturated fatty acids were seen in villus and crypt cells as compared to middle fraction cells. The α- tocopherol level was decreased in both villus and crypt cells as compared to cells from middle region. Significant decrease of SOD activity was seen in the villus tip cells and a slight decrease was seen in the crypt fractions. Glutathione dependent enzymes like GST, GPx and GSH reductase showed higher activity in the villus fractions. A similar observation was also seen in the catalase activity. This study has shown that although oxidative stress is seen in both villus and crypt cells, decreased mitochondrial function was seen in villus tip cells which may be responsible for apoptotic process in the intestinal epithelium.
AB - Recent findings suggest that intracellular oxidants are involved in the induction of apoptosis and this type of cell death can be inhibited by various antioxidants. In our accompanying paper we have shown apoptosis in the villus tip cells of the monkey small intestinal epithelium. The aim of the present study was to evaluate the possible relationship between oxidative stress, antioxidant levels and the apoptotic process in the monkey small intestinal epithelium. Monkey small intestinal epithelial cells were isolated into different fractions consisting of villus, middle and crypt cells. Mitochondrial function was assessed by the reduction of the tetrazolium dye, 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT), with and without succinate. The extent of lipid peroxidation was assessed by measuring the formation of conjugated diene, depletion of polyunsaturated fatty acids and α-tocopherol. Level of antioxidant enzymes like, superoxide dismutase (SOD), catalase, glutathione S-transferase (GST), glutathione peroxidase (GPx) and glutathione reductase were also quantitated in various cell fractions. MTT reduction was significantly decreased in villus cells as compared to the cells from other fractions and this was evident even in presence of the respiratory substrate, succinate. Increased formation of conjugated diene and depletion of polyunsaturated fatty acids were seen in villus and crypt cells as compared to middle fraction cells. The α- tocopherol level was decreased in both villus and crypt cells as compared to cells from middle region. Significant decrease of SOD activity was seen in the villus tip cells and a slight decrease was seen in the crypt fractions. Glutathione dependent enzymes like GST, GPx and GSH reductase showed higher activity in the villus fractions. A similar observation was also seen in the catalase activity. This study has shown that although oxidative stress is seen in both villus and crypt cells, decreased mitochondrial function was seen in villus tip cells which may be responsible for apoptotic process in the intestinal epithelium.
KW - Apoptosis
KW - Free Radicals
KW - Intestinal epithelium
KW - Monkey
KW - Oxidative stress
UR - http://www.scopus.com/inward/record.url?scp=0032898279&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=0032898279&partnerID=8YFLogxK
U2 - 10.1016/S0891-5849(98)00218-4
DO - 10.1016/S0891-5849(98)00218-4
M3 - Article
C2 - 9895235
AN - SCOPUS:0032898279
SN - 0891-5849
VL - 26
SP - 431
EP - 438
JO - Free Radical Biology and Medicine
JF - Free Radical Biology and Medicine
IS - 3-4
ER -