Dr. Dikshit, M.

Dr. Madhu Dikshit, Head, Cardiovascular Pharmacology Unit, Pharmacology Division, Central Drug Research Institute, Lucknow. She is the recipient of several prestigious national and international awards. She is on the editorial boards of various national journals and is an elected Fellow of the Indian Academy of Sciences and Fellow of The National Academy of Sciences, India.

Lab Module
Dr. Dikshit in association with Dr. Padma Narayanan will discuss the role of nitric oxide (NO) in physiological (regulation of PMNs, platelet, and vascular responses) and various pathological (hypertension, neurodegeneration, and disruption of the blood-brain barrier) conditions. These studies highlight role and regulation of neutrophils (polymorphonuclear leukocytes (PMNs) and endothelial cell derived free radicals (NO and ROS) and demonstrated their important physiological regulatory role. PMNs, the least explored cells, synthesize NO at an equivalent rate to endothelial cells, thereby imparting importance to the studies on PMNs in relation to cardiovascular system. Her studies have demonstrated significant alterations in the release of NO specifically from PMNs in experimental models of thrombosis, hypoxia-reoxygenation, sepsis, and in CNS disorder patients. Immunocytochemical, molecular and biochemical studies on PMNs in her lab have unravelled unique features of NOS - localization, expression of splice variants and regulation of enzymatic NO synthesis. Her recent studies on PMNs have demonstrated role of ascorbic acid in regulation of the enzymatic synthesis of NO by stabilizing tetrahydrobiopterin. Thus the dogma that radicals are always toxic no longer holds true and her work has demonstrated that both ROS and RNS have a regulatory role in platelet and PMNs activation, vasoreactivity modulation.

Relevant Literature
Dixit C and Dikshit M. A flow cytometric method for evaluation of acid secretion from isolated rat gastric mucosal cells. J Pharmacol Toxicol Methods, 45: 47-53, 2001.

Sethi S, Sharma P and Dikshit M. Nitric oxide and oxygen derived free radical generation from control and lipopolysaccharide treated rat polymorphonuclear leukocyte. Nitric Oxide Biol. Chem., 5: 482-493, 2001.

Sharma P, Raghavan SAV and Dikshit M. Role of ascorbate in the regulation of nitric oxide generation by polymorphonuclear leukocytes. Biochem Biophys Res Commun 309: 12-17, 2003.

Sharma P, Raghavan SAV, and Dikshit M. Ascorbate mediated enhancement of reactive oxygen species generation from polymorphonuclear leukocytes: modulatory effect of nitric oxide. J Leuko Biol 75: 1070-1078, 2004

Saini R, Patel S, Saluja R, Sahasrabuddhe AA, Singh MP, Habib S, Bajpai VK, andDikshit M. Nitric oxide synthase localization in the rat neutrophils: immunocytochemical, molecular and biochemical studies. J Leukocyte Biol 79:519-28, 2006.

Kavya R, Rohit Saluja R, Singh S, and Dikshit M. Nitric oxide synthase regulation and diversity: Implications in Parkinson's disease. Nitric Oxide. 15: 280-294, 2006.