Professor Smith I Jajastudied at the Department of Physiology, College of Medicine of the University of Lagos where he obtained the B.Sc., M.Sc. and Ph.D. degrees. He started his career in 1980 as a Graduate Assistant and rose to be appointed Professor of Physiology, University of Lagos in 2007. At different periods, he served as Visiting Professor in the Department of Physiology, School of Medicine, University of South Carolina, Columbia. USA, University of Ghana Medical School, University of Ghana, Accra and Lagos State University College of Medicine, Ikeja, Nigeria.
He served as External Examiner for the B.Sc. Physiology, 1st Professional MB.BS and B.D.S. degrees, M.Sc. and Ph.D. degrees in Universities in Nigeria, Ghana and the West Indies. He mentored several students in physiological sciences resulting in the successful graduation of fourteen (14) Ph.D. students. Prof. Jaja had also assessed several candidates for Professorial appointment in Universities in Nigeria, Ghana and the West Indies.
Professor Jaja’s major research interest is on “Antioxidants and Sickle Cell Disease”. Sickle cell disorders occur most frequently among people of African descent. Despite an increased understanding of the pathophysiology of sickle cell disease (SCD), there remains a paucity of available agents for its treatment. The theoretical basis of his studies was that the reduction in the generation of reactive oxygen species or the elevation of the level of antioxidants would ameliorate the deleterious effects of the disease in these sufferers.
His studies with Vitamin C and especially L-Arginine showed that antioxidants have promise in the management of sickle cell disease. Either agent reduced oxidative stress burden by elevating antioxidant enzymes, nitric oxide and trace metals levels but reduced lipid peroxidation in these sufferers. Although L-Arginine ameliorated insulin resistance and oxidative stress burden in these subjects, it did not affect impaired glucose and insulin responses to oral glucose tolerance test. His studies have also shown that in the steady state these subjects had lower GLUT 1 but elevated fasting blood glucose and fasting insulin levels than non-sickle cell subjects. Additionally, L-Arginine increased GLUT I and antioxidant enzymes but decreased fasting blood glucose, fasting insulin and lipid peroxidation in sickle cell disease subjects.
His other research interests are in Cardio-respiratory function in Health and Disease and Sleep deprivation and foetal programming. He was voted Best Teacher in Department of Physiology for 2016 and 2017 respectively by undergraduate students of the Faculty of Basic Medical Sciences of University of Lagos. He has published widely in national and international peer reviewed journals. He has travelled widely attending international and local conferences in several parts of the world. Prof Jaja belongs to several academic societies and is a Fellow of the Physiological Society of Nigeria which is affiliated to the African Association of Physiological Sciences and the International Union of Physiological Sciences.