Onyekwere Emmanuel Akwari
Professor of Surgery

Lab Disciplines:

Gastrointestinal Physiology (1) Motility: Electrical neural and gastrointestinal hormone regulation. Role of nutrients in the regulation of motility. (2) Pancreas: Islets of Langerhans: Direct effects of nutrients on hormone release by islets. (3) Whole animal perifusion and nutrients (rats).

Research Summary

1. Using computerized analysis of gastrointestinal electrical activity, the impact of operations, drugs and CNS lesions have been studied in large animals in the laboratory.

2. Scintigraphic techniques are employed to quantitate gastric emptying and radioimmunoassay to measure levels of GI peptide hormones. Issues such as the maintenance of glucose homeostasis and the effects of nutrient properties such as osmolarity and caloric density on function are studied in health and after surgical reconstruction of the upper digestive tract.

3. Techniques of in vitro perifusion of Islets of Langerhans have been established in the laboratory in collaboration with Dr. Emmanuel Opara. We study the direct effects of nutrients on hormone release by isolated microdissected mouse islets of Langerhans and the basic physiologic mechanisms regulating such release.

4. Fatty acid infusions both in vitro and in vivo cause a stimulatory effect on insulin secretion but this effect his accompanied by desensitization of the pancreatic islets to the insulinotropic effect of glucose. The mechanism of this desensitization and of its reversal by L-glutamine will be the subject of ongoing investigation in our laboratory. A common unifying hypothesis may be glutamine mediated increases in the antioxidant defenses of cells, so that L-glutamine may block the desensitizing effect of polyunsaturated fatty acids on insulin repose to glucose by increasing pancreatic anti-oxidated mechanisms.

Current Appointments & Affiliations

Contact Information

  • Box 3076, Durham, NC 27710
  • Box 3076 Med Ctr, Durham, NC 27710

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