Research area:

Cell Biology and Nutritional Physiology

Research description:

The nature of my present research program involves aspects of gastrointestinal physiology that seeks to identify methods of beneficially altering digestive function, specifically pancreatic function, in vertebrates. The philosophy of the program is that the best way of altering gastrointestinal function is to thoroughly understand regulatory mechanisms. The approach is to examine regulatory mechanisms that could enhance pancreatic function via the autonomic nervous system. The overall achievement of this concept of regulating gut function will be to enhance nutrient utilization in domestic animal species.

My research goals center around understanding how much of gastrointestinal function is under neural regulation and to determine whether this type of regulation can be manipulated to enhance digestive function for nutrient assimilation and effects on metabolism. Specifically, this will involve understanding how neural elements (receptors) regulate pancreatic functions associated with digestion. An embryonic chick organ culture system has been developed as a model to help determine how the parasympathetic nervous system (cholinergic mechanisms) controls pancreatic functions.

Funding sources:

UAH Mini Grants, NSF, USDA (Collaboration AAMU)

Selected Publications:

Collier, L. J. U. Johnson, and A. D. Johnson, Sr. 2001. Pharmacological studies examining the effects of cholinergic agents on the embryonic chick pancreas. J. Alabama Academy of Science 72:2, 99.

Johnson, J. U. and A. D. Johnson, Sr. 2001. The effect of gender and reproductive status on serum amylase and acid phosphatase activity in rabbits. J. Alabama Academy of Science 69:2, 85.

Scott, K., L. Perry, O. Emonina, L. McCants, L. Collier, D. Cowley, D. Carswell,
A.D. Johnson,J. U. Johnson, A.Hulede.1998. Studies evaluating amylase and acid phosphatase in rabbit secretions.J. Alabama Academy of Science 69:2, 60.

Johnson, J.U., and A.D. Johnson. 1996. Superovulating NZW rabbits: Maximizing embryo yields while minimizing hyperemic uterine conditions. J. Alabama Academy of Science 67:2, 61.

Meacham, C., N. German, K. Allison, and A. D. Johnson. 1995. Characterizing viability in the embryonic chick pancreas using immunoflorescence techniques. J. Alabama Academy of Science 66:1-2, 10.

German, N., C. A. Meacham, and A. D. Johnson. 1995. Effects of cholinergic agents on secretion using a rat pancreatic cell dispersion system. J. Alabama Academy of Science 66:1-2, 13.

Johnson, A.D., W.J. Croom, Jr., W.M. Hagler, Jr., and J.F. Ort. 1995. Effects of cholinergic antagonists on carbachol stimulated pancreatic amylase release from a chick organ culture system.J. Chinese Society of Animal Science 24:4,471-485.

Meacham, C.A., N.S. German, and A.D. Johnson. 1994. Muscarinic receptors mediate amylase release from exocrine tissue in the embryonic chick pancreas. Molecular Biology of the Cell.5:116a.

Johnson, A.D., W.J. Croom, Jr., W.M. Hagler, Jr., J.F. Ort, and C.K. Henrikson.
1993.Pancreatic splenic lobe organ culture system: Viability and amylase release. J. Poultry Science. 72:185-192.