AJP - Gastrointestinal and Liver Physiology, Vol 250, Issue 4 546-G552, Copyright © 1986 by American Physiological Society
Pentagastrin on neurotransmitter enzyme activities in the rat gastrointestinal tract
M. M. Heitkemper and J. F. Shaver
The effects of three doses (5, 100, and 250 micrograms/kg) of pentagastrin
on the activities of choline acetyltransferase (ChAT) and acetylcholine
esterase (AChE), the neurotransmitter enzymes that synthesize and degrade
acetylcholine, and monoamine oxidase (MAO), the degradation enzyme for
catecholamines, were investigated. Enzyme activities were assayed in 6
gastrointestinal segments of 21- and 28-day-old and adult rats. All animals
were injected intraperitoneally for 7 days with pentagastrin, and the
results were compared with age-matched controls receiving saline for 7
days. Plasma and adrenal corticosterone levels were measured. No consistent
differences in adrenocortical variables existed between pentagastrin- and
saline-treated animals. Similarly, no consistent pentagastrin dose
responses of ChAT, AChE, and MAO activities were evident. However, at the
highest dose pentagastrin generally produced increases in ChAT activities
in 21- and 28-day-old rats, while producing decreases in AChE and MAO
activities in 21-day-old rats and increases in 28-day-old animals. There
were few significant differences in enzyme activities in adult rats
receiving pentagastrin as compared to saline.
