This proposal contains new experiments to study the central and peripheral neural controls of colonic motility and defecation. Three extrinsic neural control systems will be studied. I. Sacral parasympathetic pathway. In vitro morphological (dye injection of neurons) electrophysiological pharmacological techniques and measurements of in vitro smooth muscle mechanical activity will be used. Studied with these techniques will be directed at central questions of: a) intrinsic neural factors which regulate the output from parasympathetic colonic neurons, b) morphological properties of parasympathetic neurons, c) effect of central preganglionic fibers and intrinsic gastrointestinal fibers on the spontaneous mechanical activity of smooth muscle, and d) the effect of polypeptides on synaptic transmission and electrophysiological properties of neurons in parasympathetic colonic ganglia and on the smooth muscle of the colon and rectum. II. Lumbar sympathetic pathway. In vitro morphological (dye injection, horseradish peroxidase technique), electrophysiological, pharmacological measurements and in situ measurements of colonic and urinary bladder motility will be used to determine the function and organization of postganglionic sympathetic neurons in lumbar sympathetic chain ganglia. Studies with these techniques will be directed to a) establishing the electrophysiological properties, synaptic transmission, responsiveness to polypeptides, and morphological characteristics of postganglionic sympathetic neurons which project to the abdominal viscera and b) determine the effects of the visceral postganglionic neurons on the smooth muscle of the colon and urinary bladder. III. Sacral motor pathway to the external anal sphincter. In situ electrophysiological, electromyographic and force measurements will be used to measure a) the contractile properties of the skeletal muscle fibers of the external anal sphincter and b) the smooth muscle of the rectum, internal anal sphincter and anal canal region.

Agency
National Institute of Health (NIH)
Institute
National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK)
Type
Research Project (R01)
Project #
5R01DK029920-08
Application #
3229123
Study Section
General Medicine A Subcommittee 2 (GMA)
Project Start
1981-08-01
Project End
1989-07-31
Budget Start
1988-09-01
Budget End
1989-07-31
Support Year
8
Fiscal Year
1988
Total Cost
Indirect Cost
Name
Michigan State University
Department
Type
Schools of Osteopathy
DUNS #
193247145
City
East Lansing
State
MI
Country
United States
Zip Code
48824
Kustasz, R; Helferich, W; Adams, T et al. (1997) A unique myosin isoform transition in cat striated external anal sphincter muscle induced by denervation. Am J Physiol 272:G698-704
Lin, J; Krier, J (1995) Human recombinant interleukin-1 beta inhibits nicotinic transmission in neurons of guinea pig pelvic plexus ganglia. Am J Physiol 269:G981-7
Venkova, K; Krier, J (1994) A nitric oxide and prostaglandin-dependent component of NANC off-contractions in cat colon. Am J Physiol 266:G40-7
Venkova, K; Milne, A; Krier, J (1994) Contractions mediated by alpha 1-adrenoceptors and P2-purinoceptors in a cat colon circular muscle. Br J Pharmacol 112:1237-43
Venkova, K; Krier, J (1993) Stimulation of lumbar sympathetic nerves evokes contractions of cat colon circular muscle mediated by ATP and noradrenaline. Br J Pharmacol 110:1260-70
Nishimura, T; Krier, J; Akasu, T (1993) Effects of vasoactive intestinal contractor on voltage-activated Ca2+ currents in feline parasympathetic neurons. Am J Physiol 265:G1158-68
McRorie, J; Krier, J; Adams, T (1991) Morphology and projections of myenteric neurons to colonic fiber bundles of the cat. J Auton Nerv Syst 32:205-15
Nishimura, T; Krier, J; Akasu, T (1991) Endothelin causes prolonged inhibition of nicotinic transmission in feline colonic parasympathetic ganglia. Am J Physiol 261:G628-33
Bielefeld, D R; Hume, J R; Krier, J (1990) Action potentials and membrane currents of isolated single smooth muscle cells of cat and rabbit colon. Pflugers Arch 415:678-87
Krier, J; Meyer, R A; Percy, W H (1989) Length-tension relationship of striated muscle of cat external anal sphincter. Am J Physiol 256:G773-8

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