In a continuing study of factors that regulate the operation of the lower esophageal sphincter, studies will be carried out in esophageal smooth muscle of opossums and cats. Isolated strips of muscle, 1 cm x 1 mm x 1 mm will be studied by electromicroscopy to seek distinguishing features of nerve and muscle morphology that will correlate with established physiological differences between muscle of the sphincter and that of the esophageal body. Similar morphologic correlations with the function of this muscle will be sought by a special method to examine the gross morphology of the intramural plexuses. The hypothesis will be examined that the sphincter muscle differs from the esophageal body muscle in respect to the source of calcium responsible for the tonic contraction of the sphincter and for the place of calmodulin in the calcium activation process for sphincteric tone.

Agency
National Institute of Health (NIH)
Institute
National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK)
Type
Method to Extend Research in Time (MERIT) Award (R37)
Project #
5R37DK011242-22
Application #
3482950
Study Section
Surgery and Bioengineering Study Section (SB)
Project Start
1977-01-01
Project End
1991-12-31
Budget Start
1988-01-01
Budget End
1988-12-31
Support Year
22
Fiscal Year
1988
Total Cost
Indirect Cost
Name
University of Iowa
Department
Type
Schools of Medicine
DUNS #
041294109
City
Iowa City
State
IA
Country
United States
Zip Code
52242
Fang, S; Thomas, R M; Conklin, J L et al. (1995) Co-localization of manganese superoxide dismutase and NADH diaphorase. J Histochem Cytochem 43:849-55
Christensen, J; Fang, S; Rick, G A (1995) NADPH-diaphorase-positive nerve fibers in smooth muscle layers of opossum esophagus: gradients in density. J Auton Nerv Syst 52:99-105
Conklin, J L; O'Meara, B W; Murray, J A et al. (1995) Effect of nitroblue tetrazolium on NO synthase and motor function of opossum esophagus. Dig Dis Sci 40:2390-7
Fang, S; Ledlow, A; Murray, J A et al. (1994) Vasoactive intestinal contractor: localization in the opossum esophagus and effects on motor functions. Gastroenterology 107:1621-6
Christensen, J; Rick, G A (1994) Interstitial cells of Cajal in the rat colon are damaged by mild hypoxia. J Auton Nerv Syst 48:175-80
Fang, S; Christensen, J (1994) Distribution of NADPH diaphorase in intramural plexuses of cat and opossum esophagus. J Auton Nerv Syst 46:123-33
Fang, S; Christensen, J; Conklin, J L et al. (1994) Roles of Triton X-100 in NADPH-diaphorase histochemistry. J Histochem Cytochem 42:1519-24
Christensen, J; Fang, S (1994) Colocalization of NADPH-diaphorase activity and certain neuropeptides in the esophagus of opossum (Didelphis virginiana). Cell Tissue Res 278:557-62
Christensen, J (1994) Defining the irritable bowel syndrome. Perspect Biol Med 38:21-35
Orvar, K B; Gregersen, H; Christensen, J (1993) Biomechanical characteristics of the human esophagus. Dig Dis Sci 38:197-205

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