Preponderance of inhibitory versus excitatory intramuscular nerve fibres in human chagasic megacolon

Jabari S, Da Silveira AB, De Oliveira E, Quint K, Neuhuber W, Brehmer A (2012)


Publication Status: Published

Publication Type: Journal article, Original article

Publication year: 2012

Journal

Publisher: Springer Verlag (Germany)

Book Volume: 27

Pages Range: 1181-1189

Journal Issue: 9

DOI: 10.1007/s00384-012-1500-0

Abstract

Introduction: Megacolon, chronic dilation of a colonic segment, is a frequent sign of Chagas disease. It is accompanied by an extensive neuron loss which, as shown recently, results in a partial, selective survival of nitrergic myenteric neurons. Here, we focused on the balance of intramuscular excitatory (choline acetyltransferase [ChAT]-immunoreactive) and inhibitory (neuronal nitric oxide synthase [NOS]- as well as vasoactive intestinal peptide [VIP]-immunoreactive) nerve fibres. Materials and methods: From surgically removed megacolonic segments of seven patients, three sets of cryosections (from non-dilated oral, megacolonic and non-dilated anal parts) were immunhistochemically triple-stained for ChAT, NOS and VIP. Separate area measurements of nerve profiles within the circular and longitudinal muscle layers, respectively, were compared with those of seven non-chagasic control patients. Additionally, wholemounts from the same regions were stained for NOS, VIP and neurofilaments (NF). Results: The intramuscular nerve fibre density was significantly reduced in all three chagasic segments. The proportions of inhibitory (NOS only, VIP only, or NOS/VIPcoimmunoreactive) intramuscular nerves were 68 %/58 % (circular/longitudinal muscle, respectively) in the controls and increased to 75 %/69 % (oral parts), 84 %/76 % (megacolonic) and 87 %/94 % (anal) in chagasic specimens. In the myenteric plexus, NF-positive neurons co-staining for NOS and VIP also increased proportionally. The almost complete lack of dendritic structures in ganglia of chagasic specimens hampered morphological identification. Discussion and conclusion: We suggest that preponderance of inhibitory, intramuscular nerve fibres may be one factor explaining the chronic dilation. Since the nerve fibre imbalance is most pronounced in the anal, non-dilated segment, other components of the motor apparatus (musculature, interstitial cells, submucosal neurons) have to be considered. © Springer-Verlag 2012.

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How to cite

APA:

Jabari, S., Da Silveira, A.B., De Oliveira, E., Quint, K., Neuhuber, W., & Brehmer, A. (2012). Preponderance of inhibitory versus excitatory intramuscular nerve fibres in human chagasic megacolon. International Journal of Colorectal Disease, 27(9), 1181-1189. https://doi.org/10.1007/s00384-012-1500-0

MLA:

Jabari, Samir, et al. "Preponderance of inhibitory versus excitatory intramuscular nerve fibres in human chagasic megacolon." International Journal of Colorectal Disease 27.9 (2012): 1181-1189.

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