vasoactive-intestinal-peptide and Intestinal-Diseases--Parasitic

We investigated the effects of an enteric infection with the parasitic nematode, Trichinella spiralis, on peptidergic and cholinergic neural pathways of the guinea pig jejunum. The content of the enteric neuropeptides, substance P (SP) and vasoactive intestinal peptide (VIP), and the activities of the key cholinergic enzymes, acetylcholinesterase (AChE) and choline acetyltransferase (ChAT), were measured and compared in extracts of jejunal muscularis externa (ME) obtained from uninfected jejunum and T. spiralis-inflamed jejunum. Significant decreases were detected in both SP immunoreactivity and AChE activity on days 6 and 10 postinfection (PI) in nematode-infected guinea pig jejunum compared to uninfected controls. The maximum changes observed for SP and AChE both occurred on day 10 PI and were evident as decreases of 37% and 48%, respectively, from the mean uninfected control values for SP and AChE. In contrast, VIP immunoreactivity and ChAT activity showed no significant changes during the enteric phase of T. spiralis infection. Nematode-evoked histopathological changes in jejunal tissues from infected animals were associated with significant increases in myeloperoxidase (MPO) activity, an index of inflammation intensity, which occurred on day 6 PI (885% of mean control) and day 10 PI (469% of mean control) coinciding temporally with the significant decrease in SP content and AChE activity during infection. Thus, intestinal motor disturbances observed in mammalian hosts during enteric nematode infections involve inflammation-generated changes in the neurohumoral control of smooth muscle function.

Topics: Acetylcholinesterase; Animals; Choline O-Acetyltransferase; Enteritis; Guinea Pigs; Intestinal Diseases, Parasitic; Jejunal Diseases; Jejunum; Male; Neuropeptides; Peroxidase; Substance P; Trichinella spiralis; Trichinellosis; Vasoactive Intestinal Peptide

A case of vasoactive intestinal polypeptide secreting ganglioneuroma associated with watery diarrhea and hypokalemia is presented. Diagnosis was delayed due to the presence of two parasitic infestations. After surgical removal of the tumor, the diarrhea resolved.

Topics: Adrenal Gland Neoplasms; Child, Preschool; Diarrhea; Female; Ganglioneuroma; Giardiasis; Humans; Intestinal Diseases, Parasitic; Trichomonas Infections; Vasoactive Intestinal Peptide

The neural and hormonal peptide content of rectal biopsy specimens from 10 patients with chronic autonomic failure, 10 patients with chronic gastrointestinal Chagas' disease, and 13 controls was studied with radioimmunoassay and immunocytochemistry. In the patients with Chagas' disease the mean concentrations of rectal vasoactive intestinal polypeptide, enteroglucagon, substance P, and somatostatin were all less than half of those in controls and in patients with chronic autonomic failure. Immunocytochemistry revealed a considerable reduction in the number and immunostaining of the peptide-containing cells and nerves. Concentrations of regulatory peptides in the rectum are thus reduced in association with intrinsic but not extrinsic autonomic neuropathy.

Topics: Autonomic Nervous System; Biopsy; Chagas Disease; Chronic Disease; Gastrointestinal Hormones; Humans; Intestinal Diseases, Parasitic; Nervous System Diseases; Rectum; Somatostatin; Substance P; Vasoactive Intestinal Peptide