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Updated: Jul 27, 2026
Retroductal Submandibular Gland Instillation and Localized Fractionated Irradiation in a Rat Model of Salivary Hypofunction
Published on: April 24, 2016
Ultrastructural features of spironucleosis (hexamitiasis) in x-irradiated rat small intestine
Abstract:
An alteration in the host response to the intestinal protozoan Spironucleus (Hexamita) muris was noted in x-irradiated rat small intestine. When few were present in the crypt lumina, the intestinal microvillar border was normal. However, when larger numbers were present, the microvilli were greatly reduced in numbers or entirely absent in some regions. The organism was identified in the base of the crypt lumen, in apical portions of mucous cells, and near the basement membrane. Spironucleus enclosed by digestive vacuoles occasionally appeared to be in the process of being extruded through the basement membrane. Not all intracellular protozoa were surrounded by such digestive vacuoles. Spironucleus was never seen in association with the digestive vacuoles of Paneth cells. Since it has been suggested that Paneth cells have a role as a fixed phagocyte, ingesting protozoa and other microorganisms, the results presented here suggest that this function may have been impaired in irradiated animals.
Insights
X-irradiation impairs rat intestinal host response to Spironucleus muris. This protozoan causes microvillar damage and suggests impaired Paneth cell function in irradiated animals.
Area of Science:
- Gastroenterology
- Parasitology
- Radiation Biology
Background:
- The intestinal protozoan Spironucleus (Hexamita) muris can infect rodents.
- Paneth cells in the small intestine are hypothesized to play a role in innate immunity through phagocytosis.
Purpose of the Study:
- To investigate the host response to Spironucleus muris in the x-irradiated rat small intestine.
- To determine the effect of irradiation on the interaction between Spironucleus muris and intestinal epithelial cells, including Paneth cells.
Main Methods:
- Observation of Spironucleus muris within the small intestine of x-irradiated rats.
- Microscopic examination of intestinal morphology and cellular interactions.
Main Results:
- Spironucleus muris presence correlated with reduced or absent microvilli in the rat small intestine.
- The protozoan was found in crypt lumina, mucous cells, and near the basement membrane.
- Spironucleus muris was not observed within Paneth cell digestive vacuoles, suggesting impaired phagocytic function in irradiated animals.
Conclusions:
- X-irradiation alters the host response to Spironucleus muris in the rat small intestine.
- The findings suggest that Paneth cell phagocytic function may be compromised following irradiation, impacting the clearance of intestinal protozoa.
