Lack of correlation between villus and crypt damage in irradiated mouse intestine

Abstract

It has been observed that scanning electron microscopy is a more sensitive indicator of mucosal damage at low radiation dose levels than conventional quantitative crypt counting techniques. Three different fractionation schedules were subjected to investigation by both of these methods to try to elucidate some features of irradiation damage to the whole of the intestinal mucosa, at dose levels commonly used in clinical practice. Despite variations in the qualitative observations, there was a marked difference in two of the schedules between damage expressed as crypt counts and that described by the qualitative techniques. In the first case high crypt numbers were associated with severe mucosal damage, whereas the second schedule produced a reduced crypt count in association with low damage to the surface mucosa. A third schedule produced results in which there was a general agreement between low crypt numbers and considerable surface mucosal damage. However, observations were made of mucosal formations not previously seen on damaged mucosal surfaces. These resembled the appearance normally associated with the gut of patients suffering from coeliac disease. Variations in the qualitative observations were seen in all the schedules so that their interpretation in terms of perturbation of cellular kinetics is difficult.

Multinucleate giant enterocytes in small intestinal villi after irradiation

“…Twisted, bent and clumped villi were observed at higher doses and the villi often showed marked distortion of the tips, with indentations, blebs and 'warty' outgrowths. Similar villous abnormalities after different fractionated doses were reported by Carr et al (1979). The mucosal abnormalities reported in this last group of papers stemmed from experiments to examine the intestinal topographical morphology 34 days after irradiation, this timing being chosen to coincide with sampling for histological crypt counting (Withers & Elkind, 1970).…”

“…Friberg (1980) also studied rat mucosa but made no report of giant cells 5 days after radiation. Previous work on irradiated mouse mucosa (Carr & Toner, 1972;Carr et al, 1975Carr et al, , 1979Hamlet et al, 1976) all commented on the presence of 'warty' excrescences on the villi, some of which may well have been giant cells. It is possible that the giant enterocytes are found only in mouse gut recovering from radiation, or that they are more common here, and therefore more easily identified.…”

Scanning electron microscopy in biomedical research and routine pathology

“…Experimental radiation injury is a second model of mucosal response (Carr & Toner, 1972;Carr et al, 1975Carr et al, , 1979aHamlet et al, 1976). The lesion here is not localized, but diffuse, being expressed throughout the mucosal surface.…”