New Findings Concerning Eosinophilic Substance Deposition in Mouse Nasal Septum

Abstract

An eosinophilic substance (ES) is usually observed in the mouse nasal septum. In contrast to textbooks and one report describing ES as amyloid, a previous study by the authors revealed that ES is not amyloid but consists of collagen and an amorphous material. Furthermore, it was suggested that the amorphous material was produced by clear HE-stained nasal gland epithelial cells present at the dorsal portion directly above the vomeronasal organ. In this histological examination, ES deposition showed sex difference (more intense in males than in females). ES increased with age but not in seniles, suggesting that the increase has a limit. In the detailed examination using subserial HE-stained nasal sections, it was revealed that the clear HE-stained nasal glands continued to the vomeronasal glands, which communicated with the lumen of the vomeronasal organ, and the vomeronasal gland epithelial cells contained strongly periodic acid-Schiff (PAS) positive granules, similar to the clear HE-stained nasal gland epithelial cells. ES also deposited in the interstitium of the vomeronasal glands. The results suggested a possibility that ES deposition may be related to vomeronasal organ.

Proceedings of the 2013 Joint JSTP/NTP Satellite Symposium

“…Similar lesions were previously diagnosed as an “eosinophilic substance” 11 , 12 , 13 . The material was reported to be Congo red negative, pale blue with Masson’s trichrome and dark magenta with PAS.…”

“…After the presentation, there was discussion about whether or not to rename this lesion as “nasal septum hyalinosis,” since it has already been reported in the literature three times as “eosinophilic substance” by Doi et al 11 , 12 , 13 A revote resulted in nasal septum hyalinosis (48%), eosinophilic substance (46%), nasal gland proteinosis (3%), interstitial hyalinosis (2%), nasal gland secretion (2%), amyloid (0%) and others (0%). These voting results indicate that all audience members agreed that this lesion was not amyloid, although this is the diagnosis in the current INHAND document 14 .…”

Mouse

“…4.18). Doi et al (2010) have reported sex differences in the occurrence of eosinophilic substance in the nasal turbinates of B6C3F1 mice, with males showing a greater degree of deposition than females. Inflammatory changes in the turbinates occasionally occur in association with foreign bodies, infection or injury (Herbert & Leininger 1999) and may be associated with dysplastic dental changes encroaching into the nasal passages .…”

Proceedings of the 2010 National Toxicology Program Satellite Symposium

“…This lesion has been previously diagnosed as “eosinophilic substance” (ES) (Doi et al 2007, 2009, 2010). Present within the mouse nasal septum, it increases in volume with age (which plateaus over time), is more intense in males, and is not associated with degeneration or inflammation.…”