Noise-induced gastric lesions: a light and electron microscopy study of the rat gastric wall exposed to low frequency noise

Abstract

-Context -Only a few studies evaluated the digestive alterations caused by low frequency noise (LFN) and most focused only on mucosal alterations. Objectives -To investigate the morphological injury of LFN-exposed gastric wall, beyond the epithelial layer. Methods -Wistar rats were exposed to low frequency noise (LFN), during increasing periods, 1 to 13 weeks. A control group was kept in silence. Gastric specimens were studied using: (i) light microscopy with hematoxylin-eosin and immunostaining for collagens; (ii) transmission electron microscopy; (iii) morphometry allowing statistical analysis. Results -Submucosa of all LFN-exposed animals exhibit increased thickness with fibrous proliferation. Transmission electron microscopy showed massive collagen deposition. Immunostaining identified collagen IV as responsible for the increased thickness. Morphometry allowed the demonstration of a significant difference of thickness between control and exposed groups. Vascular alterations included: i) intima proliferation and thickening, rupture of the internal elastic lamina, thrombotic changes; ii) thickening of the media; iii) after 9 weeks of LFN-exposure, we found new formed vessel presenting tortuous and twisted. There is a significant difference of arterial wall thickness between control and exposed groups. Conclusions -Deeper layers of gastric wall undergo alterations, including fibrosis of the submucosa caused by collagen IV deposition, an early marker of neoangiogenesis. Vascular alterations included thickening and thrombotic phenomena, but also images of newly formed vessels. This study suggests that, at least in the stomach, LFN-induced fibrosis could be linked with neoangiogenesis.

Effects of Noise Exposure on Systemic and Tissue-Level Markers of Glucose Homeostasis and Insulin Resistance in Male Mice

“…Beyond its effects on the auditory system, noise exposure has been associated with several adverse health outcomes, including hypertension, myocardial infarction, and impaired cognitive performance (Basner et al 2014; Cheng et al 2011; Cui et al 2012; Fonseca et al 2012). Thus, although the predominant concern with noise exposure is auditory damage, increasing attention has been paid to the nonauditory effects of noise.…”

Effects of high frequency noise on female rat′s multi-organ histology

“…Based on the Pascuan study, [9] noise exposure induced a decrease in corticosterone and catecholamines levels in BALB/c mice, which could seriously affect immune responses in susceptible individuals. In addition, studies of some other fi elds [10][11][12] have demonstrated that noise can increases collagen I and III in the extracellular matrix and induces ultrastructural alterations in the cardiomyocytes. Thus in this study, we conducted experiments to further evaluate the effect of noise on brain, heart, liver, and spleen by using experimental rats.…”

Noise rich in low frequency components, a new comorbidity for periodontal disease? An experimental study

“…[12] in the perivasculoductal connective tissue of the parotid gland, in which there is significant fibrosis and increase of collagen I and V in the connective tissue of the gland with exposure time, or to those reported by Fonseca et al ., that described fibrosis in the stomach and duodenum walls and the same behavior in collagens. [1016] Other organs such as vessels,[56] pericardium,[17] trachea,[18], or lungs,[19] have been shown to be affected by fibrosis when exposed. Ferreira et al .…”