Effects of Formaldehyde on Respiratory Mucosa in Rats

Abstract

SUMMARY:Formaldehyde inhalation, are known to be nasal mucosa irritating feature. This study we are examined the effects histopathologic of formaldehyde inhalation on rats by using light microscopy. 16 adult wistar albino rats were used in this study. 8 rats were in control group and 8 rats were in experiment group. Experiment group was exposed to 10 ppm formaldhyde 8hours/day,5days/ week for 8 week. Nasal mucosa was removed and placed in 10% formaline. Sections were stained with Hematoxylene-Eosine and observed under light microscopy. The lining epithelium of respiratory mucosa showed a loss of ciliated cells with metaplasia of goblet cells and hyperplasia of squamous cells.

Histopathologic Changes in Rat Organs Upon Chronic Exposure to Formaldehyde Vapor

“…10 The current study investigated that exposure to concentrated formaldehyde for 5hours/day (15 days) had an irritating effect especially on the respiratory organs (lung and trachea); this finding is in agreement with Cui et al, 11 who mentione respiratory system is the major target of formaldehyde. The tracheal and pulmonary changes in this study as dysplasia, metaplasia, infiltration of mononuclear inflammatory cells and tracheal gland hyperplasia, desquamated epithelium, of alveolar septa, congestion of blood vessels and interstitial fibrosis are consistent with a number of previous studies at a variable dosage of formaldehyde period of exposure and the observations were; two previous studies on respiratory ed loss of the cilia, squamous metaplasia and infiltration of mononuclear inflammatory cells in Wistar rats, 12,13 congestion and squamous metaplasia were observed by Rusch et al, 14 in the nasal turbinate of monkey and showed mononuclear cellular infiltrations, emphysema, loss of mucosal folds and hyperplasia of cells in the bronchiole, peribronchial lymphomononuclear cellular infiltration and congestion and haemorrhages in the respiratory organs of rabbit after exposure to formaldehyde vapor. Also reported squamous cell metaplasia of trachea, thickening alveolar septum, bronchiolar epithelial hyperplasia, proliferative capillary, pulmonary vasculitis, hyperplastic parabronchiloar lymphocytic aggregations, pulmonary fibrosis and SIS Impact Factors:0.792 ,ISI Impact Factor:3.259 view of rat skin in the control group (H&E stains, X40, X100 and X400 respectively), and D: Focal epidermal hyperplasia Formaldehyde is recognized as toxic at certain doses and the chances of 9 The toxicity of formaldehyde is of concern to all who work closely with it.…”

“…6 In rats which were exposed to 10 ppm formaldehyde inhalation 8 hours/day, 5 days/week for 8 weeks, the lining epithelium of respiratory mucosa showed a loss of ciliated cells with metaplasia of goblet cells. 7 Rats inhaled 20.3 ppm formaldehyde gas for 13 weeks, 8 hours/day, 5 days a week, induced a variety of toxic effects in the liver tissue such as hepatic enlargement, hepato-cellular fatty degeneration and hepatic necrosis. 8 An experiment study on rat kidney showed that rat exposure to formaldehyde vapor in the concentration of 1.5 ppm 4 hours/day, for 4 days/week for 18 weeks led to mild congestion in the glomeruli, focal congestion and vacuolar (hydropic) degeneration of tubular cells, and necrosis.…”

Clinical, Radiographical and Histopathological Evaluation of Amniotic Membrane Allograft Pulpotomy in Primary teeth

“…Neither 1 month nor 3 months intervals showed any signs of reparative dentiongenesis. These findings are comparable to those obtained by Talaat et al (71) , El-Meligy et al (72) and Yorgancilar et al (73) who found that the formaldehyde within FC has an irritating effect that increases the infiltration of lymphomononuclear cells within the dental pulp. This augments dental pulp inflammatory responses that, in turn, stimulate the differentiation of odontoclasts and death of odontoblasts, which initiates internal inflammatory dentinal resorption and failure of dentin bridge formation, respectively (74)(75)(76) .…”

Effects of formaldehyde on vascular endothelial growth factor, matrix metallopeptidase 2 and osteonectin levels in periodontal membrane and alveolar bone in rats

“…In a study of Bansal et al [5] on rabbits, it was stated that even the short term exposure (6 weeks) of concentrated vapours of formaldehyde (40% solution) cause an irritant effect on the respiratory tract and alters its functional activity and cellular morphology. Cell proliferation is increased by 5 days of inhalation at 6 ppm formaldehyde and microarray analysis shows the expression of 15 genes were altered by 5 days of inhalation at 2 ppm formaldehyde [33].…”

“…Yorgancilar et al [33] reported that inhalation of formaldehyde resulted in nasal mucosa and connective tissue inflammation, as well as other structures in the nasal cavity, which may increase rhinitis. In our study, remarkably increased inflammation in the maxillary region, altered fibrous structure in the periodontal region and developed cellular infiltration were observed.…”