Electrophysiological and Histopathological Evaluation of Respiratory Tract, Diaphragm, and Phrenic Nerve After Dichlorvos Inhalation in Rats

Abstract

The aim of this study was to investigate the dose-related effects of dichlorvos inhalation on electrophysiological alterations of diaphragm and phrenic nerve and the changes in the histologic structure of respiratory system. This study was performed on 33 rats divided into 5 groups, inhaling 1, 2, 5, 10, and 15 microg/L of dichlorvos, respectively. Electrodiagnostic investigations of diaphragm and phrenic nerve were made before and after inhalations. Aspiration samples were taken from lungs to evaluate the presence of infection agents. The airways, lungs, and diaphragms were dissected out for histologic investigation. Rats exposed to a low concentration of dichlorvos (1-5 microg/L) showed no symptoms of intoxication, but exposure to higher doses (10-15 microg/L) induced dyspnea in several animals. Lower doses of dichlorvos revealed no electromyographic changes on diaphragm, whereas higher doses revealed a clear neuropathic involvement. Delayed phrenic nerve motor conduction velocity was noted for each group (p <.05). Morphologic changes on the tracheal epithelium, hyperplasia, thickening of the blood-air barrier, degeneration in alveoli, and ductus alveolaris were seen in histopathologic investigation. In conclusion, the acute inhalation of dichlorvos caused clear evidence of neuropathic involvement of the diaphragm and the phrenic nerve. Also, toxic pneumonitis and injury to the tracheal epithelial were noticed.

Sepsis induces early phrenic nerve neuropathy in rats

“…Phrenic nerve conduction study Electrophysiological recordings (Biopac-MP 100; Biopac, Santa Barbara, CA, USA) were performed as described previously [11]. The active and reference surface Ag/AgCl disc electrodes were used to record the phrenic nerve compound action potential (CMAP) using the modified MACLEAN and MATTIONI [12] technique.…”

Technetium-99mdiethylenetriaminepentaacetic acid radioaerosol scintigraphy in organophosphate induced pulmonary toxicity: Experimental study

“…Yurumez et al (19) showed that there was alveolar congestion, hemorrhage, neutrophil infiltration or aggregations in the vascular walls or air spaces in the animals treated with OP compounds. In another study, Atis et al (7) reported that morphologic changes on the tracheal epithelium, hyperplasia, thickening of the blood-air barrier, degeneration in the alveoli, and ductus alveolaris were seen in histopathologic investigation after dichlorvos inhalation in rats. In our study, we observed similar findings with these studies, such as intraparenchymal vascular congestion and thrombosis, intraparenchymal hemorrhage, respiratory epithelial proliferation, increased number of macrophages in the alveolar and bronchial lumen, alveolar destruction, emphysematous changes, and bronchoalveolar hemorrhage.…”

“…Presence of respiratory failure suggests a poor prognosis. Morphologic changes in the tracheal epithelium, hyperplasia, thickening of the alveolar-capillary membrane, degeneration in alveoli and alveolar ducts are seen on histopathologic investigation (4,7).…”

Planning Experimental Studies and Selection of an Available Animal Model?

“…There were four animal models used: (i) Induced Models, (ii) Spontaneous models, (iii) Negative Models, and (iv) Orphon Models. As a result, the selected animal model, no matter what the model is, should be very well defined.key words: Experimental study, animal study, model, planning GiriŞ Deneysel araştırma, herhangi bir konuyu aydınlatmak, bir soruna çözüm getirmek, belirli kavramlara, kuramlara ya da yasalara ulaşabilmek için yapılan planlı ve bilimsel bir çalışma olarak tanımlanabilmektedir [1,2].Deneysel tıp araştırmalarında hayvanların kullanımı, özellikle farmasötik gelişmeler ve moleküler yolak çalışmalarında oldukça yaygındır [3][4][5][6].Deneysel araştırmaların 4 safhası vardır [7][8][9][10][11][12] …”

“…Araştırma planı, bağımlı ve bağımsız değişkenler arasındaki ilişkileri test etmek için düzenlenir. Bu planda hangi gözlemlerin ve işlemlerin yapılacağı, nasıl yapılacağı, bunların nasıl değerlendirileceği gibi bilgiler bulunmalıdır [7][8][9][10][11][12].…”