Effects of Elemental Mercury Vapor Inhalation on Arterial Blood Gases, Lung Histology, and Interleukin-1 Expression in Pulmonary Tissues of Rats.

Liqaa A Raffee,Nadeem Alabdallah,Khaled Z Alawneh,Ruba A Alassaf,Musa A Alshehabat,Abdallah Alzoubi,Abdel-Hameed Al-Mistarehi

doi:10.1155/2021/4141383

Liqaa A Raffee, Nadeem Alabdallah + Show 5 more

Open Access

https://doi.org/10.1155/2021/4141383

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Abstract

We investigated the effects of elemental mercury vapor inhalation on arterial blood gases (ABGs), lung histology, and interleukin-1 (IL-1) expression in pulmonary tissues in rats. A total of 42 Sprague Dawley rats were divided randomly into three groups. Rats in the first group were used as the control (CG). A short-term group (STG) and a long-term group (LTG) were exposed to 500 μg/m3 of mercury vapor 2 hrs/day for 21 days and 65 days, respectively. After exposure periods were completed, arterial blood samples were obtained, and ABGs were measured. Lung tissue sections were prepared for histology evaluation and immune-stained to detect IL-1 expression. There was a significant decrease in body weight in both STG (15%) and LTG (22%) compared with the CG. In the LTG, six out of 14 (43%) rats died, including two males and four females, while none of the rats in the STG died during the experiment. In both STG and LTG, a significant acid-base imbalance was characterized by a significant decrease in blood pH values and a significant increase in PCO2 values. Both PO2 and SpO2 blood values were significantly decreased in the STG and LTG, while no changes were observed in HCO3 values in all groups. Histological evaluation of lung tissues revealed severe lesions characterized by pulmonary emphysema and inflammatory cellular infiltrate. IL-1 expression in lung tissues was not significantly different between exposed rats and control subjects. These results indicate significant alterations in blood acid-base status characterized by severe respiratory acidosis with hypoxemia and no evidence of compensatory alkalosis in rats after exposure to short- and long-term elementary mercury vapor.

Highlights

Mercury is a highly toxic heavy metal with significant public health and safety implications worldwide [1,2,3,4,5]
Results were obtained for arterial blood gases (ABGs), a histological study of rats’ lung tissues, immunohistochemical analysis of rats’ lung tissues, and an animal well-being assessment based on animal weight and mortality
Results are reported in Figure 1. e percentages of body weight loss were 15% and 22% in the short-term group (STG) and long-term group (LTG), respectively. e control group (CG) and STG subjects all survived the course of the study

Summary

Introduction

Mercury is a highly toxic heavy metal with significant public health and safety implications worldwide [1,2,3,4,5]. E pathogenesis of mercury poisoning is often multifaceted as it manifests in many forms and can impact all body systems depending on the underlying pathways and enzymes affected. Acute severe exposure to elemental mercury vapor has been reported to lead to fatality as a result of pulmonary insufficiency and acute renal failure [21]. No recent scientific reports are documenting the effects of exposure to elementary mercury vapor on various blood gas parameters and underlying pulmonary lesions that might explain possible acid-base alterations associated with inhalation of mercury vapor. Erefore, this study was designed to investigate the toxic effects of elemental mercury vapor on various arterial blood gas parameters and determine the possible underlying pulmonary pathology that might lead to acid-base alterations using Sprague Dawley rats. A preliminary preprint version of this scientific article was published before peer review on the Research Square website [25]

Materials and Methods

Results

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