Kidney Damage Following a 90-day Subchronic Inhalation Exposure to HTP Aerosol and Cigarette Smoke in Rats

Abstract

Abstract Cigarette smoking (CS) was reported to increase renal damage and the risk of kidney diseases. Heated tobacco product (HTP) was a new type of tobacco product, which contained lower harmful and potentially harmful constituents than cigarette and was reported a modified risk tobacco product to reduce exposure risk. Up to now, there are few studies on HTP, its health risk of kidneys is largely unknown. In our study subchronic inhalation toxicity of HTP aerosols and CS for 90 days was preformed to assess the health risk of kidney in rats. All the rats were randomly into sham, HTP (HTP_10, HTP_23, and HTP_50), and CS (Cig_23) groups and exposed using nose-only exposure system. After exposure, the blood, oxidative stress, biomarkers in early injury, apoptosis and histopathology of kidney were measured. The results showed that HTP and CS induced the increase of biomarkers including KIM-1, NGAL, and IL-18, oxidative stress and biochemical markers associated with of kidney function, while CS displayed more significant effect than CS on oxidative stress and creatinine and uric acid. Moreover, no obvious apoptosis and pathology of kidney were observed after HTP exposure and CS inhalation induced pathological damage only in male rats, which suggested that CS induced kidney damage in male rats in an un-dependent way with apoptosis and HTP exposure may cause no obvious pathological changes but along with in some biomarker abnormal. Overall, these results suggested that the health risks of HTP are significantly lower than those of cigarettes.