Effects of Oral Nicotine on Rat Liver Stereology

Abstract

SUMMARY:Nicotine is the more abundant component in cigarette smoke. Because nicotine is first metabolized in the liver, our aim was to investigate the effects of nicotine on this organ by biochemical and stereological methods. Male Wistar rats were treated with oral nicotine (ON) diluted in drinking water during 32 days. The control group was treated with drinking water in the same period. Rats were sacrificed 24 hours after last day, the blood was collected and the liver was removed. Lipidogram was performed by enzymatic method and collagen fibers, fat globules and hepatocytes were count in the liver by stereological methods. We observed in control group preserved hepatocytes, with no presence of inflammatory cells. However in the ON group was possible to observe varied size of hepatocytes with cloudy cellular limits and histoarchitecture loss. Capillaries were fully of red blood cells. We observed also an increase of fat globules with small size. We observed in leucogram a reduction of leukocytes number (lymphocytes, neutrophils and monocytes) in the ON group in comparison to control group. The lipidogram showed an increase of triglycerides and total cholesterol for ON group when compared to control group. Moreover, a reduction of HDL-cholesterol was observed in ON group when compared to control group. Numerical density of hepatocytes was lesser in ON group when compared to control group. We suggest harmful effects of oral nicotine in liver induced by toxic mechanism with reduction of hepatocytes number and disturbance in lipid metabolism.

Maternal nicotine exposure leads to higher liver oxidative stress and steatosis in adult rat offspring

“…The chronic administration of nicotine also leads to deleterious effects in hepatic tissue. Adult Wistar rats treated daily for 10 days with 5 mg of nicotine in drinking water showed varied size of hepatocytes with different histoarchitecture; increase of fat drops in cytoplasm and reduction of hepatocyte number (Valenca et al, 2008). Liver lesions were also observed in pups of 10 days submitted to prenatal exposure to nicotine (4.3 ± 0.3 mg/kg/day at drinking water), demonstrating that during hepatic organogenesis, nicotine induced a hepatic focal necrosis in utero that persist for 10 days without reversion after nicotine withdrawal.…”

“…Thus, the NAFLD is correlated with decrease of antioxidant defenses (Conceição et al, 2013;Rolo et al, 2012;Videla et al, 2004). According to Valenca et al (2008), oral chronic nicotine exposure in adult rats is associated with impairment of lipid metabolism and microsteatosis. However, these authors did not investigate the oxidative status in this model.…”

The use of design‐based stereology to evaluate volumes and numbers in the liver: a review with practical guidelines

“…The second method is a modification introduced by Scherle (1970) over 40 years ago. It has been used in mouse (Karbalay-Doust & Noorafshan, 2009) and rat liver (Aguila et al 2003;Souza-Mello et al 2007;Valenca et al 2008;Halici et al 2009a,b). In the Scherle's method the organ is also fully immersed in fluid (of known density), but now suspended by a thin thread (care must be taken so that the liver does not touch the side or bottom of the container) -because the density of the used fluid is typically 1 (e.g.…”

What is Published in Human Morphology?: Types of Designs and Levels of Evidence

“…These methods are widely used in microscopic anatomy and development (Furrianca et al, 2008;Valenca et al, 2008;Vásquez & del Sol, 2009). Though the value of the delivered data is not reflected in the level of evidence that they provide, it cannot be concluded that studies that use stereology provide poor information.…”