ผลกึ่งเรื้อรังของสารสกัดใบยาสูบ Nicotiana tabacum Linn. ต่อตับและไตของปลานิล Oreochromis niloticus Linn. / ดาราพร รินทะรักษ์ = Subchronic effects of nicotiana tabacum Linn. leaf extract on liver and kidney of tilapia Oreochromis niloticus Linn / Daraporn Rintarak
Histopathological alteration of tilapia Oreochromis niloticus Linn. Liver and kidney after long term exposure for 8 months to Nicotiana tabacum Linn. leaf extract was studied. Acute static toxicity tests were carried out on young tilapia at 1 month old for treatment and control groups, each group consists of 3 replication. The LC 50 at 96 hours was analyed by probit analysis, it was determined at 838.46 micro l/l. and from the application value, a sublethal concentration for subchronic toxicity test was calculated at 0.68 micro l/l. (nicotine content 0.034 mg/l) the subjects were exposed to this sublethal concentration for 8 months. The both sexes were randomly selected (n=30) in every month, the liver and kidney of treated and control groups were fixed and taken for conventional histological method and the liver was weighted. The comparative of the % reletive liver weight between treated and control group in the same month were determined. (P<=0.05). Results obtained showed that the histopathological alteration of liver at 1 month revealed sinusoid dilation and blood congestion, hydropic swelling of hepatocyte, hyaline droplet and fat vacuolation in cytoplasm of some hepatocyte. For 2 and 3 months exposure, the hepatocyte increased hyaline droplet and fat vacuolation, focal necrosis of peripancreatic hepatocyte and which near blood vessels, karyolysis and pyknosis of nucleus. There were macrophage invasion near inflammatory site. For 4 and 5 months exposure, fat vacuolation were change to severe. There were a large space of fat vacuole near pancreatic tissue, karyolysis, hyaline droplet and fat accumulation in acinar cells were determined. Macrophage invasion in both hepatocyte and acinar cell, Eosinophilic granular cells (EGCs) were found near blood vessels. For 6-7 months exposure, there were increased hepatocyte necrosis, perichromatin clumping and vacuolation in pancreas. Macrophage and EGCs invasion near inflammatory area. At 8 months of exposure, cyst were determined, blood congestion and macrophage invasion near cyst area. For histological change of kidney since 1-8 months, showed golmerulus contraction, especially, at 6-8 months of exposure. There were blood congestion and hydropic swelling of proximal tubules, hyaline droplet accumulation and fat vacuolation, tubular necrosis of proximal tubules. Since 2-8 months for exposure, were found macrophage invasion near inflammatory site and there were changed from mild to severe. At 8 months of exposure, there were found EGCs invasion inflammatory blood vessels. The severity of change were depended on the duration of treatment, it can be conclude that tobacco leaf extract caused subchronic effects on liver and kidney of tilapia.