Toxicokinetic and Genotoxicity Study of NNK in Male Sprague-Dawley Rats Following Nose-Only Inhalation Exposure, Intraperitoneal Injection, and Oral Gavage

Author(s):  
Shu-Chieh Hu ◽  
Matthew S Bryant ◽  
Estatira Sepehr ◽  
Hyun-Ki Kang ◽  
Raul Trbojevich ◽  
...  

Abstract The tobacco-specific nitrosamine NNK [4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone] is found in tobacco products and tobacco smoke. NNK is a potent genotoxin and human lung carcinogen; however, there are limited inhalation data for the toxicokinetics (TK) and genotoxicity of NNK in vivo. In the present study, a single dose of 5x10−5, 5x10−3, 0.1, or 50 mg/kg body weight (BW) of NNK, 75% propylene glycol (vehicle control), or air (sham control) was administered to male Sprague-Dawley (SD) rats (9-10 weeks age) via nose-only inhalation (INH) exposure for 1 hour. For comparison, the same doses of NNK were administered to male SD rats via intraperitoneal (IP) injection and oral gavage (PO). Plasma, urine, and tissue specimens were collected at designated timepoints and analyzed for levels of NNK and its major metabolite 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanol (NNAL) and tissue levels of DNA adduct O6-methylguanine by LC/MS/MS. TK data analysis was performed using a non-linear regression program. For the genotoxicity subgroup, tissues were collected at 3 hours post-dosing for comet assay analysis. Overall, the TK data indicated that NNK was rapidly absorbed and metabolized extensively to NNAL after NNK administration via the three routes. The IP route had the greatest systemic exposure to NNK. NNK metabolism to NNAL appeared to be more efficient via INH than IP or PO. NNK induced significant increases in DNA damage in multiple tissues via the three routes. The results of this study provide new information and understanding of the toxicokinetics and genotoxicity of NNK.

2019 ◽  
Vol 2019 ◽  
pp. 1-8
Author(s):  
Weina Ma ◽  
Lei Lv ◽  
Jungang Guo ◽  
Yongjun Meng ◽  
Yinghua Wang ◽  
...  

The aim of this study was to examine whether Xuesaitong, a multiherbal formulation for coronary heart disease, alters the pharmacokinetics of losartan. Adult male Sprague Dawley rats randomly received losartan (10 mg/kg) or losartan plus Xuesaitong (10 mg/kg) through an oral gavage (n = 6). Multiple blood samples were obtained for up to 36 h to determine the concentrations of losartan and its active metabolite, EXP3174, through ultraperformance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS). Pharmacokinetics were estimated using a noncompartmental model. The half-life (t1/2) of losartan was decreased by Xuesaitong (4.26 ± 1.51 vs. 6.35 ± 2.10 h; P<0.05). The apparent volume of distribution (Vd) of losartan was also decreased by the combination of losartan and Xuesaitong (4.41 ± 1.61 vs. 7.20 ± 2.41 mL; P<0.05). The time to maximum concentration (Tmax) of losartan was increased by Xuesaitong (1.06 ± 1.04 vs. 0.13 ± 0.05 h; P<0.05). Xuesaitong also decreased the t1/2 of EXP3174 (8.22 ± 1.41 vs. 6.29 ± 1.38 h; P<0.05). These results suggest that there is a complex interaction between losartan and Xuesaitong. In addition to enhanced elimination of losartan and EXP3174, Xuesaitong may also decrease the absorption rate and Vd of losartan.


2020 ◽  
Vol 36 (1) ◽  
Author(s):  
Nam Hee Youn ◽  
Eun Ji Kim ◽  
Jung-Sun Yi ◽  
Joo Hwan Kim ◽  
Ye-Jin Cho ◽  
...  

AbstractSome drugs cause phototoxicity in humans when exposed to light, thus there is a need for an in vivo phototoxicity test to evaluate them. However, an in vivo phototoxicity test method to evaluate this has not been established. This study aimed to establish an in vivo phototoxicity test method for transdermally administered drugs. For this, we evaluated the phototoxicity using Sprague-Dawley (SD) rats for transdermal administered drugs and we studied the appropriate UVA dose using 8-methoxypsalen, which is a well-known phototoxic drug. We found that a UVA dose of 15 J/cm2 was dose and time dependent response compared to other UVA doses. We performed the Minimum Erythema Dose (MED) test because UVB can cause skin irritation by itself and selected 0.01 J/cm2 as an appropriate dose of UVB. Using the selected UVA and UVB doses, we performed a phototoxicity study of 6 pharmaceutical drugs, which included phototoxic and non-phototoxic drugs. As a result of the phototoxicity test, 100% accuracy was obtained when compared with previous studies. In addition, we performed histopathology to confirm the new findings. We found that histopathology can be used as an additional indicator of phototoxicity test for transdermally administered drugs.


2021 ◽  
Vol 7 (1) ◽  
Author(s):  
Himanshu Kushwah ◽  
Nidhi Sandal ◽  
Meenakshi Chauhan ◽  
Gaurav Mittal

Abstract Background Uncontrolled bleeding is one of the primary reasons for preventable death in both civilian trauma and military battle field. This study evaluates in vitro and in vivo hemostatic potential of four biopolymeric natural gums, namely, gum tragacanth, guar gum, xanthan gum, and gum acacia. In vitro evaluation of whole blood clotting time and erythrocyte agglutination assay were carried out. In vitro cytotoxicity studies with respect to each gum were done in human lymphocytes to ascertain percent cell viability. In vivo hemostatic potential of each gum (as sponge dressing and powder form) was evaluated in Sprague Dawley rats using tail bleeding assay and compared with commercially available hemostatic sponge. Other important parameters like (a) time taken for complete hemostasis, (b) amount of blood absorbed, (c) adherence strength of developed hemostatic dressing(s), (d) incidence of re-bleeding, and (e) survival of animals were also studied. Results Of the four test gums studied, xanthan gum (@3mg/ml of blood) and gum tragacanth (@35mg/ml of blood) were able to clot blood in least time (58.75±6.408 s and 59.00±2.082 s, respectively) and exhibited very good hemostatic potential in vitro. Except for xanthan gum, all other test gums did not exhibit any significant cytotoxicity at different time points till 24 h. In rat tail bleeding experiments, gum tragacanth sponge dressing and powder achieved hemostasis in least time (156.2±12.86 s and 76±12.55 s, respectively) and much earlier than commercially available product (333.3±38.84 s; p˂0.01). Conclusion Results indicate potential of gum tragacanth to be developed into a suitable hemostatic product.


1991 ◽  
Vol 7 (3) ◽  
pp. 125-139 ◽  
Author(s):  
David R. Bevan ◽  
David M. Ruggio

To evaluate health risks associated with exposure to particulates in the environment, it is necessary to quantify the bioavailability of carcinogens associated with the particulates. Direct analysis of bioavailability in vivo is most readily accomplished by adsorbing a radiolabeled form of the carcinogen to the particulate. A sam ple of native diesel particulate collected from an Oldsmobile die sel engine that contained 1.03 μ g benzo[ a] pyrene ( BaP)/ g particulate was supplemented with exogenous [ 3 H]- BaP to pro duce a particulate containing 2.62 μ g BaP/g. To insure that elu tion of BaP from native and [3 H] -BaP-supplemented particulate was similar, in vitro analyses were performed. When using phos pholipid vesicles composed of dimyristoylphosphatidylcholine (DMPC), 1.52% of total BaP was eluted from native particulate into the vesicles in 18 hrs; from [ 3 H] -BaP supplemented particu late, 1.68% was eluted. Using toluene as eluent, 2.55% was eluted from native particulate, and 8.25% from supplemented particulate, in 6 hrs. Supplemented particulate was then instilled intratracheally into male Sprague-Dawley rats and distribution of radioactivity was analyzed at selected times over 3 days. About 50% of radioactivity remained in lungs at 3 days following instil lation, with 30% being excreted into feces and the remainder dis tributed throughout the organs of the rats. To estimate the amount of radioactivity that entered feces through swallowing of a portion of the instilled dose, [3 H] -BaP-supplemented particu late was instilled intratracheally into rats that had a cannula sur gically implanted in the bile duct. Rate of elimination of radio activity into bile was monitored; 10.6% of radioactivity was re covered in 6 hr, an amount slightly lower than the 12.8% ex creted in 6 hrs into feces of animals with intact bile ducts. Our studies provide a quantitative description of the distribution of BaP and its metabolites following intratracheal instillation of diesel particulate. Because rates of elution of BaP in vitro are similar for native diesel particulate and particulate with supple mental [ 3H] -BaP, our results provide a reasonable estimate of the bioavailability in vivo of BaP associated with diesel particu late.


2016 ◽  
Vol 3 (4) ◽  
pp. 167-175 ◽  
Author(s):  
Jiang Pu ◽  
Yuanyuan Deng ◽  
Xiaoyan Tan ◽  
Gaofeng Chen ◽  
Cong Zhu ◽  
...  

2012 ◽  
Vol 303 (8) ◽  
pp. R850-R860 ◽  
Author(s):  
Miriam Goebel-Stengel ◽  
Andreas Stengel ◽  
Lixin Wang ◽  
Gordon Ohning ◽  
Yvette Taché ◽  
...  

Various molecular forms of CCK reduce food intake in rats. Although CCK-8 is the most studied form, we reported that CCK-58 is the only detectable endocrine peptide form in rats. We investigated the dark-phase rat chow intake pattern following injection of CCK-8 and CCK-58. Ad libitum-fed male Sprague-Dawley rats were intraperitoneally injected with CCK-8, CCK-58 (0.6, 1.8, and 5.2 nmol/kg), or vehicle. Food intake pattern was assessed during the dark phase using an automated weighing system that allowed continuous undisturbed monitoring of physiological eating behavior. Both CCK-8 and CCK-58 dose dependently reduced 1-h, dark-phase food intake, with an equimolar dose of 1.8 nmol being similarly effective (−49% and −44%). CCK-58 increased the latency to the first meal, whereas CCK-8 did not. The intermeal interval was reduced after CCK-8 (1.8 nmol/kg, −41%) but not after CCK-58. At this dose, CCK-8 increased the satiety ratio by 80% and CCK-58 by 160%, respectively, compared with vehicle. When behavior was assessed manually, CCK-8 reduced locomotor activity (−31%), whereas grooming behavior was increased (+59%). CCK-58 affected neither grooming nor locomotor activity. In conclusion, reduction of food intake by CCK-8 and CCK-58 is achieved by differential modulation of food intake microstructure and behavior. These data highlight the importance of studying the molecular forms of peptides that exist in vivo in tissue and circulation of the animal being studied.


2011 ◽  
Vol 186 (1) ◽  
pp. 835-841 ◽  
Author(s):  
Xuemei Chen ◽  
Hui An ◽  
Lin Ao ◽  
Lei Sun ◽  
Wenbin Liu ◽  
...  

2012 ◽  
Vol 27 (5) ◽  
pp. 301-305 ◽  
Author(s):  
Baohua Zhu ◽  
Chuanming Tong ◽  
Weitao Guo ◽  
Rong Pu ◽  
Guoping Zhang ◽  
...  

PURPOSE: To investigate synergistic suppression of donor liver pre-perfusion with recipient serum (RS) and cobra venom factor (CVF) treatment on hyperacute rejection (HAR) following liver xenotransplantation. METHODS: Guinea-pigs (GP, n=24) and Sprague-Dawley rats (SD, n=24) were recruited. Before transplantation, serum was collected from SD rats and used for preparation of inactivated complements. GP and SD rats were randomly assigned into four groups (n=6), respectively: RS group, CVF group, RS+CVF group and control group. Orthotopic liver xenotransplantation was performed with modified two-cuff technique. The survival time and liver function of recipients, morphological and pathological changes in rat livers were investigated. RESULTS: There was no piebald like change in the recipient livers in all experiment groups. The survival time of recipients in all experiment groups was longer than that in control group (p<0.05). Moreover, the survival time in the RS+CVF group was markedly longer than that in the RS group (p<0.01) and CVF group (p<0.05). The serum ALT level in all experiment groups were lower than that in the control group (p<0.05). Furthermore, the ALT level in the RS+CVF group was significantly lower than that in the CVF group (p<0.05) and RS group (p<0.01). The histological damages were significantly improved when compared with the control group, and the histological damages in the RS+CVF group were milder than those in the remaining groups (p<0.05) CONCLUSION: Pre-perfusion of donor liver with recipient serum and cobra venom factor treatment can exert synergistic suppressive effects on the hyperacute rejection following liver xenotransplantation.


2000 ◽  
Vol 88 (3) ◽  
pp. 1036-1042 ◽  
Author(s):  
Peter A. Farrell ◽  
Jazmir M. Hernandez ◽  
Mark J. Fedele ◽  
Thomas C. Vary ◽  
Scot R. Kimball ◽  
...  

Translational control of protein synthesis depends on numerous eukaryotic initiation factors (eIFs) and we have previously shown ( Am. J. Physiol. Endocrinol. Metab. 276: E721–E727, 1999) that increases in one factor, eIF2B, are associated with increases in rates of protein synthesis after resistance exercise in rats. In the present study we investigated whether the eIF4E family of initiation factors is also involved with an anabolic response to exercise. Male Sprague-Dawley rats either remained sedentary ( n = 6) or performed acute resistance exercise ( n = 6), and rates of protein synthesis were assessed in vivo 16 h after the last session of resistance exercise. eIF4E complexed to eIF4G (eIF4E ⋅ eIF4G), eIF4E binding protein 1 (4E-BP1) complexed to eIF4E, and phosphorylation state of eIF4E and 4E-BP1 (γ-form) were assessed in gastrocnemius. Rates of protein synthesis were higher in exercised rats compared with sedentary rats [205 ± 8 (SE) vs. 164 ± 5.5 nmol phenylalanine incorporated ⋅ g muscle−1 ⋅ h−1, respectively; P < 0.05]. Arterial plasma insulin concentrations were not different between the two groups. A trend ( P = 0.09) for an increase in eIF4E ⋅ eIF4G with exercise was noted; however, no statistically significant differences were observed in any of the components of the eIF4E family in response to resistance exercise. These new data, along with our previous report on eIF2B, suggest that the regulation of peptide chain initiation after exercise is more dependent on eIF2B than on the eIF4E system.


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