Administration Of Dibutyltin Dichloride Research Articles

Adipose‑derived mesenchymal stem cells ameliorate dibutyltin dichloride‑induced chronic pancreatitis by inhibiting the PI3K/AKT/mTOR signaling pathway.

Adipose-derived mesenchymal stem cells (ASCs) play a positive role in tissue injury repair and regeneration. The aim of this study was to determine whether ASCs could ameliorate chronic pancreatitis (CP) induced by the injection of dibutyltin dichloride (DBTC) and to elucidate its potential mechanisms. Furthermore, this study also explored whether there was a significant difference if the ASCs were injected via the inferior vena cava or the left gastric artery. CP was induced in rats by a single intravenous administration of DBTC, and the accumulation of collagen and apoptotic rates of pancreatic acinar cells were analyzed. According to the results, ASCs markedly reduced DBTC-induced pancreatic damage and collagen deposition in the rat model of CP. Moreover, ASCs significantly decreased pancreatic cell apoptosis by regulating the expression levels of caspase-3, BAX and Bcl-2. These effects were observed regardless of whether the injection was in the inferior vena cava or the left gastric artery. It was also found that the expression levels of phosphorylated PI3K, AKT and mTOR in pancreatic tissues of the DBTC-induced CP model group were significantly increased, while the expression levels of phosphorylated PI3K, AKT and mTOR in the two treatment groups were markedly decreased. ASCs noticeably suppressed the PI3K/AKT/mTOR pathway in the pancreatic tissue of DBTC-induced CP. This study indicated that ASCs protect against pancreatic fibrosis by modulating the PI3K/AKT/mTOR pathway, and have the potential to be a new strategy for the treatment of CP in the future.

Multiorgan chronic inflammatory hepatobiliary pancreatic murine model deficient in tumor necrosis factor receptors 1 and 2.

To provoke persistent/chronic multiorgan inflammatory response and to contribute to stones formation followed by fibrosis in hepatobiliary and pancreatic tissues. Tumor necrosis factor receptors 1 and 2 (TNFR1/R2) deficient mice reared in-house were given dibutyltin dichloride (DBTC) twice within 10 d by oral gavage delivery. Sham control animals received vehicle treatment and naïve animals remained untreated throughout the study. Animals were monitored daily for symptoms of pain and discomfort. The abdominal and hindpaw hypersensitivity were assessed with von Frey microfilaments. Exploratory behaviors were recorded at the baseline, after initiation of treatment, and before study termination. Histopathological changes were examined postmortem in tissues. Collagen accumulation and fibrosis were confirmed with Sirius Red staining. Animals lost weight after oral administration of DBTC and developed persistent inflammatory abdominal and hindpaw hypersensitivity compared to sham-treated controls (P < 0.0001). These pain related secondary mechanical hypersensitivity responses increased more than 2-fold in DBTC-treated animals. The drastically diminished rearing and grooming rates persisted after DBTC administration throughout the study. Gross as well as micropathology at one month confirmed that animals treated with DBTC developed chronic hepatobiliary injuries evidenced with activation of stellate cells, multifocal necrosis, fatty degeneration of hepatocytes, periportal infiltration of inflammatory cells, and prominent biliary ductal dilation. The severity of hepatitis was scored 3.7 ± 0.2 (severe) in DBTC-treated animals vs score 0 (normal) in sham-treated animals. Fibrotic thickening was extensive around portal ducts, in hepatic parenchyma as well as in lobular pancreatic structures and confirmed with Sirius Red histopathology. In addition, pancreatic microarchitecture was presented with distortion of islets, and parenchyma, infiltration of inflammatory cells, degeneration, vacuolization, and necrosis of acinar cells and distention of pancreatic ducts. Extent of pancreatic damage and pancreatitis were scored 3.6 ± 0.4 (severe) for DBTC-treated in contrast to score 0 (normal) in sham-treated animals. The gall bladder became expanded with ductal distention, and occasional bile stones were detected along with microscopic hepatic lesions. DBTC-treated animals developed splenic hypertrophy with increased weight and length (P < 0.01) along with thymic atrophy (P < 0.001). Finally, colitic lesions and colitis were prominent in DBTC-treated animals and scored 3.4 ± 0.3 (moderately severe) vs 0 (normal) for the sham-treated animals. This is the first report of chronic inflammatory multiorgan hepatobiliary pancreatitis, along with fibrosis and calculi formation induced reliably utilizing oral DBTC administration in TNFR1/R2 deficient mice.

Evidence of use: A selective COX-2 inhibitor in the treatment of experimental chronic pancreatitis induced by Dibutyltin dichloride

Abstract The search for new prophylactic and therapeutic drugs for the treatment of chronic pancreatitis (CP) is an urgent problem in current pancreatology. A promising direction in CP therapy may be the use of nonsteroidal anti-inflammatory drugs. Hence, the aim of the present study was to investigate the selective inhibition properties of COX-2 rofecoxib on the development of pancreas fibrosis in rats with experimental chronic pancreatitis induced by Dibutyltin dichloride (DBTC). The 60 male albino Wistar rats of our study were placed into three groups of 20 animals in each: I - the intact control; II - that which received an intraperitoneal injection (i.p.) of DBTC (6 mg/g); III - those which, 28 days after administration of DBTC (6 mg/g, i.p.), received a two-week course of treatment of rofecoxib (5 mg/kg, i.p). One day after rofecoxib treatment was completed, analysis was undertaken regarding the level of amylase, as well as the pancreatic amylase and lipase in the blood serum and the prostaglandin E2 in the pancreatic tissue. In addition, the morphological condition of the pancreas was ascertained. The obtained data suggest that administration of Rofecoxib reduces the development of fibrosis and improves the morpho-functional state of the pancreas in rats with chronic pancreatitis induced by DBTC. Thus, treatment with a selective COX-2 inhibitor could be a possible strategy for improving the clinical outcome of patients with CP.

Reduction of Fibrosis in Dibutyltin Dichloride–Induced Chronic Pancreatitis Using Rat Umbilical Mesenchymal Stem Cells From Wharton’s Jelly

The objective of this study was to investigate the effects of rat umbilical cord mesenchymal stem cells (UCMSCs) from Wharton's jelly on dibutyltin dichloride (DBTC)-induced chronic pancreatitis (CP) and subsequent pancreatic fibrosis in rats. A rat model of CP induced by DBTC was used. Male Sprague-Dawley rats were randomly divided into 4 groups: the control, DBTC, DBTC + UCMSCs, and control + UCMSC groups. Umbilical cord mesenchymal stem cells were administered intravenously on day 5 after the administration of DBTC. On days 14 and 28, the rats were evaluated morphologically and biochemically. The expression levels of inflammatory cytokines and chemokines in the pancreatic tissues of different groups were evaluated using quantitative real-time polymerase chain reaction. The activation of pancreatic stellate cells was estimated by immunochemistry and Western blot analysis of α-smooth muscle actin. Umbilical cord mesenchymal stem cells were detected in inflamed pancreatic tissues. Umbilical cord mesenchymal stem cell treatment improved the histological scores and alleviated the fibrosis of pancreas samples, The expression of cytokines in the DBTC + UCMSC group was significantly lower than that in the DBTC group. Also, pancreatic stellate cell activation was inhibited by UCMSC treatment. Xenogeneic transplantation of UCMSCs is a novel approach for the treatment of CP and subsequent fibrosis. Umbilical cord mesenchymal stem cells may be a promising therapeutic intervention for human CP in the future.

Effect of taurine on acinar cell apoptosis and pancreatic fibrosis in dibutyltin dichloride-induced chronic pancreatitis.

The relationship between pancreatic fibrosis and apoptosis of pancreatic acinar cells has not been fully elucidated. We reported that taurine had an anti-fibrotic effect in a dibutyltin dichloride (DBTC)-chronic pancreatitis model. However, the effect of taurine on apoptosis of pancreatic acinar cells is still unclear. Therefore, we examined apoptosis in DBTC-chronic pancreatitis and in the AR42J pancreatic acinar cell line with/without taurine. Pancreatic fibrosis was induced by a single administration of DBTC. Rats were fed a taurine-containing diet or a normal diet and were sacrificed at day 5. The AR42J pancreatic acinar cell line was incubated with/without DBTC with taurine chloramines. Apoptosis was determined by using terminal deoxynucleotidyl transferase-mediated dUTP-digoxigenin nick end labeling (TUNEL) assay. The expression of Bad and Bcl-2 proteins in the AR42J cells lysates was detected by Western blot analysis. The apoptotic index of pancreatic acinar cells in DBTC-administered rats was significantly increased. Taurine treatment inhibited pancreatic fibrosis and apoptosis of acinar cells induced by DBTC. The number of TUNEL-positive cells in the AR42J pancreatic acinar cell lines was significantly increased by the addition of DBTC. Incubation with taurine chloramines ameliorated these changes. In conclusion, taurine inhibits apoptosis of pancreatic acinar cells and pancreatitis in experimental chronic pancreatitis.

Developmental toxicity of dibutyltin dichloride given on three consecutive days during organogenesis in cynomolgus monkeys

We previously reported that the administration of dibutyltin dichloride (DBTCl) by nasogastric intubation during the entire period of organogenesis, days 20–50 of pregnancy, was embryolethal, but not teratogenic, in cynomolgus monkeys. The present study was conducted to further evaluate the developmental toxicity of DBTCl given to pregnant monkeys on 3 consecutive days during organogenesis. Cynomolgus monkeys were given DBTCl at 7.5 mg/kg body weight/day by nasogastric intubation on days 19–21, 21–23, 24–26, 26–28, 29–31, 31–33, or 34–36 of pregnancy, and the pregnancy outcome was determined on day 100 of pregnancy. Embryonic/fetal loss was observed in 1 female given DBTCl on days 19–21, 2 females given DBTCl on days 24–26, and 1 female given DBTCl on days 34–36. There were no effects of DBTCl on developmental parameters in surviving fetuses, including fetal body weight, crown-rump length, tail length, or placental weight. No external, internal, or skeletal malformations were detected in fetuses in any group. DBTCl did not affect the incidence of fetuses with skeletal variation or skeletal ossification of fetuses. These data confirm our previous findings that DBTCl was embryolethal, but not teratogenic, in cynomolgus monkeys.

Early pregnancy failure induced by dibutyltin dichloride in mice

In this study, we examined the adverse effects of dibutyltin on initiation and maintenance of pregnancy after maternal administration during early pregnancy in mice. Following successful mating, female ICR mice were given dibutyltin dichloride (DBTCl) at 0, 7.6, 15.2, or 30.4 mg/kg bw/day by gastric intubation on days 0-3 or days 4-7 of pregnancy. Female mice were sacrificed on day 18 of pregnancy, and the pregnancy outcome was determined. After administration of DBTCl on days 0-3, the rate of nonpregnant females and the incidence of preimplantation embryonic loss were significantly increased at 30.4 mg/kg bw/day. The incidences of postimplantation embryonic loss in females given DBTCl on days 0-3 at 15.2 mg/kg and higher and on days 4-7 at 7.6 mg/kg bw/day and higher were increased. No increase in the incidence of fetuses with external malformations was observed after the administration of DBTCl on days 0-3 or days 4-7. A decline in the serum progesterone levels was detected in mice given DBTCl at 30.4 mg/kg bw/day on days 0-3 or days 4-7 of pregnancy. The data show that DBTCl adversely affects the initiation and maintenance of pregnancy when administered during early pregnancy in mice and suggest that the decline in serum progesterone levels is responsible for pregnancy failure.

Suppression of decidual cell response induced by dibutyltin dichloride in pseudopregnant rats: as a cause of early embryonic loss

In our previous study, dibutyltin dichloride (DBTCl) caused preimplantation embryonic loss and postimplantation embryonic loss in rats following administration at 7.6 mg/kg and above on Days 0–3 and at 3.8 mg/kg and above on Days 4–7 of pregnancy, respectively. This study was designed to assess the effects of DBTCl on uterine function as a cause of early embryonic loss using pseudopregnant rats. DBTCl was given orally to pseudopregnant rats at 3.8, 7.6 or 15.2 mg/kg on pseudopregnant day (PPD) 0–3 or on PPD 4–7. The decidual cell response was induced by bilateral uterine scratch on PPD 4. The uterine weight on PPD 9 served as an index of uterine decidualization. Uterine weight and serum progesterone levels on PPD 9 were significantly decreased after administration of DBTCl at 7.6 mg/kg and above on PPD 0–3 and PPD 4–7. DBTCl had no effect on the serum estradiol levels and number of corpora lutea. Administration of progesterone reversed the suppression of uterine decidualization in rats given DBTCl on PPD 0–3. It can be concluded that DBTCl suppresses the uterine decidual cell response and decreases progesterone levels, and these effects are responsible for early embryonic loss due to DBTCl exposure.

Protective effects of progesterone on implantation failure induced by dibutyltin dichloride in rats

We previously showed that dibutyltin dichloride (DBTCl) at 7.6 mg/kg and higher on days 0–3 of pregnancy caused implantation failure and a decline in serum progesterone levels in rats and hypothesized that the decline is responsible for the implantation failure. This study was conducted to determine the protective effects of progesterone on the DBTCl-induced implantation failure in rats. Rats were given oral DBTCl at 0, 7.6, or 15.2 mg/kg on days 0–3 of pregnancy and/or subcutaneous progesterone at 2 mg/rat on days 0–8 of pregnancy. The reproductive outcome was determined on day 9 of pregnancy. No effects of administration of progesterone alone on the pregnancy rate and number of implantations were found. The pregnancy rate and number of implantations were significantly decreased after administration of DBTCl alone. The pregnancy rate and number of implantations were higher in the groups given DBTCl and progesterone than the groups given DBTCl alone. The present data indicate that progesterone protects, at least in part, against the DBTCl-induced implantation failure and support our hypothesis that the decline in progesterone levels is a primary mechanism for the implantation failure due to DBTCl.

Adverse effects of dibutyltin dichloride on initiation and maintenance of rat pregnancy

The present study was conducted to evaluate the adverse effects of dibutyltin dichloride (DBTCl) on initiation and maintenance of pregnancy after maternal exposure during early pregnancy in rats. After successful mating, female rats were given DBTCl by gastric intubation on Days 0 to 3 or on Days 4 to 7 of pregnancy at 0, 3.8, 7.6, or 15.2 mg/kg. Food-restricted pregnant rats were given an amount of feed equal to the feed intake of female rats treated with DBTCl at 15.2 mg/kg on Days 0 to 3 or on Days 4 to 7 of pregnancy. Female rats were sacrificed on Day 20 of pregnancy and pregnancy outcome was determined. After administration of DBTCl on Days 0 to 3, the rate of nonpregnant females and the incidence of preimplantation embryonic loss in the 7.6 mg/kg group were significantly higher than those in the control group, and those in the 15.2 mg/kg group were significantly higher than those in the control and pair-fed groups. In females with implantations, the numbers of implantations and live fetuses and the incidence of postimplantation embryonic loss in the groups given DBTCl on Days 0 to 3 were not significantly different from those in the control group. The incidence of postimplantation embryonic loss in the groups given DBTCl on Days 4 to 7 at 7.6 and 15.2 mg/kg was significantly higher than that in the control and pair-fed groups. It can be concluded that DBTCl adversely affects initiation and maintenance of pregnancy when administered during early pregnancy and that the manifestations of the adverse effects of DBTCl vary with the gestational stage at the time of maternal exposure.

The influence of ethanol on long-term effects of dibutyltin dichloride (DBTC) in pancreas and liver of rats.

The present study was done to determine the additional influence of daily ethanol intake (15% in drinking water ad libitum) on long-term toxic effects of a single administration of dibutyltin dichloride (DBTC, 8 mg/kg b.w. i.v.) in pancreas and liver of rats. Pathohistological changes in pancreas, bile duct and liver as well as pathobiochemical parameters of pancreatitis (amylase and lipase activity), liver lesions (alkaline phosphatase activity and bilirubin) and fibrosis (hydroxyproline and hyaluronic acid) were measured 1 day and 1 to 24 weeks after DBTC- and DBTC/ethanol administration. DBTC alone induced in rats an acute interstitial pancreatitis as well as acute bile duct and liver lesions in the early experimental phase. Later on, the acute inflammatory processes in pancreas and liver took a chronic course resulting in pancreatic fibrosis and liver cirrhosis. Ethanol increased the toxic effects of DBTC on pancreas and liver during the acute and chronic course. In the acute phase lasting 1 day to 2 weeks, ethanol enhanced the DBTC toxicity on acinar cell and bilio-pancreatic duct epithelium as well as the formation of obstructive ductal plugs by necrotic cell debris. The obstruction and cholestasis in the DBTC/ethanol-group were significantly stronger as in the DBTC-group. The significant increase of hydroxyproline in urine and hyaluronic acid in serum of the DBTC/ethanol treated rats after 12 to 24 weeks was connected with a more severe chronic inflammatory fibrosis in pancreas and liver in comparison to the DBTC-treated group.

An experimental model of hepatic fibrosis induced by the administration of dibutyltin dichloride

Dibutyltin dichloride (DBT) was investigated for its ability to induce hepatic fibrosis in rats. Since hydroxyproline does not appear in significant amounts in noncollagen protein and prolyl residues in collagen are not hydroxylated before they are in peptide-bound form, the conversion of isotopically labeled proline to hydroxyproline by prolyl hydroxylase was taken as one parameter reflecting the rate of collagen formation. In vitro collagen synthesis was determined by incubation of liver biopsies with labeled proline, after which incorporation of label into collagenase-digestible protein was compared to incorporation into collagenase-resistant protein. Hydroxyproline content served as a parameter of collagen accumulation. DBT, administered by oral intubation (10 and 20 mg/kg) daily for 4 days, produced inflammation in portal tracts and biliary damage at the end of this period. Prolyl hydroxylase activity was increased over control values in both treated groups, and in vitro collagen synthesis was increased in the higher dose group. DBT, administered by oral intubation (10 and 20 mg/kg) every other day for 12 days, produced extensive inflammation in portal tracts, biliary damage, fibrosis, necrosis, infarcted areas, and granulomatous lesions. In the higher dose group increases in hydroxyproline content, prolyl hydroxylase activity, and relative collagen synthesis in vitro were observed at the end of the 12-day period. DBT did not increase prolyl hydroxylase activity of L929 cells when added to culture media for 24 hr. These results suggest that DBT-induced fibrogenesis is a result of biliary damage and/or inflammatory processes rather than direct stimulation of fibroblasts.