In fetal development, organogenesis and functional developments are much influenced by xenobiotics administered during pregnancy or by maternal disease. In rat, while the critical periods for the morphological abnormalities during development are
days
11-14 of gestation, those of functional defects are days 18-22. Phenobarbital, frequently used as hypnotics-sedatives as well as anticonvulsants, is transferred to the fetus rapidly through the placenta. also, chronic administration of
phenobarbital
causes induction of a hepatic microsomal enzyme systems which are responsible for the biotransformation of xenobiotics. It as reported that chronic treatment of phenobarbital increased the amylase secretion from the pancreas in adult rat.
The present study, therefore, was undertaken to investigate the effect of phenobarbital treatment during pregnancy on the exocrine pancreatic function in neonatal rats.
Gravid Sprague-Dawley rats were injected intraperitoneally once daily with either 50 mg/kg phenobarbital or saline (1 ml/kg) on days 17-20 of pregnancy. Untily 30 days of age, progeny from each litter was sacrified at 3-7 day intervals by
decapitation.
The pancreas and liver were removed and homogenized in saline, and were used for the determination of enzyme activities and protein contents. The enzxyme released from the pancreatic slices was measured with or without acetylcholine (10E-6M)
stimulation.
@ES The results are summerized as follows.
@EN 1) The body weight of the phenobarbital treated rats during pregnancy was significantly higher than that of controls. On the other hand, the weight of pancreas or liver was rather decreased by phenobarbital treatment.
2) The basal releases of the amylase from the pancreatic slices of both control and phenobarbital treated groups were high at 3rd postnatal day and then decreased at 7th and 14th days.
3) The amylase releases from the pancreatic slices were significantly increased in response to acetylcholine stimulation in both groups. From 3rd days these responses were much higher in phenobarbital treated rats.
4) Compared to enzyme activities at 3rd days, amylase activity was lower at 7th while trypsin activity was highest at 7th day in control rats. In contrast to the control, treatment of phenobarbital during pregnancy caused increase in amylase
activity
in the pancreatic tissue, however the trypsin activity was decreased.
5) The protein content in the tissue of pancreas and liver was not significantly changed by phenobarbital treatment.
From these results, it is suggested that the phenobarbital treatment during pregnancy exerts significant influence on the postnatal exocrine pancreatic function, and augments the nonparallel secretion of the pancreatic enzymes.
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