Pregnant golden Syrian hamsters were given single or multiple intragastric doses of 9 -tetrahydrocannabinol ( 9 -THC) dissolved in olive oil. Dose levels of 125, 250, or 500 mg/kg were administered by gavage once during gestational days 7-12 and of 25, 50, or 100 mg/kg daily on days 7-10, 9-12, or 7-12 in the two experimental series. Untreated and vehicle-injected controls were used for each series. All fetuses were examined on day 15 of gestation. Larger doses of 9 -THC induced a high frequency of fetal mortality and growth retardation. Vehicle-injected controls showed up to 3% fetuses with external anomalies and several 9 -THC treated samples had higher frequencies, ranging up to 7%, but a majority of the samples did not show any statistical difference between the 9 -THC treated and corresponding control groups. However, a single dose of 500 mg/kg 9 -THC given on day 10 and four daily doses of 100 mg/kg 9 -THC on days 7-10 produced significantly higher frequencies (p < 0.05) of external anomalies, 5.36% and 4.17%, respectively, than their corresponding controls. Most of the defects were relatively minor in severity. In general, hamsters appeared to be relatively resistant to the teratogenic effects of pure 9 -THC, in contrast to the previously reported high teratogenicity by crude cannabis extract in this species. It is likely that the latter effect was not due to the action of 9 -THC but may have been the result either of interaction of various cannabinoids or of impurities in the crude preparations. In view of the data presented, it can be concluded that 9 -THC did not induce a clear-cut teratogenic response in hamsters, although a slightly higher frequency of minor defects was observed in the fetuses from 9 -THC treated dams than in the controls.

This study of sixty-five volunteers has again shown that the XYY constitution exists in some prisoners but there are no other logical deductions to be made. The subject of this study has no characteristics (apart from height) in common with the more than three hundred persons described in the literature who have the XYY chromosome.

In vitro observations of fetal lung maturation are complicated by continued epithelial cell maturation in culture. Removal of trace quantities of cortisol from the culture system has been reported elsewhere by Torday to prevent epithelial cell differentiation, but also prevent cell growth. In this report we have developed monolayer cell cultures from 18-, 19-, 20-, and 22-day-gestation fetal rat lung in a culture system stripped of steroid and thyroid hormones. These cultures demonstrate lamellar body development comparable to that seen in vivo at the gestational age at which cultures were developed; the gestation-dependent increase in precursor incorporation into saturated lecithin observed in these cultures is similar to that reported in in vivo studies, yet cell growth in culture has been preserved.

Differentiation-arrested and hormone-depleted monolayer cultures were developed from rat fetal lungs of 18-, 19-, 20-, and 22-days gestation. Incorporation of [3H]-choline into saturated phosphatidylcholine increased, whereas the rate of cell division decreased, with advancing gestational age. Both functions were modified by physiological concentrations of glucocorticoids, thyroid hormones, and insulin. Dexamethasone (0.055-5.5 nM) increased [3H]-choline incorporation into total saturated phosphatidylcholine in immature cultures only, but caused secretion in mature (day-22) cultures. Triiodothyronine (0.055-5.5 nM) increased [3H]-choline incorporation into total and secreted saturated phosphatidylcholine at all gestational ages. Insulin (5-50 microU/ml) inhibition of [3H]-choline incorporation into saturated phosphatidylcholine was evident only in mature cultures. Dexamethasone (0.55 nM), triiodothyronine (5.5 nM), and insulin (50 microU/ml) also had gestation-dependent effects on cell division.