Prenatal programming of hepatic monoamine oxidase by 5,5-diphenylhydantoin.
ABSTRACT During ontogeny, rat liver monoamine oxidase gradually increased in activity in both sexes until the pubertal period when female activity rose 1.5- to 2.0-fold higher than male activity. Oral administration of 5,5-diphenylhydantoin (10 mg/kg body wt) to pregnant rats on days 7,9, 12, 14and 16 of gestation had no effect on the monoamine oxidase activity of immature male or female offspring. The enzyme activity in adult male offspring, from females prenatally treated with diphenylhydantoin, was elevated to a level similar to that of adult females. Subcutaneous injection of diphenylhydantoin (10 mg/kg body wt) for 5 days prior to death failed to induce changes in monoamine oxidase activity in either pre- or postpubertal males or females. Thus, prenatal administration of diphenylhydantoin can program changes in adult male monoamine oxidase activity. The serum levels of testosterone in the male offspring of prenatally treated females, on days 5 and 63 postpartum, were the same as those of their respective controls, demonstrating that the changes caused by diphenylhydantoin are not due to diminished levels of testosterone.
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ABSTRACT: The human foetus is more capable of metabolizing xenobiotics than foetuses of common laboratory animal species. However, xenobiotic metabolism in animal foetuses is inducible by the exposure of the mother to various inducers during late pregnancy. Xenobiotic metabolism in neonates is more easily inducible than in foetal animals. With respect to the human foetus at mid-pregnancy, the hepatic enzyme systems do not seem to be readily inducible by exoaenous inducers, whereas the placental monooxygenase system is almost totaly dependent on maternal cigarette smoking. In the human newborn, indirect evidence points to the possibility of induction by potential inducers. The ontogenetic development of xenobiotic metabolism is probably regulated by endogenous hormones. It is possible that environmental factors may effect these normal regulatory and "imprinting" phenomena and thus lead to permanent disturbances in xenobiotic metabolism.European Journal of Clinical Pharmacology 08/1980; 18(1):17-24. · 2.74 Impact Factor
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ABSTRACT: A method for minimizing the instantaneous torque ripple in switched reluctance (SR) machines is investigated and implemented. The method is based on estimating the instantaneous SR motor torque from the flux linkage versus current and rotor position characteristic curves via a bi-cubic spline interpolation. These coefficients are computed offline, stored in a given memory location of the control processor, and used by two routines that are capable of estimating the rotor position and electromagnetic torque from the phase voltages and currents. The estimated output torque is then compared to a constant reference value, and the result of this comparison drives a current regulator that generates the proper motor phase currents. The ripple minimization scheme is simple and does not require a very fast processor. Its feasibility is confirmed via simulation and some preliminary experimental resultsPower Electronics Specialists Conference, 1992. PESC '92 Record., 23rd Annual IEEE; 01/1992
- Cancer Research 07/1983; 43(6):2576-83. · 8.65 Impact Factor