triethyllead and 2-aminoisobutyric-acid

In order to study the effect of organolead on the placental transfer of amino acids, triethyl lead chloride was administered by i.p. injections to pregnant guinea-pigs. The following day, the fetal part of the placenta was perfused in situ during i.v. infusion of alpha-aminoisobutyric acid (AIB) to the dam. It was found that triethyl lead treatment (2.5 mg/kg body wt) decreased the AIB-concentration in perfusion media compared with that of the control group. Treatment with 1 mg/kg body wt has no effect. It was also shown that the placental uptake of AIB in animals receiving 2.5 mg/kg body wt is significantly reduced compared with that of the control group. No such effect was obtained in animals receiving 1 mg/kg body wt. It is suggested that triethyl lead may inhibit placental Na+-K+-adenosinetriphosphatase, an enzyme involved with placental amino acid transport. Another possible explanation is a reduction in maternal placental blood flow.

Topics: Aminoisobutyric Acids; Animals; Body Weight; Female; Guinea Pigs; Lead; Male; Organometallic Compounds; Placenta; Pregnancy