[Comparison of the transplacental effect of luminal and epileptic seizures in pregnant rabbits on the development of the fetal nervous system]. / Porównanie wplywu przeslozyskowego dzialania luminalu i napadów drgawkowych królic ciezarnych na rozwój ukladu nerwowego plodu.

The aim of the study was to compare the effect of phenobarbital given to pregnant rabbits and of epileptic seizures on the course of pregnancy, the physical state, and central nervous system development of newborns. Phenobarbital was given orally during whole pregnancy or for the last ten days in amounts 18,5 mg/kg/body weight = 0,1 DL 50. Seizures of "grand mal" type were evoked with electrostimulator every day since the tenth day of pregnancy. Phenobarbital penetrates via placenta, reaches the organs of all fetuses, and seizures provoke hypoxaemia of fetuses. Phenobarbital administered during whole pregnancy exerts an teratogenous effect. Both injurious factors applied after teratogenous period cause a retardation of general development of fetuses. After phenobarbital administration slight brain lesions are visible in the light, electron microscopical and histochemical examination. More evident was the retardation of the development of the central nervous system after both of the examined injurious factors. In the brain stem and in the cortex the neurons are less mature and the synaptic junctions in the cortex are less numerous. In our experimental models phenobarbital seems to evoke more noxious effect than seizures in mothers.

Electron microscopic findings in rat hypophysis after adrenalectomy and administration of ACTH. I. Adenohypophysis.

Ultrastructural changes in the secretory lobe of rat hypophysis following bilateral adrenalectomy and a single subcutaneous administration of 1 i.u. of ACTH were studied. Both after adrenalectomy and ACTH administration, ultrastructural changes were found to appear exclusively in one type of secretory cells. After adrenalectomy, pictures were found in these cells indicative of increased synthesis of the secretory granulations. One hour after the administration of ACTH the ACTH-secreting cells showed features of decreased secretory activity.

Electron microscopic findings in rat hypophysis after adrenalectomy and administration of ACTH. II. Neurohypophysis.

Electron-microscopic changes in the neural lobe of the rat hypophysis following adrenalectomy and a single administration of ACTH were studied. Twelve hours after adrenalectomy, a decrease in the amount of neurosecretory substances was observed, manifested by a small number of elementary granules of high electron density and, by the appearance of a great number of optically empty vesicles and masses of membrane-free material of low electron density. The increased secretion of neurosecretory substances after adrenalectomy seems to be related to the increased requirement of the organism for the ACTH-releasing factor. One hour after administration of ACTH, a picture was observed suggestive of the release of neurosecretory substances from the neural lobe fibers, which is probably connected with disturbances in the composition of blood electrolytes accompanying the excess of adrenocortical hormones.