[Mechanisms involved in anticonvulsive effect of pregnancy in an animal model of epilepsy].

Interrelation between pregnancy and epilepsy is one of the pressing problems of current neurology. Those mechanisms, which suppress or amplify the seizure reactions in pregnancy, have not been yet determined experimentally. Investigation of the interrelation between the epileptic fits and pregnancy in women is complicated by the bioethical considerations, as well as by the antiepileptic therapy. Therefore, in order to solve this problem, an implementing the animal models seems expedient; moreover that this problem is scarcely investigated so far. The goal of present work was investigation of impact of gestation and the postpartum period on initiation and development of convulsive reactions in the experimental animal model. Epileptic reactions were significantly suppressed during gestation (2 and 3 weeks). The data on the changes are concerned behavioral reactions and EEG seizure activity. Therefore, generalization of the seizure activity is blocked during pregnancy.

[Changes in the basal secretion of gonadotropins and the luliberin content of the hypothalamus of male rats administered catecholamines locally into the hypothalamic nuclei]. / Izmenenie bazal'noi sekretsiia gonadotropinov i soderzhaniia liuliberina v gipotalamuse u samtsov krys pri lokal'nom vvedenii katekholaminov v iadra gipotalamusa.

The effect of pharmacological agents (alpha-adrenoblockers alpha-adrenergic stimulators) and dopamine (DA) on LH secretion as well as the effect of local administration of noradrenaline (NA) and DA into the preoptic area (PA) or arcuate nuclei (ARC) on the LH-RH content in hypothalamic nuclei and blood LH and FSH concentration were investigated in experiments on male rats. An inhibitory effect of alpha-adrenoblockers on LH secretion was shown. This effect was reversed by the administration of stimulators DA or alpha-adrenoreceptors. Differences in the type of changes in LH-RH concentration and LH and FSH levels in response to NA and DA administration were established: a stimulating NA effect on the secretion of gonadotropins at the PA level was noted whereas a stimulating DA effect was more noticeable at the ARC level. Catecholamine effects were steroid-related. A conclusion was made that the regulation of tonic secretion of gonadotropins was not restricted to the mediobasal hypothalamus only: the anterior hypothalamus was also involved in control.

[Participation of catecholamines in the regulation of an induced wave of gonadotropins in ovariectomized rats]. / Uchastie katekholaminov v reguliatsii vyzvannoi volny gonadotropinov u ovariéktomirovannykh krys.

The influence of various pharmacological agents (agonists or antagonists of catecholamine action) on the LH-RH content in certain discrete areas of the hypothalamus (in the preoptic area, arcuate nuclei and median eminence) and the LH and FSH levels were studied using a model of an induced wave of gonadotropins in ovariectomized rats receiving sex steroids. The administration of alpha-adrenoreceptor antagonists blocked a rise of the level of gonadotropins in the blood. The wave was restored when mesaton (alpha-adrenoreceptor stimulator) was administered in the presence of blockers. At the same time activation of the dopaminergic system with apomorphine was ineffective. Changes in LH-RH concentration at the hypothalamus level were recorded in the preoptic area and median eminence in the gonadotropin wave blockade and in wave restoration using various pharmacological drugs which may reflect changes in the rate of metabolic processes and transport of this neuropeptide. It was concluded that the role of catecholamines was not restricted only to the activation of LH-RH release from the terminals at the level of the median eminence but was also necessary at the level of LH-RH producing cells of the hypothalamus.

[Synthetic tripeptide miniluliberin and its biological activity]. / Sinteticheskii tripeptid miniliuliberin i ego biologicheskaia aktivnost'.

The effects of the synthetic decapeptide LH-RH and tripeptide mini LH-RH on LH and FSH secretion were compared. Experiments on ovariectomized female rats receiving estradiol benzoate and progesterone showed that i. v. administration of mini LH-RH produced a stimulating effect on the release of gonadotrophins from the hypophysis. The effects of mini LH-RH were incomparable to those of LH-RH.