[Somatostatin in the hypothalamic mechanism of control over prolactin and milk secretion]. / Somatostatin v gipotalamicheskom mekhanizme kontrolia sekretsii prolaktina i moloka.

The data obtained in lactating rats suggest existence of direct functional interrelationship between somatostatin and dopamine during the lactating period, both of them taking part in the control of prolactin synthesis and milk secretion. The findings permit to characterise somatostatin as one of the accessory mechanism of the hypothalamic control of prolactin synthesis and milk secretion.

[Use of tryptophan and thyroidin for complex correction of hormonal disorders in experimental hypogalactia in rats]. / Ispol'zovanie triptofana i tireoidina v kachestve kompleksnoi korrektsii gormonal'nykh narushenii pri éksperimental'noi gipogalaktii krys.

The interlinked functioning of the hypothalamo-hypophyseo-breast and hypothalamo-hypophyseo-thyroid systems in experimental hypogalactia (electric stimulation) as well as a possibility of effective correction of neuroendocrine disorders of lactation were studied using tryptophan in combination with microdoses of thyroidin. The hypothalamic and blood concentrations of monoamines (MA) were determined by fluorometry (spectrofluorometers SFM-22, Contron, Switzerland), the blood levels of hormones were determined by a radioimmunoassay. The effect of chronic stress on the monoaminergic hypothalamic system was shown to be based on an increase in the catecholaminergic tone and suppression of serotoninergic tone. It resulted in the suppression of the synthesis and secretion of prolactin, STH, in an elevated blood level of TSH and a considerable reduction of the level of thyroid hormones. The result was weakened secretory function of the breast. Tryptophan and thyroidin administration to rats, subjected to stress, returned to normal function. The investigation brought to light the idea of pathogenesis of hypogalactia, resulting in a new approach to therapy of this pathological condition.

[The stimulation of prolactin secretion by the simultaneous inhibition of the dopaminergic and activation of the serotoninergic systems in the hypothalamus]. / Stimuliatsiia sekretsii prolaktina odnovremennoi ingibitsiei dofaminergicheskoi i aktivatsiei serotoninergicheskoi sistem gipotalamusa.

Lactotropic adenohypophyseal function and lactation intensity were studied under simultaneous blockade of dopamine receptors and stimulation of serotonin metabolism in the rat hypothalamus. Blockade of hypothalamic dopamine receptors by tricedil decreased the dopamine level, increased the serotonin content and intensified its metabolism thus increasing the prolactin secretion. Under these conditions, tryptophan application potentiated the above changes in hypothalamic catecholamine and indolamine metabolism, increased the prolactin secretion. The latter is associated with the brain serotoninergic system reactivity to suckling impulses: an important factor in the lactation reflex. Tryptophan maintains a high level of hypothalamic serotonin metabolism, maintaining an increase in the prolactin secretion level and secretory activity of the mammary glands.