[The experimental use of surfagon, a synthetic analog of luliberin, in follicular ovarian cysts].

The use of a synthetic peptide analog of LH-RH agonist--[D-Ala6, des Gly10, Pro9]-LH-RH ethylamide (surfagon) at microdoses and in short courses returned to normal the ovulatory cycle in the anovulatory condition in rats and caused luteinization of follicular cysts in rats and cows with further normalization of ovarian function. It is assumed that surfagon will be effective for the treatment of anovulatory condition and ovarian follicular cysts in women.

[The effect of nizoral on hypophyseal gonadotropic function and the production of sex steroid hormones by the testes and ovaries in human subjects and experimental animals].

Experiments with mature male and female rats and female mice have shown that nizoral, a nonsteroid estrogenic drug, in a dose of 10 mg/kg stimulates estradiol production in male and female rats, suppresses basal and stimulates LH production, promotes a relative predominance of FSH in female animals, and suppresses FSH in male rats. In humans of a reproductive age, orally taking 200 mg of nizoral during 1-26 weeks, the drug stimulates FSH and LH production, suppressing estradiol production in men. The blood levels of prolactin, testosterone and progesterone are unchanged (the hypophyseal gonadotropic and the peripheral steroid hormones have been radioimmunoassayed).

[Biological activity of surfagon--a synthetic luliberin agonist].

The biological activity of surfagon (D-Ala6-desGly10-Pro9-ethylamide), a synthetic LH-RH agonist, is dozens of times higher than that of LH-RH in the test of rat hypophyseal stimulation of gonadotropin secretion in vivo and in vitro and in the ovulation induction test. A dose of surfagon required for the stimulation of LH secretion was considerably lower than that for the stimulation of FSH secretion. It may permit the use of surfagon in clinical practice for selective stimulation of secretion either of LH or total gonadotropins--LH and FSH.

[Biosynthesis of immunoreactive luteinizing hormone in the central nervous system of rats].

The authors detected the biosynthesis in vitro of the immunoreactive LH in the pineal gland and hypothalamus of rats using a specific immunosorbent to LH. The synthesis of this hormone was undetectable in the thalamus, striate body and in the cerebral cortex. Puromycin decreased the synthesis of the hormone in the pineal gland and hypothalamus by 40% and 60% respectively.

[Immunochemical method of determining the biosynthesis of hypophyseal hormones. Effect of liberins and cyclic AMP on the biosynthesis of luteinizing hormone, prolactin and growth hormone in the rat pituitary].

A simple procedure is developed, which enables to estimate sequentially the biosynthesis of luteinizing hormone (LH), prolactin (LTH) and somatotropic hormone (STH) in rat hypophysis using solid-phase immunosorbents prepared on the basis of antisera to the hormones studied, copolymerized with chlorcarbonic acid isobutyl ester. The immunosorbents exhibited high specificity and pronounced immunosorption capacity. The analysis was carried out as follows: incubation of hypophyses with 14C-lysine in vitro, chromatography of the hypophysis extracts on columns with Sephadex G-25 and immunosorption of hormones.

[Luteinizing hormone content in the hypothalamus in relation to the physiological status of rats].

Content and relative concentration (per 1 mg of protein) of luteinizing hormone (LH) varied in rat hypothalamus depending on the animal sex and age. In hamster hypothalamuses the hormone content correlated with the state of sexual cycle; maximal content of LH was found during estrus. Content of LH in hypothalamus depend also on the effect of light (rhythmic illumination, permanent light or darkness, duration of the light effect).

[Extrapituitary localization of luteinizing hormone in rats].

After hypophysectomy luteinizing hormone /LH/ did not disappear from rat blood serum within 2 months; but concentration of the hormone decreased 2-fold. Administration of luliberine into the hypophysectomized rats led to approximately 3-fold increase of the LH concentration in blood serum within 20 min. The hormones from blood serum of the hypophysectomized rats, from hypophysis and blood serum of intact rats exhibited similarity in their immunochemical and chromatographic properties.

[Relationship between the pineal body and the hypothalamo-hypophyseal system. V. Melatonin inhibition of the gonadotropic activity of the hypothalamo-hypophyseal system].

Effect of melatonin on the gonadotropic activity of the hypothalamo-hypophysial system was investigated. The following proved to occur under the action of melatonin in sexually immature female rats: reduction of the spontaneous activity of luteinizing hormone (LH), of the LH content in the hypophysis, and of the endogenous luliberin stores in the arcuate nucleus; response of the hypophysis to the exogenous luliberin was also diminished. Single administration of low doses (from 1 to 100 micrograms) of melatonin was accompanied by reduction of cAMP content in the hypophysis and the hypothalamus.