Phytochelatin synthase, a dipeptidyltransferase that undergoes multisite acylation with gamma-glutamylcysteine during catalysis: stoichiometric and site-directed mutagenic analysis of arabidopsis thaliana PCS1-catalyzed phytochelatin synthesis.

Phytochelatin (PC) synthase has been assumed to be a gamma-glutamylcysteine dipeptidyl transpeptidase (EC 2.3.2.

New evidences for participation of biogenic monoamines in androgen-dependent sexual differentiation of hypothalamic control of gonadotropin secretion in rats.

Corpora lutea have been found in the ovarian tissue transplanted into the anterior ocular chamber of castrated two-month-old male rats receiving on 3rd through 7th post-natal days alpha-methyl-p-tyrosine or p-chlorophenylalanine. Administration of these agents in combination with testosterone propionate to newborn female rats prevented essentially development of the anovulatory syndrome and maintained a normal picture of vaginal smears, ovarian and uterine structure as well as cyclic changes of adenohypophyseal and blood plasma lutropin contents and normal levels of estradiol and progesterone in the blood plasma except of progesterone level in animals receiving alpha-methyl-p-tyrosine. The preventive effect of the adrenoblocking agents droperidol and propranolol was weak and inconstant.

[Antiandrogenic effects of 4-nitro-3-trifluoromethylisobutyrylanilide (niftolide) in prepubertal male rats during stimulation with exogenous gonadotropins].

Nonsteroid antiandrogen 4-nitro-3-trifluoromethylisobutyranilide (10 mg/kg per os from the 26th to the 37th day after birth) decreased the weight of the accessory sex organs, and levator ani muscle. DNA, RNA, and protein content in the ventral prostate and the seminal vesicles, the thickness of the secretory cell epithelium of the ventral prostate under conditions of stimulation of prepubertal male rat gonads with human gonadotropin (100 Units/kg subcutaneously from the 21st to the 37th day after birth). The mentioned effects were observed against the background of hyperplasia and hypertrophy of Leidig's cells and increase of the activity of steroid-delta5-3beta-ol-dehydrogenase of the testes activity.

[Preventive action of catecholamine and serotonin synthesis inhibitors and of adrenergic blockaders on the occurrence of the anovular syndrome in neonatally androgenized rats. I].

Administration of catecholamine synthesis inhibitors (alpha-methl-p-tyrosine) or serotonin (parachlorphenylalanine) simultaneously with testosterone propionate prevented the anovular sterility in the majority of the neonatally androgenized rats. Preventive action of adrenoblockers (droperidol and propranolol) on the effects of early androgenization were weak. The data obtained pointed to the participation of catecholamines and serotonin in the realization of the masculinizing action of androgen on the neuroendocrine centres of the gonadotropin hormones secretion control.

[Experimental anti-androgenic activity of 4-nitro-3-trifluoromethylisobutyranilide (niftholide) in rats and guinea pigs].

In experiments on rats and guinea pigs is shown the capability of the synthetized nesteroid antiandrogen--4-nitro-3-trifluormethylisobutyranilide (niftholide) to block the stimulating effect of exogenous and endogenous testosteon on the prostate, seminal vesicles and levator ani muscle. The results of histological and morphometric investigations bear proof to inhibition of the hypertrophic reaction of theprostatic epithelium in response to introduction of the androgen. It is inferred that antiandrogenic effect of niftholide with respect to testerone manifests itself on the level of the target-organs.