| 1. |
|
|
| 2. |
- Turkmen, Sahruh, et al.
(author)
-
3beta-20beta-dihydroxy-5alpha-pregnane (UC1011) antagonism of the GABA potentiation and the learning impairment induced in rats by allopregnanolone.
- 2004
-
In: European Journal of Neuroscience. - : Wiley. - 0953-816X .- 1460-9568. ; 20:6, s. 1604-1612
-
Journal article (peer-reviewed)abstract
- Allopregnanolone is a progesterone metabolite and GABA-A receptor modulator with benzodiazepine like effects, including decreased learning and memory. In vitro 3beta-hydroxypregnane steroids antagonize allopregnanolone-induced effects, but no antagonism has been shown in vivo. Our purpose was to evaluate 3beta-20beta-dihydroxy-5alpha-pregnane (UC1011) as a blocker of allopregnanolone-induced effects in vivo and in vitro in rats. We tested adult male Wistar rats in the Morris water maze 8 min after daily injections (i.v.) of allopregnanolone 2 mg/kg (n = 21); allopregnanolone : UC1011 2 : 6 (n = 7), 2 : 8 (n = 7), 2 : 20 (n = 14) mg/kg; UC1011 20 mg/kg (n = 14); or vehicle (10% 2-hydroxypropyl-beta-cyclodextrin, n = 4). Studies of chloride ion uptake into cortical and hippocampal membrane preparations were performed. The latency to find the hidden platform was still high in the allopregnanolone-injected group on day 6. Day 3-6 rats injected with allopregnanolone and UC1011 (2 : 20 mg/kg) had lower latency (P < 0.05), compared to the allopregnanolone-injected group. The group that only received UC1011 learned the location of the platform as fast as the controls. There was no significant difference in swim speed between groups. The time spent swimming close to the pool wall was in the allopregnanolone : UC1011 group (2 : 20 mg/kg) significantly decreased (P < 0.05, day 3-6), compared to the allopregnanolone-injected group. The increased chloride ion uptake induced by increasing dosage of allopregnanolone in the presence of 10 micro m GABA was significantly decreased with UC1011 (P < 0.01), in both cortical and hippocampal homogenates. In conclusion, UC1011 can via antagonism at the GABA-A receptor reduce the negative allopregnanolone effect on learning in the water maze.
|
|
| 3. |
- Turkmen, Sahruh, et al.
(author)
-
Reduction of dehydroepiandrosterone sulfate synthesis in women with polycystic ovary syndrome by human menopausal gonadotropin but not purified urinary follicle stimulating hormone : a comparative pilot study.
- 2004
-
In: Gynecological Endocrinology. - 0951-3590 .- 1473-0766. ; 19:2
-
Journal article (peer-reviewed)abstract
- We aimed to compare the effects of two different gonadotropins on steroid production in patients with polycystic ovary syndrome (PCOS). The study group comprised 20 infertile patients diagnosed with PCOS who were accepted into in vitro fertilization-embryo transfer and gamete intra-Fallopian transfer programs. Ten patients were consecutively allocated to a purified urinary follicle stimulating hormone (FSH) administration group while the other ten received human menopausal gonadotropin (hMG). All patients were pretreated with a gonadotropin releasing hormone-agonist. The patients were followed by daily vaginal ultrasonography until at least two follicles reached a diameter of 17 mm or an estradiol value of at least 100 pg/ml per follicle. To induce ovulation, human chorionic gonadotropin was given. On the 3rd day of menstruation, serum estradiol, luteinizing hormone (LH), FSH, total testosterone, androstenedione, dehydroepiandrosterone sulfate (DHEAS), insulin-like growth factor-I and insulin were measured. These same parameters were measured again on the day of follicle aspiration in both serum and follicular fluid. In both groups, the serum levels of estradiol and androstenedione were raised significantly, and on aspiration day the serum level of DHEAS was significantly raised in the FSH group but not in the hMG group. Our findings suggest that in PCOS patients exogenous hMG induces a different steroid synthesis pattern compared to pure FSH, hypothetically by reduction of the delta-5 steroid synthesis pathway in the adrenals and/or in the ovary.
|
|
