Chronic exposure to estrogen and tamoxifen regulates synaptophysin and phosphorylated cAMP response element-binding (CREB) protein expression in CA1 of ovariectomized rat hippocampus.

We report here the in vivo effects of estrogen (E2) on modulation of synaptic plasticity and the agonistic (estrogen-like) role of selective estrogen receptor modulator (SERM), tamoxifen (TAM) in the CA1 of the rat hippocampus. Effects on synaptophysin (SYP), a presynaptic vesicular protein, and phosphorylated cyclic AMP responsive element-binding (p-CREB) protein, a signal transduction pathway molecule, were studied using the ovariectomized (OVX) experimental rat model. Bilateral ovariectomy was performed on 40 rats and these were divided into 4 groups based on the treatment they received (at 2 weeks post-ovariectomy, a subcutaneous injection daily for 4 weeks) viz.

Effect of mifepristone on steroid receptor expression and biotransformation of oestrogen and progesterone in rat uterus and deciduoma.

Background: [corrected] Mifepristone is a synthetic antiprogestin which terminates early pregnancy. Since it interferes with the progesterone maintained decidua, we compared the effect of mifepristone on oestrogen and progesterone receptors, and on the biotransformation of these hormones in normal and deciduous uterus.

Methods: Ovariectomized rats were treated with an oestrogen-progesterone hormone regimen and deciduoma was induced by trauma in one horn of the rat uterus while the other served as a control under an identical hormonal milieu.

Estrogen receptor alpha and beta immunoreactive neurons in normal adult and aged female rat hippocampus: a qualitative and quantitative study.

We have studied the distribution pattern and levels of expression of two estrogen receptor (ER) subtypes, ERalpha and ERbeta, in the normal adult (n = 10) and the aged (n = 10) female rat hippocampus with the objective to establish baseline data and the changes that occur during aging. Techniques including immunohistochemical localization, co-localization with double immunofluorescence and confocal microscopy, image analysis including neuronal counts/mm(2) area and measurements of optical density (OD) of immunoreactivity in immunoreactive neurons and Western blot analysis have been used. The results revealed ERalpha and ERbeta positive neurons in all subfields of the hippocampus with maximum presence in the stratum pyramidale of CA3.

Do the progesterone receptors have a role to play in gallbladder cancer?

Background: Gallstone disease as well as gallbladder cancer are more common in women and female sex hormones may be involved in their etiology.

Aim And Methods: To determine whether female sex hormones have a role in the pathogenesis, of gallbladder carcinoma and in its prognosis, we estimated, by enzyme immunoassay, the estrogen and progesterone receptors (ER and PgR) in the gallbladders of 21 patients with gallbladder cancer, 19 patients with cholelithiasis, and 6 patients who underwent incidental removal of essentially normal gallbladder as a component of wider resection.

Results: ER were present in the gallbladder mucosa in all the three groups in proportions which were not significantly different (9/21 in carcinoma, 4/19 in gallstones, and 1/6 normal), whereas the expression of PgR was greater in carcinomas (13/18), less in cholelithiasis (4/12), and absent in normal gallbladders.

Phyto-oestrogens and prostatic growth.

The incidence of and mortality from prostatic cancer in the West is higher than that in Asian countries. Migrants from Asia to western countries, who maintain their traditional diet, do not have an increased risk of prostatic cancer. This has been attributed in part to 'phyto-oestrogens' in vegetarian Asian diets.

Value of serum CEA and AFP in the diagnosis and prognosis of carcinoma gallbladder.

Background/objective: The poor prognosis of carcinoma of the gallbladder (CAGB) is attributable to delayed presentation in the absence of specific clinical findings in the early stages. To ascertain whether the commonly available serum tumour markers (carcino-embryonic antigen-CEA and alpha foeto protein-AFP) could be used for distinguishing CAGB from other biliary disorders and in assessing the prognosis of patients with CAGB, serum levels of these markers in patients with CAGB and those with cholelithiasis were studied.

Methods: Estimation of serum CEA in 28 patients with CAGB and 30 patients with cholelithiasis and AFP in some of these cases was done by enzyme immunoassay.

Effect of hormones and antihormones on phospholipase A2 activity in human endometrial stromal cells.

Phospholipase A2 activity was studied in isolated human endometrial predecidual cells, and in human endometrium collected from day 19-23 of the menstrual cycle, by performing a radiochemical assay. Phospholipase A2 activity on day 20 was significantly higher than other days (P < 0.001), and the activity was found to gradually decrease after day 20 of the menstrual cycle.

Effect of antiprogestin RU 486 on the proliferation and metabolic activity of stromal cells separated from human endometrium.

The effects of RU 486 on the proliferation and metabolic activity of human endometrial stromal cells in culture were studied. RU 486 at 10(-7) M/well significantly stimulated (P < 0.001) the growth as well as metabolic activity in the culture system.

Tamoxifen increases the proliferation of human endometrial stromal cells in in vitro. A model for evaluation of endometrial hyperplasia.

Tamoxifen given for breast cancer therapy, has a complex and an unclear action on the endometrium. A large number of literatures has attributed the proliferous changes in the endometrium caused by tamoxifen (Tam). No report has appeared on the endometrial cellular changes induced by Tam.

Effect of tamoxifen, estradiol 17 beta on coenzymes NAD, NADPH and the metabolism of estradiol and estrone in rabbit uterus in vivo.

Biotransformation of estradiol (E2) and estrone (E1) and the concentrations of NAD, NADPH and 17 beta-estradiol dehydrogenase (E2DH) were measured in the uterus of rabbits treated with tamoxifen (Tam) in two doses; 100 micrograms/day, (Tam 100) and 500 micrograms/day, (Tam 500), E2 (10 micrograms/day) and combination of E2 + Tam 500 for 4 days. The concentration of NAD in Tam 500 treated group was significantly higher than E2, low dose Tam and E2 + Tam 500 treated groups (P < 0.01).

Short term treatment of tamoxifen and estradiol on estradiol and progesterone receptors in rabbit uterus.

Effects of tamoxifen (Tam) on cytosolic estradiol (E2) receptors (ERc), progesterone (P4) receptors (PRc), nuclear estradiol (ERn) and progesterone receptors (PRn) were studied in adult normal rabbit uterine tissue. The ratio of cytosol: nuclear estradiol receptors (ER) was greater in rabbits treated with Tam than E2 or control uterine tissues. Rabbit uterine progesterone receptors (PR) in E2 treated animal were greater than Tam-treated animals.

Progestin and antiprogestin interactions with progesterone receptors in human myomas.

Progesterone receptors (PRs) in human fibromyomata (myomas) and normal myometrium were characterized by gel filtration, sucrose gradient sedimentation analysis, isoelectrofocusing and ligand specificity. The PR population in myoma tissues, 1242 +/- 505 fmol/mg protein, was 3-fold higher than normal myometrial tissues under similar hormonal milieu. The increased PR concentration in myomas appears to be of potential importance in physiopathology of fibromyoma.

Functional estrogen receptors as biochemical marker for the detection of hormone-dependent breast cancer.

The translocatable receptors categorized as functional receptors were quantitated in a cross-incubation study of breast cancer nuclei with receptor-rich uterine cytosol. Data demonstrated that tumors that contained cytosolic estrogen receptor (ER) but had translocation defect might not be hormone dependent, whereas tumors with low ER but intact nuclear translocation step will respond to antiestrogen therapy. Cytosolic ER was estimated in 114 primary breast cancer tissues and ten metastatic axillary lymph nodes; 58% of postmenopausal and 54% of premenopausal breast cancer tissues were ER+ with a cutoff value of 10 fmoles and 3 fmoles/mg protein, respectively.

Effect of progestins, estradiol, and coenzymes NAD and NADPH on the interconversion of estradiol and estrone in rabbit uterus in vitro.

The biotransformation of estradiol (E2) and estrone (E1) in the uterus of rabbits treated with norgestrel (NG), norethindrone (NET), norethindrone acetate (NETA), progesterone (P4), and E2 either by subcutaneous injection in oil or by intrauterine steroid-releasing silastic implants was carried out under an in vitro short-term incubation system. The studies have shown that E2 stimulates 17 beta-hydroxysteroid dehydrogenase (17 beta-OHSD) much more than P4 as compared to untreated controls. The kinetic studies on E2 metabolism in the presence of added coenzyme NAD showed an initial rapid estrone formation and a gradual reconversion of E1 to E2.

Interaction of antiprogestins with progesterone receptors in rat uterus.

Cytosolic and nuclear progesterone receptors (PRc and PRn) under antiprogestin treatment were measured in rat deciduoma and compared with values for contralateral (nondeciduomatous) rat uterine tissue. Uterine PRc and PRn of the progesterone treated group were 101 +/- 8.7 and 4770 +/- 590 fmol/mg DNA respectively.