Stimulation of the secretion of dehydroepiandrosterone by melatonin in mouse adrenals in vitro.

Adrenals of young adult male mice kept on a LD 12:12 lighting regimen for three weeks prior to study and harvested at four different circadian stages were incubated for 2 hours with 0.4 IU synthetic ACTH in 2 ml Krebs-Ringer buffer (KR), or with 50, 150, and 450 microM of melatonin in KR containing 0.4 IU ACTH. The addition of melatonin to ACTH leads to a dose dependent stimulation of production and/or secretion of DHEA into the incubation medium irrespective of the circadian stage of harvesting of the adrenals. This relationship is of interest in view of the simultaneous decrease of dehydroepiandrosterone and melatonin in the course of aging, and the effects of these compounds upon aging related changes.

Protein content and thyroid hormone release in vitro by differentiated thyroid cancer cells in the presence of estradiol, dehydroepiandrosterone, polypeptidic hormones and pesticides.

The reactivity of thyroid cancer cells treated with estradiol (E) and dehydroepiandrosterone (DHA) in the presence of other hormones (TSH, STH, insulin), myopeptide and some pesticides (aminotriazole--ATA, atrazine--ATZ, prometryne--P and ATC) proved to be active in the culture medium. Protein synthesis in sclerosing folliculo-papillary cancer cells under the treatment applied is more markedly inhibited by DHA than by E in the culture medium is compared to the control lots. Tg1 and T3 release into the culture medium under the action of T4 and TSH decreases progressively going from the control to the treated lots, in the presence of E and DHA. STH inhibits Tg1 and T3 secretion in thyroid follicular carcinoma, whether or not E or DHA are present in the culture medium.

Action of some pesticides on T4 to T3 conversion in cultured kidney and liver cells in the presence or absence of cysteine.

The influence of aminotriazole (ATA), atrazine (ATZ), prometryne (P) and ATC on T4 to T3 conversion in kidney and liver cell cultures in the presence or absence of cysteine was studied. The experiment was carried out on cell cultures (rat renal cells and human embryo cells) and organotypic cultures (rat liver cells), treated with the above mentioned pesticides in 2 doses each, in the presence of 1 microgram and 10 micrograms T4 in the culture medium. This experiment was reproduced in the same conditions supplementing the culture medium with 30 mg cysteine per 100 ml culture medium. T3 and T4 in the culture medium were measured by RIA. The proteins in the monolayer cultures were also assayed. Cysteine proved to stimulate T4 to T3 conversion at the level of human and rat kidney cells with little variation depending on the pesticide and the dose applied. Between the activities of the human and the rat cells in the presence of the same pesticide, there were clear differences. The latter are also expressed in the values of proteic synthesis taking place in the renal human embryo cells and rat renal cell cultures under the same influences.

Reactivity of cold thyroid nodule under hormonal influences: study on cell cultures.

The authors have studied the reactivity of cold thyroid nodule cells (CN) by comparison with the reactivity of normal thyroid cells (Ty), hot nodules cells (N), Graves' disease cells (G) and cells from the area proximal to cold nodules (TyC), under the influence of increased amounts of T3, TSH, STH, insulin, estradiol and KI present in the culture medium. The experiment lasted for 9-10 days. The study was carried out on monolayer cultures of cells obtained by tripsinization and on organocultures. Proteic synthesis, cytochemical and cytoenzymatic activities in the culture under the influence of the above substances were examined comparatively. After interruption of the treatment, the monolayer cultures were stained with Giemsa and examined by light microscopy. Proteic synthesis and release of Tg, T3 and T4 into the culture medium, were also examined. The organocultures were used in evaluating 125I uptake from the medium under the influence of the treatment. The results showed variation in relation to the tissue and hormone dose applied. It was especially found that TSH and estradiol cause enlargement of CN cell nuclei and an increased number of mitoses and polyploidia which might be premises for possible malignization.

The influence of thiol derivatives on synthesis of thyroid hormones in human thyroid cultured cells.

The experiments were carried out on 26 lots of thyroid cell cultures treated with sodium sulphate, lithium sulphate, lithium carbonate, cystine, cysteine, and methionine, in 2 doses each, in the presence or absence of iodine in the culture medium. The monolayer culture was used in morphologic, cytochemical and cytoenzymatic studies, and the culture medium was used for assay of thyroglobulin and thyroxin. We found that addition of aminoacids with SH or S--S groups to the culture medium causes stimulation of protein synthesis overstrain on the oxydases system at the expense of dehydrogenases. Stimulation of protein synthesis in the thyroid cell cultures under study is not accompanied by a corresponding hormonal secretory activity, the process of hormonal biosynthesis being inhibited as compared to the control culture.

Histochemical and histoenzymatic action of crinofizin in cystic mastosis and prostate adenoma studied in cell and organotypic cultures.

The work deals with the study at cell level of the action of Crinofizin on some target organs. The effect of various doses of Crinofizin (0.2, 0.1, 0.01 and 0.001 ml/culture tube) was tested on multiplication and protein synthesis in human mammary tissue cells (cystic mastosis) and human prostate adenoma in cell culture. The morphologic aspect, enzymatic activity (LDH, G-6-PDH) and mucopolysaccharides synthesis were also studied. It was found that administration of Crinofizin results in preferential development of epithelial cells at the expense of the connective-fibroblastic ones. LDH and G-6-PDH, higher in the control cultures of the epithelial type than in the fibroblastic ones, becomes uniform by decreasing in intensity in the treated lots. Acute experimentation carried out on prostate organ cultures from rats of various ages (30, 60, 90 days and 2 years) treated with 0.2ml Crinofizin/ml culture medium indicates a decrease in connective tissue intrafollicular stroma, which is well developed in the case of adenoma. LDH and G-6-PDH activity, which is higher in the case of adenoma, decreases under Crinofizin administration to the levels in the adult control. The histologic aspect of the hypertrophied prostate organ cultures from aged rats, becomes after Crinofizin administration similar to that of the adult rat organ cultures.

Influence of the "Corynebacterium parvum" vaccine and stilbostat on intratesticular development of Walker 256 carcinosarcoma in hyper- or hypothyroidized Wistar rats.

This work studies the effect of nonspecific antitumoral immunity produced by the "Corynebacterium Parvum" vaccine (C.P.) and Stilbostal on the development of Walker 256 carcinosarcoma intratesticularly grafted to hyper- or hypothyroidized Wistar rats. The thyroid hormone level was altered by administration of thyroxin, Alkiron or surgical thyroidectomy. The C.P. vaccine was given in a mixture with tumoral cells suspension and the treatment with the Stilbostat drug was started 5 days from grafting. The results show that C.P. administered in a mixture with tumoral cells suspension causes marked inhibition of the development of the primary tumor and metastasis, an effect which is not significantly influenced by the thyroid hormone level. The antitumoral effect of the Stilbostat drug is enhanced by administration of C.P. in tumoral cells suspension. The greatest effect produced by Stilbostal was noted in the hyperthyroidized lots in which the tumor was administered in a mixture with C.P.

Studies on the action of pesticides upon the endocrines using in vitro human thyroid cells culture and in vivo animal models. II. Herbicides-prometrin and terbutrin.

The effects of prometrin and terbutrin in doses of 0.001--1 mg/1.5 ml culture medium on human thyroid cell cultures were studied following up their influence on cell multipliction, proteic synthesis, enzymatic activity of thyroid cells and hormonal synthesis. The results differed in relation to the dose and the type of thyroid cell under study. The acute experiment performed on rats treated with 50 ppm/prometrin or terbutrin/kg b.w. for 15 days revealed variations in T3, T4 and LH synthesis. Both prometrin and terbutrin stimulate T3 synthesis and inhibit T4 synthesis. LH synthesis appears much increased in the hypophysis of the rats treated with terbutrin, whereas the amount of LH released into the serum is much decreased as compared to the controls.

Influence of BCG on the development of 256 Walker carcinosarcoma inoculated intratesticularly in the rat, in relation to thyroid status alerations.

The effect of nonspecific antitumoral immunity caused by BCG on intratesticular development of 256 Walker carcinosarcoma has been studied on male hyper- or hypothyroidectomized rats. Thyroid hormones level was altered by administration of T4. Alkiron or thyroidectomy. The time and route of BCG administration differed from one lot to another. Authors' results show that administration of BCG before or concomitantly with the graft stimulates tumor development, whereas administration of BCG mixed with a suspension of tumoral cells causes marked inhibition in the development of primary tumor and metastasis, an inhibition which is not influenced by the thyroid hormones level. In vitro proliferation of the tumoral cells as well as histopathologic examination of the tumors suggest the involvement of a complex process in achieving the nonspecific antitumoral immunity.

Studies on the action of pesticides upon the endocrines using in vitro human thyroid cells culture and in vivo animal models. I. Herbicides--aminotriasole (amitrol) and atrazine.

The action of aminotriasole (amitrol) and atrazine in doses of 0.001--1 mg and 0.0001--.01 mg/1.5 ml medium, respectively, upon cell cultures of human thyroid was studied in order to find out their influence on cell multiplication, proteic synthesis, enzymatic activity of thyroid cells, and hormonal synthesis. The results varied according to the dose utilized and the type of thyroid cell studied. The acute experiment carried out on rats treated 15 days with 500 ppm amitol and 50 ppm atrazine revealed variations in the T3, T4 and LH synthesis. Amitrol showed a strong inhibitory action on T3 and T4 secretion, whereas atrazine stimulated it.

The radioimmunological measurement of thyroglobulin secretion in vitro under the influence of some herbicides.

A radioimmunoassay (RIA) technique of human thyroglobulin (Tgl) was developed using 125I-Tgl and a rabbit anti-Tgl serum at the initial dilution of 1:100,000. The sensitivity of the technique was of 2.5 ng/ml. The RIA of Tgl was applied as a screening test for the in vitro secretory activity of human thyroid cells under the influence of two herbicides of the heterocyclic group (Amitrol and Atrazin). Three levels of concentration of Amitrol and Atrazin were administered to the tissue culture tubes containing in the first series of experiments perinodular tissue (Typ), and in the second one nodular tissue (TyN). The thyroid gland was surgically obtained from a patient with the diagnosis of polynodular goiter. Only the high levels (10 mg and 1.0 mg/tube, respectively) of herbicide concentration inhibited the secretion and release of Tgl, the nodular tissue being more resistant to the toxic. However, parallel studies including the dosage of the active hormones (T3, T4) are necessary in order to appreciate the value of Tgl determination as an indicator of hormogenesis in this type of experiments.

BCG influence on 256 Walker carcinosarcoma growth in rats in relation to adrenal cortex status.

BCG influence on antitumoral immunity varied in relation to the timing and the way of administration, as well as in relation to the adrenal cortex status of the animals. BCG administration several days before tumor grafting, but especially when mixed with tumoral cells determined a maximum antitumoral effect, while vaccination after the tumor had been formed enhanced its metastasization. The decrease of the endogenous corticoids secretion amplified the antitumoral effect of BCG, while exogenous cortisone diminished this effect. The study of in vitro cultivated tumoral cells as well as microscopic examination of the tumors suggest the involvement of a complex process in the achievement of the nonspecific antitumoral immunity, a process in which the adrenal cortex status plays an important role.

The serum and pituitary prolactin variations under the influence of a pesticide substance in the male rat.

Prolactin was measured in the serum and hypophysis of the male rat after five days of oral administration of malathion in suspension (200 mg/kg body), alone or associated with pimozide (a psychotropic drug). The release of prolactin observed in the group treated with malathion was lower (19.97 +/- 7.27 ng/ml) than in the groups treated with malathion and pimozide or pimozide alone (26.65 +/- 3.17 and 26.49 +/- 2.57 ng/ml, respectively) but significantly higher than in the control group (10.08 +/- 5.82 ng/ml). The administration of two dose levels of pure malathion solubilized in alcohol/water (v/v) failed to reproduce the same results. The discussions are focussed upon: 1) the mechanisms involved in the release of prolactin under the influence of malathion (vagomimetic action) and 2) the lack of cumulative effects of malathion and pimozide (presumably different levels of their influence).

Influence of stress and of endocrine imbalance on the experimental metastasis.

The influence of some stress agents applied during variable periods of time and under various modifications of the endocrine status was studied on the lymphotropic metastases of the 256 Walker carcinosarcoma, grafted intratesticulary in rats. Different reactivity of metastases, when compared to that of primary tumors was found in relation to the action of some compounds influencing the hormonal balance. Stress enhances the primary tumor development, while the metastatic growth is inhibited. However later on, sudden enhancement of the metastasis growth was observed. Adrenalectomy, as well as testosterone, thyroxine, of Stilbostat administration inhibit the metastasis, whereas cortisone, or antithyroid drug administration enhance the metastasis. The in vitro study of the tumor cell proliferation suggests some immunemorphological involvements in the development of this process.

Chromatographic evidence for vasotocin biosynthesis by cultured pineal ependymal cells from rat fetuses.

Cultured pineal ependymal cells from rat fetuses aged 17 to 19 days post-coitum release into their media a substance that has hydroosmotic, antidiuretic and rat uterine activities. Paper chromatography of concentrates from culture media demonstrates that the substance possessing all the above activities was eluted from a slow moving region (Rf 0.15-0.35) with a peak at 0.20-0.30. This region is not significantly different from the Rf of synthetic arginine vasotocin (AVT) used as standard. Neither hydroosmotic nor rat uterine activities could be detected in the chromatographic eluates from the fast moving region corresponding to the Rf of synthetic oxytocin (0.55-0.65) used as standard. The chromatographic mobility of biological activities from culture media, the ratio of the activities as well as their susceptibility to tryptic digestion, demonstrates the presence of a basic peptide indistinguishable from synthetic AVT. The total amount of AVT released into the medium during 43 days of incubation is about 40 times greater than the amount contained in non-incubated pineal glands of the same age, strongly suggesting de novo synthesis of AVT.