Endocrinologia experimentalis最新文献

A model system to study the biochemical mechanism of follicular atresia in rats [Dhanasekaran et al. 1983] was characterized using histological and biochemical correlates. PMSG and PMSG antiserum (a/s) was used to induce the follicular growth and atresia of preovulatory follicles. Ovarian histology during these PMSG and PMSG a/s - treatment periods was recorded under a light microscope. An analysis of lysosomal enzyme cathepsin-D activity of granulosa cells (GC) from similarly treated ovaries showed that there was a reduction in cathepsin-D activity during the histologically observable follicular growth; and there was an increase in cathepsin-D activity during atresia. The increase in cathepsin-D activity also showed an inverse correlation with the general anabolic activity of the GC as demonstrated here, by a reduction in 3H-leucine incorporation activity. An analysis of other gonadotropin-responsive cells for the presence of such hormone sensitive lysosomal machinery, only corpora lutea (CL) and GC showed in the cathepsin-D activity upon treatment with 15 IU of PMSG. The results suggests the existence of a common gonadotropin regulated lysosomal machinery in cells endowed with a degenerative pathway of "programmed cell death". More importantly the results establish the validity of using lysosomal enzyme cathepsin-D as a biochemical marker, for hitherto morphologically and endocrinologically studied cellular degenerative process of follicular atresia.

The concentration of total cholesterol and triacylglycerols in plasma and their distribution in lipoproteins as well as the level of apolipoprotein-B and of endogenous testosterone were measured in 30 young sterile males before and after the treatment with methyltestosterone (Agovirin SPOFA) in a dose of 10 mg daily for 30 days. Before the treatment the level of total cholesterol in plasma and in VLDL fraction was normal, while that in LDL fraction was increased and in HDL fraction decreased. Similarly, the level of triacylglycerols in plasma was increased and correspondingly also the levels of that in all lipoprotein fractions. After the treatment no changes in total and VLDL cholesterol were found, while a significant decrease in LDL fraction and increase in HDL fraction was observed. Moreover, a significant decrease was found in a level of total plasma and VLDL triacylglycerols.

The effects of a single injection of 20 mg/kg histamine on the immunoreactive arginine-8-vasopressin (AVP) and oxytocin (OXT) levels in the rat spinal cord were studied after peripheral (intraperitoneal) administration. Histamine induced a 60% elevation in the AVP content of the spinal cord, whereas the spinal level of OXT decreased by 36%. The findings suggest that peripheral histamine differentially affects the AVP and OXT levels in the spinal cord.

Luteal cells were collected from porcine ovaries in early or midluteal phase of the cycle. The cells were cultured as monolayers for 2 days. The culture medium except that of a control one was supplemented with either 1, 10, 100 or 500 ng of FSH (NIH-FSH-S-8 OVINE) or 1, 10, 100 or 500 ng of FSH pretreated with antiserum anti-LH. Progesterone secretion by the cultures of luteal cells collected from early corpora lutea. However was stimulated by FSH in a dose-response manner when FSH was pretreated with anti-LH serum such progesterone secretion was stimulated to a lesser, although significant (P less than 0.05) extent. In contrast, FSH suppressed the secretion of estradiol by the cultures of the cells of early luteal phase, while the cells collected from the corpora lutea of midluteal phase did not respond to FSH stimulation.

The results of 11 experiments in a total of 571 rats (initial body weight of 150-250 g) are reported and some findings differing from those by others are discussed. It was repeatedly found that the animals after bilateral or even unilateral superior cervical sympathetic gangliectomy (GX) did not gain body weight during the first week after surgery. Though they started to grow later, for several weeks their body weight remained significantly less than that of sham operated controls (SH). Though such phenomenon has not yet been described, it may well explain the increase of thyroid weight (as expressed per body weight) after gangliectomy alone or combined with antithyroid drug treatment or hypophysectomy as described by others. It was suggested that such changes may depend on general metabolic changes resulting in a striking inhibition of body weight gain rather than on some specific effect of GX on the thyroid. This view was supported by evaluating the data on absolute and relative thyroid weight from 4 experiments in a total of 265 animals. The level of thyroxine (T4) and thyrotropic hormone (TSG) was repeatedly found to be significantly decreased after GX for until about 72 h and 24 h after surgery, respectively, which was in agreement with the data reported by others. However, the onset of such decrease was repeatedly found to appear at 6 or 8 h after surgery (in one experiment even at 3 h after surgery) which is also contrasting to the onset of T4 decrease at 14 h after surgery as found by others who suggested a correlation of such thyroid depression with a depletion of noradrenaline from the thyroid and may be even from median eminence. In these experiments, however, a decrease of T4 level was found several hours before the depletion of noradrenaline from the thyroid which appeared at 12 h after surgery and remained at similar level until 40 days, while no remarkable changes of that were found in SH animals (with the excretion of slight increase after 24 h). Between about 4 and 40 days after surgery no significant changes in T4 and TSH levels after GX were found as compared with SH animals is in agreement with others.4+n one experiment the increase of T4 at 2 h after TRH injection, resulting apparently from the effect of endogenous TSH, was significantly inhibited in GX animals at 8 days after surgery, while in other experiments (at 8 and 40 days after surgery) no difference in T4 level increase was found in GX animals as compared with SH ones. In general, it may be suggested that superior cervical sympathetic gangliectomy may result in some temporary and perhaps transient changes in pituitary-thyroid function in rats.

Nineteen tissue specimens obtained at surgery of male mammary gland due to persisting gynecomastia were assessed for the presence of estrogen receptors. In 13 cases the receptors were detected with the use of charcoal-dextran technique and 3H-estradiol as a ligand, the detection limit of such method being 0.2 fmol/mg of total protein. The average number of estrogen binding sites (mean +/- S. D.) was 2.49 +/- 2.47 fmol/mg total protein with the apparent association constant 2.8 X 10(9) 1 mol-1. The specificity of ligand binding to the receptor was confirmed by gradient centrifugation.

Epithelial cells of the rat's epididymal caput were cultivated according to own modification of the Kierszenbaum's method [1981]. The said modification consisted in developing primary cultures of the epithelial cells in the epididymal duct by making use of small tubular segments instead of deisolated cells of the whole epididymal duct wall. Such small segments of the tubules were procured by resorting to mechanical isolation and a 4-grade enzymatic isolation with trypsin and collagenase, whereupon the produced suspension of cells and tubules was filtered through a grid, the meshes of which being 40 X 50 microns in diameter. The cultures were made up exclusively of the tubular segments that had remained on the grid. The utilized technique of isolation gets rid of tubules from the external layer of muscle cells and fibroblasts as well as spermatozoa still prior to the inception of the culture, and provides the possibility to obtain a pure population of epithelial cells. The latter cells have the capacity to migrate from tubular fragments, and to form monolayer cultures. In the conducted cultures the epithelial cells commence secreting PAS-positive substance which was evidenced by means of histochemical and microscope-electron examinations.

The treatment of lactating mothers with 50 micrograms/100 g b.w. thyroxine s.c. daily from the 1st to 21st day of lactation resulted in earlier induction of alpha-glucosidases (pancreatic alpha-amylase, intestinal saccharase) and in earlier repression of beta-galactosidases (intestinal lactase). In contrast, the sucklings fed by thyroidectomized mothers showed a delayed induction of pancreatic alpha-amylolytic activity and intestinal saccharase, but ameliorated the repression of lactase. The treatment of another group of thyroidectomized mothers with 5 micrograms/100 g b.w. thyroxine prevented such effects mothers of thyroidectomy in sucklings.

The growth reaction of the rat adenohypophysis to estradiol was previously found to be potentiated by dopaminergic antagonists (perphenazine) and inhibited by thyroid hormones and dopaminergic agonists. In the present experiment a combination of estradiol, lisuride and thyroid hormones was tested. Sixty male Wistar rats were divided into 6 groups: 1. controls; 2. estradiol benozate (E) in aqueous microcrystal suspension 1 mg/rat twice a week; 3. Thyreoidin (SPOFA) 0.2% in the food (T); E + T; 5. E + lisuride (N-D-6-methyl-8-isoergonelyl)-N'N-diethyl carbamide hydrogen maleate, 200 micrograms/rat per day in the food (L); 5. E + T + L. After 3 weeks the adenohypophysial weights, histology (PAS Orange G, indirect immunoperoxidase technique) and electron microscopic morphometry were examined. The increase in adenohypophysial weight was inhibited by T, L and significantly more by the combination T + L. The increased incidence of prolactin cells after estradiol was inhibited by T and L and equally by the combination T + L. The effect of both inhibitory substances (T + L) was also additive on the relative size of the nucleoli of PRL cells: marked nucleolar inhibition similar to that produced by cytostatics was observed in the E + T + L group of animals.

Thyroid hormone autoantibodies (THAA] were estimated in a total of 149 patients (139 women and 10 men) with various thyroid diseases. THAA were found in a total of 22 patients (all women), i.e. 14.7%. In 8 of them both T4Ab and T3Ab were found, while T4Ab only were found in 4 patients and T3Ab only in 10 patients. The highest incidence of THAA was found in patients with diffuse lymphocytic thyroiditis (i.e. 11 cases out of a total of 64 patients) and similarly high incidence was in patients with suspected autoimmune goiter but without thin needle biopsy (i.e. 5 cases out of a total of 21 patients). If only the patients with manifested or silent hypothyroidism were selected, T4Ab were found exclusively in this group, while the incidence of T3Ab was 3 times higher as that in patients without hypothyroidism. Though the incidence of T4Ab in patients with positive antithyroglobulin and antimicrosomal antibodies was 3 times higher than in negative ones, the difference was not significant. No correlation was found between the incidence of THAA on one hand and the duration of disease, the duration of treatment and the drug used for treatment on the other. However, a significant correlation was found between the incidence of THAA and the presence of goiter (P less than 0.05).