共查询到20条相似文献,搜索用时 15 毫秒
1.
A D Lutsik A M Iashchenko E S Detiuk 《Biulleten' eksperimental'no? biologii i meditsiny》1987,103(4):492-495
Using lectin-peroxidase technique, the influence of hypo- and hyperthyroidism on histotopography of glycoconjugates has been investigated in rat submandibular gland. The following lectins were used: peanut agglutinin (PNA), wheat germ agglutinin (WGA), Laburnum anagyroides lectin (LAL) and concanavalin A (con A). It has been demonstrated that hyperthyroidism is accompanied by the loss of con A, WGA and LAL receptor sites. Hypothyrodism enhanced con A binding to granular duct cells with a parallel reduction in WGA and LAL binding to these or other duct cells. Hypothyroidism as well as hyperthyroidism markedly enhanced PNA binding to duct epitheliocytes with redistribution of these lectin binding sites from the luminal surface of salivary ducts into the cytoplasm of duct cells. Possible interpretations of the observed phenomena are discussed. 相似文献
2.
We have developed a post-embedding immunogold technique for electron microscopic localization and quantitation of thyroglobulin (TG), thyroxine (T4), and triiodothyronine (T3) in rat thyroid. Labeling for TG was located on rough endoplasmic reticulum, Golgi apparatus, exocytotic vesicles, luminal colloid, colloid droplets, and lysosomes, whereas labeling for thyroid hormones was located on luminal colloid, colloid droplets, and lysosomes. We tested different procedures of fixation, dehydration, embedding, polymerization, and immunoincubation to optimize ultrastructural preservation and immunolabeling. Fixation with glutaraldehyde and osmium was possible with retained antigenicity. Dehydration temperature and the choice of embedding resin were the two crucial factors for good immunolabeling. Low-temperature dehydration greatly improved immunolabeling and could be combined with embedding in the methacrylate LR White or the epoxide Agar 100 (equivalent of Epon 812) polymerized at 40-60 degrees C, as the temperature during subsequent embedding and polymerization was of little importance for the immunoreactivity. Labeling on LR White sections was always higher than on Agar 100 sections. Various etching procedures were tested without improved specific labeling. Etching with hydrochloric acid gave nonspecific labeling of certain cell compartments. 相似文献
3.
4.
5.
S. V. Lupachik L. I. Nadol’nik Z. V. Netsetskaya V. V. Vinogradov 《Biochemistry (Moscow) Supplemental Series B: Biomedical Chemistry》2007,1(1):53-57
Concentration of thyroid hormones in the serum of the rats after 14-day injections of potassium iodide (1, 3, 10, 100, and 500 physiological daily doses) did not differ from the control values. Excessive administration of potassium iodide increased the total iodide content in the rat thyroid tissue by 60–121% (35–108% and 94–128% for the protein-bound and free iodide, respectively), indicating the activation of the uptake and organification of iodide. The long-term injection of both low and high doses of potassium iodide increased the activity of catalase by 8–18% and SOD by 33–50% and enhanced the level of toxic LPO products reacting with thiobarbituric acid by 15–38%. It is suggested that reactive oxygen species and the excessive iodination of proteins (particularly thyroglobulin) induced by the long-term administration of high doses of potassium iodide can play an important role in the development of thyroid dysfunctions and autoimmune diseases. 相似文献
6.
7.
8.
9.
G V Ditiateva I A Krasnovskaia V I Skopicheva 《Biulleten' eksperimental'no? biologii i meditsiny》1990,110(10):423-425
The response of the rat thyroid gland to arginine-vasopressin in vitro was studied to clear a possibility of a direct regulation of this gland by hypothalamic nonapeptide neurohormones. The function of the thyroid gland was estimated by thyrocyte height and quantity of the autoradiographs on a thyrocyte. AVP makes more active hormone synthesis in thyrocytes after 30 min of incubation and it stimulates both synthesis and secretion of the thyroid hormones in 2 hours of incubation. The higher concentrations of AVP activate the thyroid hormone synthesis but not the secretion. 相似文献
10.
L V Gerbil'ski? 《Biulleten' eksperimental'no? biologii i meditsiny》1984,97(4):501-504
Four hours after administering angiotensin to rats accumulation of radioactive iodine by the thyroid glands is inhibited. Angiotensin produces the contraction of thyroid arterioles. The cytoplasm of endotheliocytes of the perifollicular exchange microvessels becomes dense and luminar surfaces very involuted. Administration of angiotensin also leads to the changes in the ultrastructure of thyrocytes. The cisternae of the granular endoplasmic network get enlarged, the number of membrane-associated ribosome and mitochondria diminishes, that of lysosomes increases. 相似文献
11.
12.
13.
Hypercalcemia was induced in rats by the administration of A.T.10. We then determined the levels of total and ionized calcium and calcitonin in the serum, as well as performed ultrastructural observations and histochemical investigations of the calcitonin and neuron-specific enolase immunoreactivities in the stimulated parafollicular cells. The main aim of the study was to apply histochemical procedures to determine the immunoreactions of calcitonin gene-related peptide (CGRP), somatostatin and secretory protein-I in stimulated parafollicular cells. Immunoreactions of CGRP and calcitonin decreased strikingly in A.T.10-treated animals, whereas no visible changes were noted in somatostatin immunoreactivity. In the case of secretory protein-I, an insignificant increase of its immunoreactivity was observed in the treated animals. The cytophysiological significance of these results is discussed. 相似文献
14.
Summary Hypercalcemia was induced in rats by the administration of A.T.10. We then determined the levels of total and ionized calcium and calcitonin in the serum, as well as performed ultrastructural observations and histochemical investigations of the calcitonin and neuron-specific enolase immunoreactivities in the stimulated parafollicular cells. The main aim of the study was to apply histochemical procedures to determine the immunoreactions of calcitonin gene-related peptide (CGRP), somatostatin and secretory protein-I in stimulated parafollicular cells. Immunoreactions of CGRP and calcitonin decreased strikingly in A.T.10-treated animals, whereas no visible changes were noted in somatostatin immunoreactivity. In the case of secretory protein-I, an insignificant increase of its immunoreactivity was observed in the treated animals. The cytophysiological significance of these results is discussed.Dedicated to Professor Dr. T.H. Schiebler on the occasion of his 65th birthday 相似文献
15.
16.
17.
18.
《Saudi Journal of Biological Sciences》2017,24(6):1117-1125
The aim of the present study was to investigate histological alterations of rat thyroid gland after short-term treatment with supraphysiological doses of thyroid hormones. Rats from experimental groups were treated with triiodothyronine (T3) or thyroxine (T4) during five days. In both treated groups, thyrocyte height was reduced and follicular lumens were distended. Progressive involutive changes of the thyroid parenchyma were apparent, including follicular remodeling (fusion) and death of thyrocytes. Morphological changes confirmed by quantitative analysis were more pronounced in the T4-treated group. Our results demonstrate that thyrotoxicosis, whether induced by T3 or T4, leads to different grades of thyroid tissue injury, including some irreversible damages. These changes might be explained at least in part by lack of trophic and cytoprotective effects of the thyroid stimulating hormone. Since the period required for morphophysiological recovery may be unpredictable, findings presented here should be taken into consideration in cases where the thyroid hormones are used as a treatment for thyroid and non-thyroid related conditions. 相似文献
19.
20.
I A Krasnovskaia T V She?bak A L Polenov 《Biulleten' eksperimental'no? biologii i meditsiny》1987,104(12):666-669
Male Wistar rats were hypophysectomized 7 days (group 1) and 4-7 weeks (group II) before exposure to hypothermia (4 degrees C for 1 1/2 h). The hypophysectomized rats from group I were devoid of both the posterior lobe and the adenohypophysis, while the rats from group II had the posterior hypophysis but not the adenohypophysis regenerated. A decreased arginine-vasopressin (AVP) blood level in group I (32%) and a very high level of AVP in group II (311%, P less than 0.05) was determined by RIA. The exposure to hypothermia did not influence the AVP plasma level. The thyroid hypofunction was revealed morphometrically in both hypophysectomized groups. Nevertheless, cooling stimulated the thyroid glands in rats of both experimental groups, like it was in the control. Thus, there is no evidence that thyroid gland reaction to hypothermia is affected by AVP. Cooling caused an increase of corticosteroid blood and adrenal cortex content in nonoperated control rats as well as in group II, but not in group I of experimental animals. Hence, it may be assumed that when the adenohypophysis is ablated, a high AVP blood level is necessary to realize the adrenal cortex response to hypothermia. 相似文献