Occurrence of oxyphil cells in suppressed parathyroid glands

Parathyroid glands from Mongolian gerbils cultured for 7 days at a high calcium concentration and examined by electron microscopy, were found to contain suppressed chief cells containing numerous mitochondria, and some oxyphil cells containing an abundance of medium-sized or large mitochondria with calcium-containing precipitates. It is suggested that parathyroid chief cells may be transformed into oxyphil cells, under certain conditions, and that the associated increase in the number and size of the mitochondria may be related to an intracellular accumulation of calcium.     

Spatial organization of proliferative processes in the parathyroid glands upon acute stimulation of parathyroid function

A quantitative analysis on homogeneity degree in distribution of proliferating parathyrocytes in the parathyroid glands under conditions of an acute stimulation of their function, produced by bilateral nephrectomy (12 rats, 50-70 h after the operation) and by hemiparathyroidectomy (12 rats, 2-3 days after the operation) have been performed. Six intact animals serve as the control. In order to reveal proliferating cells, 1 h before sacrifice 3H-thymidine (1 mc Ci/g) is injected intraperitoneally, and to some animals--colchicine (1 mg/kg) is injected 6 h before the sacrifice. By means of successive investigation of the glands serial sections along their whole area the amount of the microscope field of vision, having various content of proliferating cells are calculated; using the criterion chi 2, the correspondence of the empiric distributions obtained to the Poisson distribution are estimated. In the hyperfunctioning parathyroid glands the proliferating cells form foci of clusters and rarifaction. A similar clustering appears when a definite level of mitotic activity of the parathyrocytes is reached (1-1.2%), probably reflecting certain regional peculiarities of their functional state.     

Cryosurgery of parathyroid glands

The effectiveness of cryosurgery in destruction of parathyroid glands in rats was studied by comparison of 4 experimental groups: 1. cryosurgery utilizing 3 patterns of repetitive freezing, 2. excision, 3. sham operation, or 4. no treatment. Evaluation included clinical observation of respirations and voice, serum calcium concentration, and histologic examination of parathyroid tissue. The results indicate that the extent of destruction of parathyroid glands in rats can be controlled by specific cryosurgical techniques without thyroidectomy or risk of permanent injury to the recurrent laryngeal nerves.     

Biosynthetic activity of cultures of different species of the genus Actinomadura

The ability to synthesize antibiotics and exoproteases was studied in 13 species belonging to the Actinomadura genus. The antibiotic and proteolytic activities were found only in A. fulvescens INA-3321 and A. citrea INA-1849. Glycerol was shown to be the best carbon source for the growth and biosynthetic activity of A. fulvescens. A. citrea had a wider spectrum of carbon sources used for the growth and a higher proteolytic and antibiotic activity. A. citrea exerted the maximal biosynthetic activity and the best growth in a medium with starch and xylose. The effect of different nitrogen sources on the growth and biosynthetic activity of A. citrea was also studied.     

Effect of emotional-algesic stress on the hormonal function of thyroid and parathyroid glands

Experiments on 215 Wistar rats have revealed that the state of the endured stress is an essential factor inducing disturbance in functioning of the hypothalamus-adenohypophysis-thyroid gland system accompanied by disturbance in regulation of the thyrotropin and triiodothyronine formation under conditions of myocardium necrosis development.     

Structure of the parathyroid glands,as revealed by different methods of fixation

Summary Stereology and semi-automatic image analysis were used with the aim of comparing the structure of parathyroid glands from untreated adult Mongolian gerbils fixed by immersion with those fixed by perfusion. Subclassification of the chief cells based upon the staining affinity or electron density of the cytoplasm was readily performed only in glands fixed by immersion, and so-called atrophic cells were observed only in these glands. The atrophic cells were often surrounded by light chief cells. In glands fixed by perfusion, light chief cells were only rarely encountered. A significant difference between glands fixed by immersion and those fixed by perfusion was found only with regard to the form of cells and nuclei, those fixed by perfusion being more spherical. When comparing individual cells within glands fixed by immersion, light chief cells were more spherical and had a significantly larger nuclear and cellular size, and a lower mitochondrial volume density than the intermediate/dark chief cells. Otherwise there were no significant differences in any of the parameters investigated. These data indicate that occurrence of socalled light chief cells and atrophic cells is a result of improper fixation. The results of this study do not favour the concept of a functional cycle with a simultaneous occurrence of active and inactive cells within parathyroid glands.     

Anthropological measurements of the skeleton and parathyroid glands growth during fetal development

The article presents the investigation of histomorphological differentiation and growth of parathyroid glands in human fetus from the second to the ninth lunar month. The longer and the shorter diameter of these glands were measured. The obtained values are compared with the development and the growth intensity of the skeleton (biparietal head diameter and femoral length of a fetus from lunar months 3 to 9) and with the role of the placenta in the mentioned processes. The results of our investigation show the concordance of the skeletal growth with the development and histomorphological differentiation of these glands. The factors involved in these processes point out the complex relationship between the mother and fetus during osteogenesis, expressed on the hormonal level, in mineral metabolism and placental activity.     

Immunocytochemical localization of parathyroid hormone in rabbit parathyroid glands

Immunocytochemical localization of parathyroid hormone was examined in the rabbit parathyroid gland by means of protein A-gold technique. Protein A-gold particles were observed on the secretory granules and the large secretory granules thought to be storage granules. No protein A-gold particles were observed on cisternae of the endoplasmic reticulum and the Golgi apparatus.     

Values and limitations of the radioimmunological determination of plasma parathyroid hormone in the study of the functional activity of the parathyroid glands

Aim of the present study was to establish the limits and difficulties prevailing in RIA of PTH due to different specificity of antisera. Studies were carried out on normal volunteers and 36 patients with primary hyperparathyroidism (HPT) employing two different assay techniques a) 211/32 antiserum from Wellcome Lab. and b) Immuno Nuclear Corporation Kit. Plasma iPTH values were higher in most primary HPT patients than in normal subjects with both techniques. It is possible nevertheless to differentiate the primary HPT patients with normal plasma iPTH values from normal subjects by correlating plasma iPTH values with corresponding serum calcium values.     

Production of prostaglandins by dispersed cells and fragments from bovine parathyroid glands

We studied the production of prostaglandins by fragments and dispersed cells from bovine parathyroid glands. Fragments released 138 +/- 19 (SE), 132 +/- 21, 4.3 +/- 0.5, and 13 +/- 6.6 pg/mg/h of 6-keto-PGF1 alpha, PGF2 alpha, PGE2, and thromboxane B2, respectively (n = 7 - 26), while dispersed cells released 414 +/- 110, 22 +/- 7.3, 27 +/- 3.8, and 29 +/- 11 pg/10(6) cells/h, respectively, of the same compounds (n = 6 - 25). Indomethacin (1 microgram/ml) inhibited the release of 6-keto-PGF1 alpha by 80-90% in fragments and cells, while mellitin stimulated release of this prostaglandin, suggesting de novo synthesis of prostaglandins in these preparations. Calcium stimulated production of 6-keto-PGF1 alpha by 1.3-fold in cells and 2.6-fold in fragments and also enhanced production of PGF2 alpha by 1.9-fold in fragments. Isoproterenol, on the other hand, had no effect on production of 6-keto-PGF1 alpha in either preparation. These results demonstrate that parathyroid tissue as well as parathyroid cells per se produce a variety of prostaglandins. We have previously shown that PGE2 and PGF2 alpha modulate cAMP accumulation and PTH release in dispersed bovine parathyroid cells. The role of the endogenous production of prostaglandins by the parathyroid gland in the acute or chronic regulation of parathyroid function, however, remains to be determined.     

Regeneration of the parathyroid glands after partial resection

By means of morphometrical methods, as well as by the method of volumetric reconstruction of the organs in 33 rats during 1-30 days regeneration of parathyroid glands have been studied after a simultaneous resection of the whole left and a half of the right gland. Total calcium content in blood serum in the experimental animals decreases on the 1st-2d day and normalizes by the 3d day. Regeneration of the remained part of the gland is realized at the expense of increasing mitotic activity and hypertrophy of parathyrocytes along the whole organ from the 3d up to the 13th day. There are no signs of the glandular parenchyma growth from the wound surface. On the 3d-5th day dividing parathyrocytes predominate in the half of the gland that adjoins the wound. This promotes a predominant longitudinal growth of the gland remnant and restoration of the organ's ellipsoid form on the 20th-30th day. The main pattern of the parathyroid gland restoration after its partial resection is regenerative hypertrophy.