IODINATED PARTICLES IN THE RAT THYROID

1975 ◽  
Vol 79 (3) ◽  
pp. 459-473 ◽  
Author(s):  
J. Dang ◽  
R. Miquelis ◽  
P. Bastiani ◽  
C. Simon
Keyword(s):  
Acid Phosphatase ◽  
Thyroid Gland ◽  
Phosphatase Activity ◽  
Acid Phosphatase Activity ◽  
High Turnover ◽  
Secondary Lysosomes ◽  
Rat Thyroid ◽  
Tsh Stimulation

ABSTRACT In a previous study (Simon et al. 1971) a procedure for the preparation and separation of iodinated particles was described in the rat. The present paper deals with further investigations on the nature of these particles. Acid phosphatase and iodine are conjointly sedimentable and display a latency that is unmasked on dilution in a hypo-osmotic medium and under acidification to pH 5.0. These properties together with the sensitivity to Triton X-100 are best accounted for by assuming that iodinated particles of the thyroid gland are lysosomes. Part of the particulate iodine is soluble in n-butanol (BEI fraction). The existence of this BEI fraction demonstrates that hydrolysis of thyroglobulin occurs within the particles which thus exhibit an acid protease activity. Both the sedimentable iodine pool and acid phosphatase are increased under TSH stimulation and decreased after thyroxine treatment. In addition, the general activity of the iodinated particles is dependent on the daily iodine intake as shown by the variation of their iodine pool, acid phosphatase activity and BEI fraction with the iodine diet. It is concluded that iodinated particles of the thyroid gland are secondary lysosomes which participate in iodine secretion under TSH control. By in vitro treatment with destabilizing media or after in vivo treatment with thyroxine, iodinated particles exhibit a parallel loss of iodine and acid phosphatase. After a short-term TSH treatment in vivo, their iodine pool is more increased than their acid phosphatase activity. It is concluded that, at least in the normal rat thyroid, iodinated particles are essentially secondary lysosomes; true colloid droplets actually accumulate only after sufficient TSH stimulation. After ultracentrifugation, 3 main subpopulations are separated for which iodine and acid phosphatase patterns are superimposed. In addition, they all exhibit properties characteristic of secondary lysosomes. Finally, the presence of a fourth sedimentable iodinated fraction with a high turnover rate is postulated.

scholarly journals Chick osteoblasts contain fluoride-sensitive acid phosphatase activity.

1988 ◽  
Vol 36 (9) ◽  
pp. 1175-1180 ◽  
Author(s):  
M W Lundy ◽  
K H Lau ◽  
H C Blair ◽  
D J Baylink
Keyword(s):  
Acid Phosphatase ◽  
Phosphatase Activity ◽  
Acid Phosphatase Activity ◽  
Bone Matrix ◽  
Competitive Inhibitor ◽  
Cellular Origin ◽  
Embryonic Chicken ◽  
Low Concentrations

We used histological and biochemical methods to determine the cellular origin of bone matrix fluoride-sensitive acid phosphatase in chicken bone. Embryonic chicken calvariae were embedded in plastic and sections stained for acid phosphatase at various concentrations of substrate and fluoride. Acid phosphatase activity was observed in osteoblasts and osteoclasts but not in fibroblasts. Striking inhibition of osteoblastic acid phosphatase occurred at 100 microM fluoride, a concentration that had no apparent effect on osteoclastic acid phosphatase. Inhibition of osteoblastic and osteoclastic acid phosphatase by fluoride was also examined using extracts of embryonic chicken calvarial cells, mouse osteoblasts (MC3T3-El cell line), and purified chick osteoclasts, respectively. Fluoride is a partial competitive inhibitor of both chicken and mouse osteoblastic acid phosphatases, with apparent inhibition constants of 10-100 microM. These concentrations of fluoride correspond to those that increase bone formation in vitro and in vivo. In contrast, the apparent inhibition constant for fluoride of osteoclastic acid phosphatase was much higher (i.e., 0.5 mM). In summary, this study demonstrates that chicken osteoblasts contain an acid phosphatase that is sensitive to inhibition by low concentrations (i.e., microM) of fluoride.

scholarly journals The Antiosteoporosis Effects of Zhuanggu Guanjie Pill In Vitro and In Vivo

2018 ◽  
Vol 2018 ◽  
pp. 1-11 ◽  
Author(s):  
Li-juan Chai ◽  
Yue Zhang ◽  
Pan-yang Zhang ◽  
Ya-nan Bi ◽  
Xiao-mei Yuan ◽  
...  
Keyword(s):  
Acid Phosphatase ◽  
Bone Resorption ◽  
Phosphatase Activity ◽  
Bone Strength ◽  
Acid Phosphatase Activity ◽  
Ovariectomized Rats ◽  
Tartrate Resistant Acid Phosphatase ◽  
Trabecular Thickness

We investigated the beneficial effects and underlying mechanisms of Zhuanggu Guanjie (ZGGJ) pill in osteoporosis in vitro and in vivo. Bone marrow macrophages from 4–6-week-old mice were cultured in the presence of macrophage colony-stimulating factor (15 ng/mL) and receptor activator of nuclear factor-κB ligand (30 ng/mL). Osteoclast differentiation was determined by quantification of tartrate-resistant acid phosphatase activity. Gelatin zymography was used to detect the activity of matrix metalloproteinases in osteoclasts. Ovariectomized rats were administered orally with estradiol valerate or ZGGJ for 8 weeks. Blood was collected to measure serum indices. Tibiae were harvested to carry out bone microcomputed tomography scanning, histomorphological analysis, and bone strength determination. ZGGJ inhibited tartrate-resistant acid phosphatase activity, matrix metalloproteinase 9 expression, and bone resorption in vitro. At doses of 0.55, 1.1, and 2.2 g/kg, ZGGJ exerted significant osteoprotective effects including inhibition of bone turnover markers and improved tibia bone strength in ovariectomized rats. Microcomputed tomographic analysis showed that ZGGJ improved the trabecular architecture with increased connectivity density and trabecular thickness and decreased trabecular spacing. These results revealed that ZGGJ prevents bone loss induced by ovariectomy in rats and that inhibition of bone resorption is involved in the bone-protective effects of ZGGJ.

scholarly journals Ultrastructure of blebbing and phagocytosis of blebs by hyperplastic thyroid epithelial cells in vivo.

1977 ◽  
Vol 72 (3) ◽  
pp. 584-594 ◽  
Author(s):  
J D Zeligs ◽  
S H Wollman
Keyword(s):  
Thyroid Gland ◽  
Epithelial Cells ◽  
Cultured Cells ◽  
Ultrastructural Organization ◽  
Contractile Ring ◽  
Phagocytic Process ◽  
Different Types ◽  
Rat Thyroid

In addition to pseudopods, somewhat pleomorphic blebs were consistently found protruding from the apical surfaces of hyperplastic rat thyroid epithelial cells into the follicular lumens in vivo. Many blebs were knobby, roughly hemispherical protrusions, with a diameter of 2-3 mum. Such blebs had a densely packed microfilamentous core and contained numerous apparent ribosomes. They were morphologically similar to blebs that have been observed in a variety of cultured cells. Other blebs were larger, more elongate, and less knobby, but had a similar ultrastructural organization. Blebs of all sizes appeared to be phagocytosed on some occasions by nearby epithelial cells. The phagocytic process involved partial engulfment of the bleb by a typical epithelial pseudopod, followed by an apparent pinching-off process, presumably resulting in the separation of the bleb from its cells or origin. The pinching-off process was associated with a band of approx. 6-nm diameter microfilaments that developed within the pseudopod cytoplasm surrounding the base of the bleb and is postulated to function as a contractile ring. The finding of blebbing is an intact tissue in vivo indicates that this phenomenon is not restricted to cultured cells, and thus tends to extend the significance of in vitro observations of the process. In relation to their occurrence in the hyperplastic thyroid gland in vivo, possible interconversions are considered between different types of blebs, and between blebs and pseudopods.

Preservation of acid phosphatase activity in medico-legal specimens.

1978 ◽  
Vol 24 (3) ◽  
pp. 486-488 ◽  
Author(s):  
R K Lantz ◽  
R B Eisenberg
Keyword(s):  
Acid Phosphatase ◽  
Ambient Temperature ◽  
Phosphatase Activity ◽  
Sodium Azide ◽  
Acid Phosphatase Activity ◽  
Normal Values ◽  
Bovine Albumin ◽  
Support Medium ◽  
In Vivo Degradation

Abstract Vaginal acid phosphatase has been preserved with a protective broth containing, per liter, 50 of bovine albumin, 0.2 g of sodium azide, 10 mmol of phosphate (pH 7.4), and 9.0 g of NaCl. Samples may be maintained at ambient temperature for one month without loss of activity. Several other commonly used preservative methods are compared and are shown to be inadequate. With a constant 2.5 ml volume of the support medium, and use of a sodium thymolphthalein monophosphate method (Worthington Diagnostics), vaginal acid phosphatase activity in non-coital women is less than 10 U/liter of broth, and in recently post-coital women is more than 50 U/liter (242 +/- 104 U/liter). In vivo degradation of vaginal activity follows a nearly logarithmic course until four days after intercourse, when it reaches nearly normal values.

Evidence for a thyroid-inhibiting factor of adenohypophysial origin

1964 ◽  
Vol 206 (5) ◽  
pp. 1145-1150 ◽  
Author(s):  
Israel Posner ◽  
Enrique Pimentel
Keyword(s):  
Anterior Pituitary ◽  
Inhibitory Effect ◽  
In Vivo Studies ◽  
Pituitary Extract ◽  
Inhibiting Factor ◽  
Rat Thyroid ◽  
Tsh Stimulation ◽  
Stimulation Of

Thyroids of normal or thyroxine ( T4)-pretreated rats were incubated in vitro in a serum medium containing I131. It was found that the addition of either a whole rat adenohypophysis, a crude rat anterior pituitary extract, or of commercial bovine thyrotrophin (TSH) to the medium caused a slight stimulation of I131 release and no apparent stimulation but rather an immediate and considerable inhibition of thyroid-I131 uptake. Preincubation of rat thyroid with crude anterior pituitary extract resulted in a prolonged inhibitory effect on the thyroid-I131 uptake. In vivo studies showed that shortly after TSH administration a similar inhibition of uptake occurred in normal rats, although allowing 24 hr for TSH stimulation brought about no change in iodine uptake in thyroids of normal and a marked increase in uptake by thyroids of T4-pretreated rats. The inhibition of thyroid-I131 uptake was assumed to have been caused either by TSH itself, or by a thyroid-inhibiting factor of adenohypophysial origin present in commercial TSH preparations as a contaminant.

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