The effect of strontium, cobalt and fluoride on rat incisor enamel formation

1975 ◽  
Vol 183 (2) ◽  
pp. 303-321 ◽  
Author(s):  
Abraham Neiman ◽  
Dale R. Eisenmann
Keyword(s):  
1988 ◽  
Vol 221 (4) ◽  
pp. 823-833 ◽  
Author(s):  
Takahisa Sasaki ◽  
Katsumi Tadokoro ◽  
Takaaki Yanagisawa ◽  
Shohei Higashi ◽  
Philias R. Garant

1990 ◽  
Vol 52 ◽  
pp. 301
Author(s):  
Hideaki Ogura ◽  
Hironari Wakamatsu ◽  
Keiichi Ohya ◽  
Shiro Mataki
Keyword(s):  

2006 ◽  
Vol 51 (6) ◽  
pp. 464-470 ◽  
Author(s):  
Kuochung Tung ◽  
Haruko Fujita ◽  
Yasuo Yamashita ◽  
Yuzo Takagi
Keyword(s):  

1979 ◽  
Vol 58 (2_suppl) ◽  
pp. 950-979 ◽  
Author(s):  
C.P. Leblond ◽  
H. Warshawsky

Enamel formation was reviewed by morphology and radioautography in rat incisors. Labeled amino acids and sugars were used as matrix precursors whereas labeled calcium monitored mineral deposition. All ameloblasts synthesize organic material, but only cells in the zone of secretion release labeled matrix. The pattern of matrix deposition indicates that enamel rods are elaborated by Tomes' processes within cavities formed by interrod partitions. The latter are elaborated by cytoplasmic projections from adjacent ameloblasts. Initially - labeled matrix is added as a band near the cells. With time the label randomizes throughout the entire immature enamel and most of it is lost in the zone of maturation. However, a glycoprotein component attributed to remnants of Tomes' process membrane persists in mature enamel. Labeled calcium is incorporated into crystals which grow at a uniform rate throughout the entire layer of enamel in the zone of secretion and up to the middle of the zone of maturation. The ribbon-like crystals are built close to the cell membrane and elongate as the cell recedes. Crystal elongation occurs in the same location as new matrix is deposited; that is, rod crystals are related to Tomes' processes and interrod crystals, to cytoplasmic projections. The crystals grow to full size mainly by thickening and this growth presumably displaces the organic matrix.


1993 ◽  
Vol 274 (2) ◽  
pp. 413-419 ◽  
Author(s):  
J. Kirkham ◽  
C. Robinson ◽  
J. K. Phull ◽  
R. C. Shore ◽  
B. J. Moxham ◽  
...  

1987 ◽  
Vol 35 (4) ◽  
pp. 471-482 ◽  
Author(s):  
A H Salama ◽  
A E Zaki ◽  
D R Eisenmann

A modified Wachstein-Meisel medium containing lead or cerium as capturing ions was used to localize Ca2+-Mg2+ adenosine triphosphatase (ATPase; EC 3.6.1.3) in rat incisor ameloblasts during enamel formation. Sections representing different developmental stages were processed for electron microscopic cytochemistry. Distribution and intensity of the observed reaction product, which was almost exclusively associated with cell membranes, varied according to the stage of enamel formation. During the secretory stage, intense reaction product was evident along the entire plasma membrane of ameloblasts and papillary cells. The early transitional ameloblasts showed reaction product on their proximal and lateral cell membranes, but not distally. In late transitional (pre-absorptive) ameloblasts, distal cell membranes exhibited intense reaction product. During enamel maturation, smooth-ended ameloblasts showed reaction product proximally and laterally, but not distally. Ruffle-ended maturative ameloblasts exhibited intense reaction product along their lateral and distal membranes. The intensity of the latter was decreased but not eliminated by levamisole. In the transition from smooth-ended to ruffle-ended cells, the reaction product became evident distally, concomitant with the appearance of cell membrane invaginations. These data are consistent with a possible role for Ca2+-Mg2+ ATPase in controlling calcium availability at the enamel mineralization front.


Author(s):  
Andrew Kataba ◽  
Shouta M. M. Nakayama ◽  
Hokuto Nakata ◽  
Haruya Toyomaki ◽  
Yared B. Yohannes ◽  
...  

Lead (Pb) is a metal toxicant of great public health concern. The present study investigated the applicability of the rat incisor in Pb exposure screening. The levels of lead in teeth (Pb-T) in the crown and root of incisors in laboratory Pb-exposed Sprague Dawley rats were quantified using inductively coupled plasma mass spectrometry (ICP-MS). The crown accumulated much Pb-T than the root of the Sprague Dawley rat incisor. The levels of lead in blood (Pb-B) were positively correlated with the Pb-T in the crown and root incisors of the Sprague Dawley rats. As an application of the Pb-T crown results in experimental rats, we subsequently analyzed the Pb-T in the crown incisors of Pb-exposed wild rats (Rattus rattus) sampled from residential sites within varying distances from an abandoned lead–zinc mine. The Pb-T accumulation in the crown of incisors of R. rattus rats decreased with increased distance away from the Pb–Zn mine. Furthermore, the Pb-T was strongly correlated (r = 0.85) with the Pb levels in the blood. Laser ablation ICP-MS Pb-T mappings revealed a homogenous distribution of Pb in the incisor with an increased intensity of Pb-T localized in the tip of the incisor crown bearing an enamel surface in both Sprague Dawley and R. rattus rats. These findings suggest that Pb-T in the crown incisor may be reflective of the rat’s environmental habitat, thus a possible indicator of Pb exposure.


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