共查询到20条相似文献,搜索用时 15 毫秒
1.
Y. Seino K. Yamaoka M. Ishida H. Yabuuchi M. Ichikawa H. Ishige H. Yoshino L. V. Avioli 《Calcified tissue international》1982,34(1):265-269
Summary This study presents measurements of serum vitamin D metabolites, calcium and phosphorus as well as measurements of the equilibrium
dissociation constant for duodenal 1,25(OH)2D3 receptor in 15-, 18-, 19-, and 20-day chick embryos in comparison to that in 1- and 118-day-old chicks and to vitamin D-deficient
chicks. The present results showed that: (a) serum 1,25(OH)2D and 24,25(OH)2D levels rise from 15 and 18 to days 19 and 20 of embryonic development while serum phosphate levels are stable; (b) serum
calcium levels rise at hatching to adult levels; (c) the duodenal 1,25(OH)2D3 receptor is detectable in 15-day-old embryo and has a Kd similar to that of 118-day-old vitamin D-replete chicks; and (d)
the activity of 1,25(OH)2D3 receptor in chick duodenal cytosol is maximal at hatching. 相似文献
2.
Yusuke Tsukamoto M.D. 《Journal of bone and mineral metabolism》1991,9(1):54-57
Conclusion In our experience, after a few months of therapy, every patient showed a marked improvement in both X-ray abnormalities derived
from osteitis fibrosa and symptoms of renal osteodystrophy, especially bone pain, unless the serum phosphorus level was very
high. The effectiveness of this therapy on the suppression of PTH secretion apparently depends on the initial PTH level, and
also on the size of the gland itself. One of the major current difficulties in this therapy is the prevention of hypercalcemia
when calcium carbonate is used. The calcium concentration of the dialysate must be reduced to 2.5 mEq/l not only for pulse
therapy, but also for conventional therapy by vitamin D with calcium carbonate. Parathyroidectomy should be indicated only
for the patient who does not respond to pulse therapy. 相似文献
3.
G. G. Langston L. D. Swain Z. Schwartz F. Del Toro R. Gomez Barbara D. Boyan 《Calcified tissue international》1990,47(4):230-236
Summary Vitamin D3 metabolites have been shown to affect proliferation, differentiation, and maturation of cartilage cells. Previous studies
have shown that growth zone chondrocytes respond primarily to 1,25(OH)2D3 whereas resting zone chondrocytes respond primarily to 24,25(OH)2D3. To examine the role of calcium in the mechanism of hormone action, this study examined the effects of the Ca ionophore A23187,
1,25(OH)2D3, and 24,25(OH)2D3 on Ca influx and efflux in growth zone chondrocytes and resting zone chondrocytes derived from the costochondral junction
of 125 g rats. Influex was measured as incorporation of45Ca. Efflux was measured as release of45Ca from prelabeled cultures into fresh media. The pattern of45Ca influx in unstimulated (control) cells over the incubation period was different in the two chondrocyte populations, whereas
the pattern of efflux was comparable. A23187 induced a rapid influx of45Ca in both types of chondrocytes which peaked by 3 minutes and was over by 6 minutes. Influx was greatest in the growth zone
chondrocytes. Addition of 10−8–10−9 M 1,25(OH)2D3 to growth zone chondrocyte cultures results in a dose-dependent increase in45Ca influx after 15 minutes. Efflux was stimulated by these concentrations of hormone throughout the incubation period. Addition
of 10−6–10−7 M 24,25(OH)2D3 to resting zone chondrocytes resulted in an inhibition in ion efflux between 1 and 6 minutes, with no effect on influx during
this period. Efflux returned to control values between 6 and 15 minutes.45Ca influx was inhibited by these concentrations of hormone from 15 to 30 minutes. These studies demonstrate that changes in
Ca influx and efflux are metabolite specific and may be a mechanism by which vitamin D metabolites directly regulated chondrocytes
in culture. 相似文献
4.
To clarify the state of vitamin D production by the developing kidney, firstly, we measured serum levels of 1,25(OH)2D and 24,25(OH)2D in humans of different ages (pregnant and nonpregnant women, adult males, children and newborn infants) and secondly, we measured 1- and 24-hydroxylase activity in the kidney mitochrondria of rats at different ages. The mean serum levels of 1,25(OH)2D in pregnant women, cord blood and newborns were significantly higher than those in children and non-pregnant women and adult males. In newborns, the level increased with gestational age. Synthesis of 1,25(OH)2D was, at least in part, under the control of the fetus and newborn, rather then being solely a reflection of the conditions prevailing in the mother. The 1-hydroxylase activity in mitochondria was highest in the 1- to 2-month-old rats, and it decreased gradually thereafter. The change in 1-hydroxylase activity with age was due to a change in the Vmax of the system. 相似文献
5.
Summary Calvarial bones from hypophosphatemic (Hyp) mice and normal littermates were cultured in a chemically defined medium to determine:
(a) the effect of medium phosphate (Pi) concentration (1, 2, and 3 mM) on collagen synthesis; (b) the effect of 1,25-dihydroxycholecalciferol
[1,25(OH)2D3] (10−12M–10−7M) on collagen synthesis; and (c) whether bone responsiveness to 1,25(OH)2D3 was affected by changes in medium Pi concentration. Bone collagen synthesis was evaluated by measuring [3H]hydroxyproline formation. The distribution of labeled hydroxyproline between bone explant and culture medium (total and
dialyzable fraction) was studied. These experiments confirm that 1,25(OH)2D3 inhibits specifically bone collagen synthesis in vitro. We did not detect any effect of medium Pi concentration on basal
collagen synthesis but were able to demonstrate that lowering medium Pi concentration increased the 1,25(OH)2D3-induced inhibition of collagen synthesis. Bones from both genotypes responded to 1,25(OH)2D3, but modulation of this response by changes in Pi concentration was altered in Hyp bone as, in contrast to normal bone, its
response to 1,25(OH)2D3 was unaffected when medium Pi concentration was decreased from 3 to 2 mM. These findings support the hypothesis of an altered
response of bone to 1,25(OH)2D3 in the Hyp mouse. 相似文献
6.
Stavros C. Manolagas Jean Abare Leonard J. Deftos 《Calcified tissue international》1984,36(1):153-157
Summary We have used cultured osteoblastlike rat osteogenic sarcoma cells (ROS 17/2) which have receptors for 1,25(OH)2D3 and for glucocorticoids, and have examined the modulation of the 1,25(OH)2D3 receptor by the potent glucocorticoid triamcinolone acetonide. We report that triamcinolone acetonide caused an increase
of the 1,25(OH)2D3 receptor concentration in these cells but it did not affect the affinity of the receptor to 1,25(OH)2D3; this phenomenon occurred in a dosedependent fashion for triamcinolone (10−9 to 10−7 M) with a maximum increase of 1,25(OH)2D3 receptor concentration of ⋍twofold. During the culture period, the 1,25(OH)2D3 receptor concentration was altered both in untreated as well as in triamcinolone-treated cells, being highest at the early
logarithmic phase and diminished progressively as cells approached confluence. However, throughout the culture period, the
1,25(OH)2D3 receptor concentration was higher in the triamcinolone-treated cells. 相似文献
7.
Dr. Pierre J. Marie Monique Hott Marie-Thérèse Garba 《Calcified tissue international》1985,37(3):268-275
Summary The purpose of this study was to evaluate whether the 1,25(OH)2D3-induced increased bone mineralization in the mouse occurs in response to stimulation of bone resorption. In order to inhibit
bone resorption, 35-day-old mice were given 16 μmol/kg/day of (3-amino-1-hydroxypropylidene)-1,1-bisphosphonate (AHPrBP) for
10 days, the first injection occurring 3 days prior to the continuous infusion of 0.06, 0.13, or 0.20 μg/kg/day of 1,25(OH)2D3 for 7 days. Two groups of mice were treated with AHPrBP or 1,25(OH)2D3 alone. The skeletal changes were assessed by histomorphometric study of caudal vertebrae after double3H-proline and double tetracycline labelings for evaluation of the matrix apposition rate (MaAR) and mineral apposition rate
(MiAR), respectively. Treatment with AHPrBP alone or combined to 1,25(OH)2D3 decreased the number of acid phosphatase-stained osteoclasts and reduced the endosteal MaAR and MiAR and the amount of osteoid.
When given alone, 1,25(OH)2D3 increased serum calcium above normal, enhanced the number of histochemically active osteoclasts, and stimulated the endosteal
MiAR. Pretreatment with AHPrBP blocked both the increase in serum calcium and the stimulation of the MiAR induced by 1,25(OH)2D3 infusion though serum 1,25(OH)2D3 levels rose according to the dose given. The results show that 1) the serum calcium and the bone resorbing responses to 1,25(OH)2D3 infusion are prevented by pretreatment with AHPrBP, and 2) the stimulatory effect of 1,25(OH)2D3 on the mineralization rate is blocked when bone resorption is inhibited. The data indicate that 1,25(OH)2D3 promotes bone mineralization in the mouse mainly in response to stimulation of bone resorption. 相似文献
8.
J. P. T. M. van Leeuwen H. A. P. Pols J. P. Schilte T. J. Visser J. C. Birkenhäger 《Calcified tissue international》1991,49(1):35-42
Summary The effects of epidermal growth factor (EGF) on basal 1,25-dihydroxyvitamin D3 (1,25-(OH)2D3) receptor level and on parathyroid hormone (PTH)-induced 1,25-(OH)2D3 (OH)2D3 receptor up-regulation were studied in the phenotypically osteoblastic cell line UMR 106. EGF in concentrations exceeding
0.1 ng/ml reduced the number of 1,25(OH)2D3 binding sites without changing the binding affinity. Maximal reduction was 30% at about 1 ng/ml. This reduction was independent
of a change in cAMP content. EGF dose-dependently attenuated both PTH-induced 1,25(OH)2D3 receptor up-regulation and PTH-stimulated cAMP production without and effect on the ED50 of the PTH effects. For both PTH responses the IC50 and the maximal effective dose were similar, 0.1 ng/ml an 1 ng/ml EGF, respectively. Reduction was first seen at 0.01 ng/ml
EGF. At this concentration. EGF reduced PTH-stimulated 1,25-(OH)2D3 receptor binding without an inhibition of the cAMP response. Time-course studies with 1 ng/ml EGF revealed that at 2 h preincubation
EGF reduced the heterologous up regulation by PTH, and maximal inhibition was seen after 4 h. In contrast, PTH-stimulated
cAMP production was just significantly inhibited only after 6 h, with 60% inhibition after 24 h preincubation. The effects
of prostaglandin E2 and forskolin on both 1,25(OH)2D3 binding and cAMP production were inhibited in a similar fashion. On the other hand, dibutyryl cAMP- and 3-isobutyl-1-methylxanthinestimulated
1,25(OH)2D3 binding were not affected by EGF. Taken together, our results demonstrate that EGF reduces both the basal number of 1,25(OH)2D3 binding sites and the heterologous up-regulation of the 1,25(OH)2D3 receptor. The current data suggest that EGF reduces heterologous upregulation of the 1,25(OH)2D3 receptor independent of as well as dependent on the cAMP messenger system. The EGF effect is not primarily located at the
PTH receptor, at cAMP phosphodiesterase, or at protein kinase A level. 相似文献
9.
Summary Parathyroid hormone (PTH)-stimulated cyclic adenosine monophosphate (cAMP) in rat osteoblastlike (OB) cells has been shown
to be modulated by steroid hormones; glucocorticoids are known to increase the level, while the effects of 1,25(OH)2D3 are inhibitory. In the present study, we found that the PTH-stimulated cAMP responses are similar in neonatal mouse and fetal
rat OB cells. Dexamethasone (0.13–13nM) augmented PTH-stimulated cAMP in both species. Mouse cells showed a higher maximal
response to dexamethasone (100% increment) than rat cells (60–70% increment) with similar sensitivity to dexamethasone (ED50 ∼ 1.0 nm). On the other hand, 1,25(OH)2D3 decreased PTH-stimulated cAMP, but the effect required pharmacological levels of hormone; mouse cells responded at a lower
dose (1.3 nM) and were more sensitive than rat cells (responded at 13 nM) to 1,25(OH)2D3 treatment. Introduction of physiological concentrations of 1,25(OH)2D3 (0.013–1.3 nm) in addition to dexamethasone (13 nM) resulted in a synergistic enhancement of PTH-stimulated cAMP in rat cells.
In contrast, a dose-dependent antagonistic effect was observed in mouse cells. In summary, our findings demonstrate species
and concentration-dependent differences in hormonal responses to 1,25(OH)2D3 and a complex interplay among PTH, dexamethasone, and 1,25(OH)2D3. 相似文献
10.
The effects of retinoic acid (RA), and calcitriol are mediated by specific nuclear receptors (RARs and VDR, respectively). Induction of RAR and VDR responsive elements in target genes requires a cofactor, the retinoid-X-receptor (RXR), with its ligand 9-cis RA. We have previously demonstrated the expression of RARs and RXRs in osteoblasts, and herein investigated the effects of the retinoids all-trans RA and 9-cis RA alone and combined with calcitriol on bone resorption in vitro, measured by 45Ca-release from prelabeled neonatal mouse calvarial bones. All-trans RA and 9-cis RA were powerful stimulators of bone resorption and essentially equipotent. At threshold concentrations (1 nM) both 9-cis RA and at-RA markedly inhibited the resorption induced by calcitriol (1 pM). The findings are compatible with a physiological role for retinoids in bone metabolism. 相似文献
11.
Dr K. Sakhaee A. Zisman J. R. Poindexter J. E. Zerwekh C. Y. C. Pak 《Osteoporosis international》1993,3(4):209-214
It was previously shown that the stimulation of intestinal calcium absorption by exogenous 25-hydroxyvitamin D (25-OHD) in postmenopausal women with osteoporosis was attenuated when thiazide was added, probably due to the suppression of endogenous synthesis of 1,25-(OH)2 vitamin D (1,25-(OH)2D). To test whether the above attenuation could be averted if exogenous 1,25-(OH)2D replaced 25-OHD, 10 women with postmenopausal osteoporosis participated in a three-phase study comprising control (pretreatment), treatment with 1,25-(OH)2D 0.5 µg/day for 4 weeks, and combined 1,25-(OH)2D and trichlormethiazide (TZ) 2 mg/day for 4 weeks. The 1,25-(OH)2D treatment significantly increased serum 1,25-(OH)2D from 60±7.2 (SD) to 154±48 pmol/1, fractional intestinal calcium absorption () from 0.386 ±0.055 to 0.613±0.081, and urinary calcium from 3.7±0.8 to 6.6±1.9 mmol/day. Addition of TZ significantly reduced urinary calcium from 6.6±1.9 to 4.8±1.3 mmol/day, without changing (0.613±0.081 to 0.584±0.070), serum calcium or 1,25-(OH)2D (154±48 to 154±38 pmol/1). Thus, estimated calcium balance (absorbed minus urinary calcium, increased marginally to +5.6 mmol/day on 1,25-(OH)2D alone (p=0.028) and significantly to +6.8 mmol/day on 1,25-(OH)2D+TZ, from the control value of +4.0 mmol/day. Seven patients who were treated long-term with combined 1,25-(OH)2D and TZ for 11–29 months maintained their a (0.593±0.099) and a marginally more positive estimated calcium balance (+6.4 mmol/day,p=0.025 from the control phase). Moreover, there was a stability of bone density of radial shaft, femoral neck, and lumbar spine. In conclusion, when exogenous 1,25-(OH)2D is provided, TZ does not lower serum 1,25-(OH)2D and in patients with postmenopausal osteoporosis. Thus, the hypocalciuric action of TZ may lead to improved calcium balance and may potentially attenuate further bone loss. 相似文献
12.
Summary Rachitic rats, maintained on diets with low or normal P contents, were given daily intraperitoneal doses of 1,25(OH)2D3 or 25OHD3 at levels of 100 or 200 ng. Plasma chemistry was measured and the ash content and histological appearance of the bones investigated.
Using labeled material it was shown that the dosing levels of 1,25(OH)2D3 employed ensured a higher than normal plasma concentration of that metabolite over the period between doses. 1,25(OH)2D3 was not as effective as 25OHD3 in raising bone ash or reducing the amount of osteoid. The difference between the effects of the metabolites was evident
at both dietary P levels, but more marked at the higher P level. In contrast, the metabolites reduced the width of the epiphyseal
plate to an approximately similar degree, and this is possibly the reason why there are discrepancies between previous reports
of the effectiveness of 1,25(OH)2D3 compared with 25OHD3 or vitamin D3. Dosing with 1,25(OH)2D3 failed to maintain a constant plasma Pi value over the period between doses in animals fed the low P diet. 相似文献
13.
Dr. Helen Czernobilsky Stephan Scharla Heinrich Schmidt-Gayk Reinhard Ziegler 《Calcified tissue international》1988,42(1):5-12
Summary 1,25(OH)2D3, 25OHD3, and intact parathyroid hormone, as well as various parameters of calcium-phosphorus metabolism were measured in 38 patients
with Graves' disease (GD) and in 24 patients with toxic nodular goiter (TNG). Plasma 1,25(OH)2D3 levels were lower in GD patients (82 ±29 pmol/liter) than in those with TNG (155±32 pmol/liter) (P<0.0005). The mean value of 1,25(OH)2D3 in 45 controls was intermediate between the two groups of patients (140±41) and the difference was statistically significant.
GD patients before and after treatment had higher alkaline phosphatase (P<0.05), lower intact parathyroid hormone (PTH) (P<0.05), and lower 1,25(OH)2D3 levels (P<0.0005 in the hyperthyroid andP<0.01 in the euthyroid state) than TNG patients. We conclude that increased skeletal calcium resorption is due to elevated
levels of T3 causing suppression of 1,25(OH)2D3 production and of PTH levels in both groups of patients albeit of different degrees. Furthermore, we postulate that the profound
suppression of 1,25(OH)2D3 in GD is secondary to an immune-mediated phenomenon. 相似文献
14.
Summary A closed tibial fracture, which was controlled by an intramedullary stainless steel pin, was created in 16 rabbits. Eight
rabbits were treated with 75 ng of 1,25(OH)2D3 daily as subcutaneous (s.c.) injections. After three weeks, the fractured tibia resisted a force of 101,7±21.0 Newtons in
the control group and 57.3±8.0 Newtons in animals given 1,25(OH)2D3 (m±SE,P<0.05). In another group of eight rabbits, the left hindleg was immobilized in a plastic splint. Four rabbits were given 75
ng of 1,25(OH)2D3/day s.c. and the effect of immobilization was studied on the calcaneus. Bone ash/cm3 of the calcaneus on the immobilized side was decreased by 11±2% in control rabbits and by 20±2% in the group treated with
1,25(OH)2D3 indicating a more advanced immobilization osteoporosis (m±SE,P<0.05), which was also demonstrated by studies of bone density. Eighteen rabbits were used in a study of the effects of 1,25(OH)2D3 on the development of prednisolone osteoporosis. The dose of prednisolone was 2.5 mg per day, given by the oral route. After
four months, the density of the femur was 1.53±0.02 g/cm2 in control rabbits and 1.42±0.01 in prednisolonetreated animals (P<0.01). In rabbits additionally given 1,25(OH)2D3, the mean value for bone density was further lowered (n.s.). It appears that 1,25(OH)2D3 exaggerates disuse osteoporosis and prednisolone osteoporosis and impairs fracture healing in rabbits. These results differ
from what has been shown earlier with 1,25(OH)2D3 treatment in the rat. 相似文献
15.
Socorro Vargas Roger Bouillon Hugo Van Baelen Dr. Lawrence G. Raisz 《Calcified tissue international》1990,47(3):164-168
Summary Vitamin D and its metabolites are tightly bound to the serum vitamin D-binding protein (DBP) and only the free hormone is
considered to be physiologically active. On the other hand, DBP could interact with cell membranes and even favor its intracellular
entry. The present study was undertaken to examine the effects of DBP on bone resorption stimulated by 1,25-dihydroxyvitamin
D3 [1,25(OH)2D3]. Forelimb bones from 19-day-old fetal rats were cultured for 5 days in the presence of purified human or rat serum albumin
(hSAP or rSAP) and 1,25(OH)2D3, with or without human or rat DBP (hDBP or rDBP). Bone resorption was assessed by measuring the release of previously incorporated45Ca. We found that the resorptive response to 1,25(OH)2D3 was minimally altered by hDBP (5 μM). The minimal effects of hDBP on 1,25(OH)2D3 activity on rat bones might be explained by a 6-fold lower affinity of hDBP (1.1×107 M−1) than rDBP (5.9×107 M−1) for 1,25(OH)2D3 or by species differences in cellular recognition of DBP. In a homologous rat system, however, rDBP at low (0.5 μM) or physiological
(5 μM) concentration significantly decreased 1,25(OH)2D3-induced bone resorption. These data therefore support the hypothesis that free rather than DBP-bound 1,25(OH)2D3 is physiologically important. 相似文献
16.
17.
目的 探讨1,25(OH)2D3对Th17细胞分化的体外抑制作用.方法 通过对分离出的脾淋巴细胞进行CD4+T细胞分选,将不同浓度的1,25(OH)2D3加入到CD4+T细胞中并在诱导因子的作用下诱导其分化.通过ELISA检测培养上清中IL-17A和IL-22的浓度;流式细胞仪分析Th17细胞的比例及RT-PCR检测Th17细胞分化的转录因子的表达.结果 培养上清ELISA检测显示:与对照组相比,1,25(OH)2D3组的IL-17A和IL-22浓度随着加入1,25(OH)2D3浓度的增大而呈现逐渐降低的现象,差异且具有统计学意义(P<0.01);流式结果显示:诱导分化后对照组Th17细胞比例最多,1,25(OH)2D3组处理后Th17细胞比例降低,且呈剂量依赖性;RT-PCR检测显示:与对照组相比,1,25(OH)2D3组IL-17A、IL-22,RORγt和RORα 表达量随着剂量的增加而逐渐降低,并具有统计学意义(P< 0.01).结论 体外实验表明,1,25(OH)2D3具有抑制Th17细胞分化的作用,表现为Th17细胞比例、分泌的细胞因子及特异的转录因子表达均减少. 相似文献
18.
Summary Previous work has shown that vitamin D3 or 1,25-dihydroxy-vitamin D3 affect calcium content and fluxes in mitochondria of chick skeletal musclein situ. Studies were performed to investigate whether these effects are related to variations in the Ca2+ transport properties of mitochondrial membranes. Mitochondria isolated from skeletal muscle of vitamin D-deficient chicks
and chicks dosed with 1,25(OH)2D3 for 3 or 7 days (50 ng/day) were employed. No changes in the rate and affinity for calcium of the Ruthenium Red-sensitive
Ca2+ uptake system were detected after treatment with 1,25(OH)2D3. The metabolite did not cause either modifications in Ca2+ efflux from mitochondria preloaded with the cation induced by Na+ or blockage of mitochondria energy supply. Prior treatment of animals with vitamin D3 was also without effects. However, a significant stimulation of Ca2+ uptake by intact muscle preparations from the same experimental animals was observed in response to treatment with 1,25(OH)2D3
in vivo (50 ng/day, 3 days) orin vitro (10−10 M, 60 minutes). In addition, the Ca content of muscle mitochondria was markedly diminished in chicks treated with the sterol.
It is suggested that the effects of 1,25(OH)2D3 on muscle mitochondrial Ca metabolism may be secondary to changes in cytoplasmic Ca2+. 相似文献
19.
Summary Cultured mouse kidney cells grown in serum-free medium were used to assess the metabolism of 25-hydroxyvitamin D3 in the presence of simulated metabolic acidosis. Kidney epithelial cells isolated from 4–6 week old mice were grown to confluence
in a defined serum-free medium at pH 7.4. The confluent monolayers were incubated with tritiated 25-hydroxyvitamin D3 for 6 hours, the samples were extracted, and vitamin D metabolites were separated and quantitated by high pressure liquid
chromatography (HPLC). The pH of the incubation medium was set at 6.9, 7.1, 7.4, or 7.7 by adjusting the bicarbonate concentration,
using chloride as the balancing anion at constant Pco2. When pH was altered at the beginning of the 6 hour assay, production of 1,25-dihydroxyvitamin D3 was the same at each pH. More prolonged pH perturbation for a total of 30 hours likewise had no influence on 1,25-dihydroxyvitamin
D3 production. These results confirm that intact mammalian kidney cells in serum-free culture possess an active 25-hydroxyvitamin
D3-1-hydroxylase and that the activity of the enzyme is unaffected by pH over the range 6.8–7.7. In experiments where acidosis
has been shown to alter 1,25-dihydroxyvitamin D3 production, the mechanism was probably indirect. 相似文献
20.
Yasunori Sakakura Naoki Fujiwara Kiyoto Ishizeki Tokio Nawa 《Calcified tissue international》1988,43(1):46-49
Summary Mandibular first molars from 17-day-old mouse embryos were cultured for 2 and 4 days in alpha-MEM supplemented with 10% newborn
bovine serum containing 0.02% ethanol or 0.1, 1.0 or 10 ng/ml 1,25-(OH)2D3. After embedding, every 6th section was stained and mitotic features of inner dental epithelium (IDE) and dental papilla
cells (DP) were counted under a light microscope. On the 2nd day, no significant differences were observed in the IDE and
DP mitotic indexes among the control, ethanol, and the three vitamin D groups. On the 4th day, the indexes for all groups
decreased. But the IDE indexes for all vitamin D groups were significantly different from those for the control (P<0.01) and
ethanol (P<0.05) groups, whereas the DP index was significant (P<0.05) only in the 10 ng/ml vitamin D group. The present results
suggest that vitamin D3 may have an influence on cell proliferation of IDE and DP in mouse embryonic molarsin
vitro. 相似文献