Collagen Fibers In Group Research Articles

An examination of the effect of exercise and creatine monohydrate on oral tissues.

Although physical exercise is extremely important for health and a good lifestyle, it can trigger oxidative stress, inflammation, and muscle fatigue. The aim of this study was to determine changes in dental tissues and the mandible created by creatines monohydrate (CrM) supplementation together with low and high-intensity exercise (HIE). The study material comprised Balb/c male mices, which were separated into two groups for the application of low and HIE on a running band. CrM supplement was administered together with the exercise. At the end of the experiment period, dental tissue samples were surgically removed and examined histopathologically and immunohistochemically (TNF-α and lL-1β).As a result of the histopathological examinations, in the pulp, oedema, vascular congestion, and capillary dilatation were seen to be statistically significantly increased in the Group 3 mices that performed HIE compared to the control group (p = 0.001, p = 0.003, p = 0.001, respectively). A statistically significant increase was observed in periodontal ligament (PDL) degeneration, and disruption of the continuity and separation of collagen fibers in Group 3 compared to the control group (p = 0.001). In the immunohistochemical examination, TNF-α and IL-1β positivity was observed in Group 3, and this was significantly increased compared to the control group (p = 0.001, p = 0.000).Exposure of the mices to low and HIE caused histological and immunohistochemical changes in dental pulp and PDL, and it was determined that the use of CrM could have a protective effect against these changes. RESEARCH HIGHLIGHTS: The results of this study showed negative effects of HIE in the dental pulp and PDL, which play an important role in dental health. CrM was seen to be effective in preventing these negative effects.

Repairing Effect of Platelet Enriched Plasma on Tendon Healing

To explore the repairing effect of platelet-rich plasma (PRP) on tendon (AT) healing, and provide evidence for PRP therapy to treat tendon-related diseases, 32 New Zealand white rabbits were selected to construct tendinopathy animal model. Leukocyte-rich Platelet-Rich Fibrin (Lr-PRP) and Leukocyte-poor Platelet-Rich Fibrin (Lp-PRP) were prepared, whose biological effects on tendon stem cells (TSCs) were explored. Rabbits were divided into control group, low, medium, and high dose groups regrading concentration of Lp-PRP. The number of fibroblasts, collagen fiber content, tubuloglomerular feedback-β1 (TGF-β1) expression, and biomechanical properties were compared at 15 and 30 days after operation. The results showed that Collagen-III (CoI-III) protein expression levels, interleukin-β (IL-β), and interleukin-6 (IL-6) levels in the Lp-PRP group were significantly higher than Lr-PRP group (P < 0.05). Fibroblasts and collagen fibers in group II and III were significantly higher versus group C 15 and 30 days after operation (P < 0.05). Fibroblasts and of collagen fibers in group III were significantly higher versus group II (P < 0.05). Expression of TGF-β1 in groups II and III was significantly higher than that in group C 15 days after operation (P < 0.05). Tensile load of AT repair site in group III was significantly higher than group C 30 days after operation (P < 0.05). Platelet plasma concentration had a certain repair effect on tendon injury and can effectively improve the quality of healing. In addition, Lp-PRP was better than Lr-PRP in tissue healing. When the concentration of Lp-PRP was 100%, the repair effect was the best.

TGF-β1/ERK/CTGF pathway involved in effect of acupuncture on exercise-induced skeletal muscle fibrosis

To observe the changes of the skeletal muscle fibrosis and changes of transforming growth factor-β1(TGF-β1)/ extracellular signal-regulated kinase (ERK) / connective tissue growth factor (CTGF)pathway in rats after long-term eccentric exercise and acupuncture intervention, so as to explore the mechanism of acupuncture in regulating exercise-induced skeletal muscle fibrosis. A total of 30 male SD rats were randomly divided into normal control, exercise and acupuncture group, with 10 rats in each group. The rat model of skeletal muscle fibrosis was established by eccentric exercise for 3 weeks. After exercise trained every time, the rats of the acupuncture group received acupuncture stimulation by holding the acupuncture needle to obliquely and longitudinally penetrate the ventral part of triceps of the lower leg along its lateral side, followed by retaining the needle for 2 min. Changes of the collagen fibers in each group was observed by scanning electron microscope. The expressions of Collagen Ⅰ, TGF-β1, phosphated (p)-ERK/ERK and CTGF proteins were detected by Western blot. After 3 weeks of eccentric exercise and acupuncture, the fibrosis and deposition of collagen fibers in the exercise group were significantly higher than that in the normal control group,the degree of fibrosis in the acupuncture group was significantly lower than that in the exercise group. Compared with the normal control group, the expression levels of Collagen Ⅰ, TGF-β1, CTGF and p-ERK/ERK in the exercise group was significantly higher (P<0.01，P<0.05). After EA interventions, the increased levels of the above indicators were significantly reversed (P<0.05，P<0.01) apart from p-ERK/ERK which had a downward trend, but the difference was not statistically significant. The accumulation of chronic sports injury can lead to the deposition of collagen fibers in skeletal muscle, which leads to the fibrosis of skeletal muscle. Acupuncture can inhibit skeletal muscle fibrosis via down-regulating TGF-β1/ERK/CTGF signaling pathway.

Distribution of spleen connective tissue fibers in diabetic and vitamin C treated diabetic rats

ABSTRACT We investigated the distribution of connective tissue fibers in diabetic and vitamin C treated diabetic rat spleen. Rats were divided into three groups: group A, control; group B, diabetic; group C, vitamin C treated diabetic. Diabetes was induced by streptozotocin. Vitamin C was administered intragastrically for 21 days. Spleen tissues were examined by light microscopy after staining with Masson’s trichrome, Gomori silver impregnation and van Gieson. In group B, we found accumulation of collagen fibers in the trabeculae, in the capsule and around the central artery and splenic sinusoids. Splenic cord thickening due to fibrosis was observed. Reticular fibers accumulated principally in the white and red pulps of the spleen and focal reticular fiber thickening was observed in the dense fiber areas. Partial elastic fiber rupture was observed among the fibers of the elastic lamina of the arteries in the hilum. By contrast, the distribution of collagen fibers in group C was similar to group A. Collagen fiber accumulation was decreased in group C compared to group B. We found little reticular fiber thickening in group C and elastic fibers maintained their integrity and were better organized than in group B. Our findings suggest that appropriate doses of vitamin C may exert beneficial effects on the structure of the connective tissue fibers in the diabetic spleen.

Histopathological alterations of the intrinsic tongue muscles following zoledronic acid treatment in a rat model.

Bisphosphonates (BPs) are widely used as anti-bone-resorptive agents. Despite the great benefits of BPs, they may cause local and systemic adverse side effects. The aim of this study was to evaluate the histopathological effect zoledronic acid (ZA), which belongs to BPs, has on the intrinsic tongue muscles in a rat model. A total of 30 adult male albino rats were divided into 3 groups (10 rats each): group I served as a control; group II was given an intraperitoneal (i.p.) injection of 0.2 mg/kg of ZA once per week for 3 weeks; and group III received the same dosage of ZA, but for 8 weeks. After the animals were euthanized, the tongue tissue was dissected and examined histologically, histochemically and immunohistochemically. Histologically, a normal architecture of the muscle fascicles was observed in the control group. Group II showed degenerated muscle fibers with an indistinct sarcolemma. In group III, the muscle fibers were degenerated with severe sarcoplasmic dissolution. The histochemical examination using Masson's trichrome (MT) demonstrated a significant increase in collagen fibers in groups II and III as compared to the control group. The immunohistochemical results revealed a statistically significantly higher expression of nuclear factor kappa B (NF‑κB) in the ZA-treated groups (II and III) as compared to the control group, with the highest mean value recorded in group III. Zoledronic acid induced histopathological changes to the intrinsic tongue muscles, and this effect was exaggerated with a longer duration of administration.

Role of Acupoint Area Collagen Fibers in Anti-Inflammation of Acupuncture Lifting and Thrusting Manipulation.

The role of the acupoint area collagen fibers in the efficacy of acupuncture lifting and thrusting (L&T) manipulation will be explored in this paper. 30 male NZW rabbits were randomly divided into 6 groups: sham operation group (Group N), model group (Group M), acupuncture without manipulation group (Group W), acupuncture L&T manipulation group (Group A), collagenase pretreatment group (Group JM), and collagenase pretreatment + acupuncture L&T manipulation group (Group JA). The bacterial endotoxin was used to generate the rabbit fever models. Acupuncture was applied at IL-11. The levels of IL-1β, TNF-α, and IL-4 and the rectal temperature were measured at 2 h, 4 h, and 6 h after modeling and the collagen fiber morphology at acupoint area was observed after 6 hours. Results. As compared with Group N, the levels of IL-1β and TNF-α in Group M were significantly higher; the level of IL-4 was significantly lower (P < 0.05). As compared with Group M, IL-1β and TNF-α in Groups W and A were significantly lower and IL-4 was significantly higher (P < 0.05). As compared with Group W, IL-1β and TNF-α in Group A were lower and IL-4 was higher (P < 0.05). The collagen fiber in Group A was slightly rough, distorted, and fractured. As shown in studies, the endotoxin-induced inflammatory response can be significantly inhibited by acupuncture whose efficacy can also be significantly improved by the manipulations. Collagenase pretreatment may be the first receptor to the mechanical force of the L&T manipulation.

Intensity-dependent effect of treadmill running on typeIICollagen of knee articular cartilage in rats

Objective To investigate the effect of treadmill running with different intensities on typeⅡcollagen (Col2) of knee joint articular cartilages in rats. Methods A total of 48 adult Sprague-Dawley rats were randomly divided into a control (C) group, a low-intensity exercise (L) group, a moderate- intensity exercise (M) group and a high-intensity exercise (H) group, each of 12. Rats in three exercises groups were regularly trained on treadmill at low, moderate, and high intensities respectively. Eight weeks later, all the animals were sacrificed. The right tibial plateau samples were collected to observe collagen fibers under polarizing light microscopy, and the collagenⅡ content were examined using immunohistochemistry. The mRNA expression of biglycan (BGN), fibromodulin (FMOD) and Col2 was tested using the quantitative real-time reverse transcription-polymerase chain reaction. Results Compared with group C, collagen fibers in group L and M exhibited almost the same organization, whereas, alteration in organization and shape of collagen fibers was found in group H. Significantly lower content of type Ⅱ collagen was found in group H than that in group C. In comparison with group C, group L had significantly higher gene expression of Col2, whereas group H had significantly higher BGN mRNA expression. Conclusion Low- or moderate-intensity treadmill running appears to have beneficial effect on articular cartilages to maintain its integrity. High-intensity exercises induce lower content and disorder of type Ⅱ collagen in articular cartilages, but the self-healing of cartilage may still exist. Key words: Cartilage; Type Ⅱ collagen; Treadmill running; SLRPs

An effect of hyaluronan as abdominal post-operative anti-adhesive in dogs, macroscopic, laparoscopic and histopathological study

The aim of this study was to evaluate the effectiveness of hyaluronan as abdominal anti-adhesive. Sixteen healthy adult local breed dogs, aged between (1-2 years) and weighed (15-20) kg were used. They were divided into two equal groups. First group is considered as a control group (A), the second group is the hyaluronic acid group (B); both groups underwent celiotomy under the effect of general anesthesia (combination of ketamine-xylazine at the dose rate of 15mg /kg and 5mg/kg B.W, respectively). Three sero-muscular incisions were 3cm long created at anti-mesenteric border in the descending colon and sutured with simple continuous suture using4-0chromic cat gut, abdominal wall closed in routine manner, in control group. The same procedure was performed in group B but 2 ml of 1%sodium hyaluronate was applied intra peritoneally prior to abdominal closure. Evaluation of the results was based on macroscopic, laparoscopic and microscopic examinations. Macroscopic examination showed severe adhesions in all animals in both 7th, 30thpost operative days with high grade scores (grade 3-4), except in one animal there was no adhesion in group A. While in group B, all dogs had developed mild adhesion formation at 7thpost operative day in low grade score (grade, 1). By 30thpost operative day there was no adhesion (grade, zero) except mild adhesion, in one case between omentum and abdominal wall (grade, 1). Histopathological examination showed dense fibrous connective tissue with congested blood vessels and irregular collagen fibersin group A. While in group B there were fine bundles of cellular connective tissue, granulation tissue with mononuclear cells infiltration. There were significant differences (P&lt;0.05) between group B (1.00±0.00) and group A (3.50±0.28) at 7th, also at 30thpost operation a significant difference (P&lt;0.05) was found between group B (*0.25±0.25) and group A (2.75±0.94) macroscopically. Histopathological examination also revealed a significant difference (P &lt; 0.05) between group B(*1.00±0.81)and group A(2.75±0.50) at 7th and 30thpost operative days group B(*1.00±0.81) and group A(2.25±0.95).The study revealed, the effectiveness of hyaluronan in reducing intra-abdominal adhesions that occurred after abdominal surgery in dogs, in comparison with control group.

Histomorphometric assessment of the influence of low-level laser therapy on peri-implant tissue healing in the rabbit mandible.

The purpose of this study was to demonstrate the effect of low-level laser therapy (LLLT) on the peri-implant bone healing process in the rabbit mandible. LLLT has been shown to accelerate tissue repair and osseointegration of implants placed into the rabbit tibia. However, the beneficial effects of LLLT have never been tested in the rabbit mandible, which would more closely mimic the human situation. Twenty-four male New Zealand rabbits were randomly divided into four groups of six animals each. All animals had their left mandibular incisors extracted, followed by immediate insertion of a titanium dental implant in the fresh socket. Three groups received LLLT [aluminum-gallium-arsenide (AlGaAs), λ=830nm, 50 mW, continuous wave (CW)] at three different energy densities per treatment session (E-5, 5 J/cm(2); E-10, 10 J/cm(2); and E-20, 20 J/cm(2)). Irradiation was performed every 48 h for 13 days, totaling seven sessions. One group received sham treatment (controls). Histological sections were obtained from each of the 24 mandibles dissected, without first decalcifying the specimens, and were stained with hematoxylin and eosin and Picrosirius red for histomorphometric evaluation. Bone-to-implant contact (BIC), bone formation area, and collagen fiber area were assessed by light microscopy. Significant differences were found between group E-20 and all other groups (p<0.05). Histomorphometric evaluation showed significantly higher BIC and significantly more collagen fibers in group E-20. Photobiostimulation with LLLT at an energy density of 20 J/cm(2) per session had a significant positive effect on new bone formation around dental implants inserted in the rabbit mandible.

Use of Spongostan™ for Prevention of Cranial Subdural Adhesions Following Craniotomy in an Experimental Rabbit Model.

Spongostan™ is a sterile, water-insoluble, porcine gelatin absorbable sponge, which is widely used as a hemostatic material. The aim of this study is to test the anti-fibrotic capacity of Spongostan™, using a craniotomy model in an experimental rabbit model. Eighteen rabbits were divided into two groups: Each group consisted of 9 rabbits, duratomy plus Spongostan™ (group 1), and duratomy without Spongostan™ (group 2). Right parietal bone was removed via trephine and low speed drill and dura was opened. On the group 1 rabbits, an appropriate piece of Spongostan™ was meticulously placed under dural layer. On group 2 rabbits, same procedures were repeated without Spongostan™. Histological sections were taken from each group and evaluated for degree of fibrosis and collagen fibers. There was marked increase in number of fibroblasts and collagen fibers in group 2 rabbits, however most of the rabbits in Spongostan™ group demonstrate scarce histopathological findings for fibrosis. We conclude that an appropriately placed subdural Spongostan™ over cerebral tissue may prevent postoperative surgical adhesions after neurosurgical operations.

The effect of doxazosin on the expression of myocardial type I and type III collagen fibers in α1-adrenergic receptors antibody mediated diabetic rats

Objective To observe the effects of doxazosin on the expression of type [ and type 1 collagen fiber in autoantibodies against a-adrenergic receptors （ cq -AA） positive diabetic rats, and to investigate the protective mechanism of doxazosin on cardiomyopathy of diabetic rats. Methods After establishment of diabetes model with streptozocin, diabetic rats were randomly divided into diabetic group （ group A, n = 10 ）, doxazosin treated group （group B, n = 10） , oq-AA mediated group （group C, n = 8 ）,I-AA plus doxazosin treated group （group D, n = 8）. Group C and group D were injected cq-AA （ 100 μg/100 g） by caudal vein at 0, 4, 8, 12, and 16 weeks. Doxazosin （0.36 mg . kg-1.d-1 ） was administered by lavage for 16 weeks in group B and group D, and other groups were given the same volume of saline every day. Expressions of type I and typeⅢ collagen fibers in myocardium of left ventricle were detected by immunohistochemical staining. Pathological changes in the myocardium were observed by both light and electron microscopes. Changes in collagen fiber in myocardium were detected by Van Gieson staining. Results Among various groups, there was no significant difference in blood glucose levels （ P 〉 0.05 ）. After the intervention of doxazosin, body weight in group B and group D was greater than that of group A and group C （ P〈0.05 or P〈0.01 ）. Expression of type I and type II1 collagen fibers in myocardium in group D was lower than that in group C （ P〈0.05 ）. Expression of type I and type m collagen fibers in group B was lower than that in group A （ P〈 0.05 ） as well. Myocardial pathological changes in group C were most serious, showing reduced mitochondrial, vacuolar degeneration, and interstitial coUagen hyperplasia. Cardiomyopathy in group D and group B was less marked as compared with that in group C and group A, respectively. Myocardial collagen fiber in group C was significantly increased and showed poor alignment. Compared with group C, myocardial collagen deposition in group D was obviously reduced. Conclusions Doxazosin may suppress type I and type HI collagen expressions in myocardium of -1 -AA mediated diabetic rats, resulting in alleviation of myocardial fibrosis and protection of myocardium in diabeticrats. Key words: Doxazosin; Autoantibodies against cq-adrenergic receptors; Diabetic rats; Type 1 and type lUcollagen fiber

Effects of gene-activated matrix on autograft healing of anterior cruciate ligament

The aim of the present study was to observe the effects of gene‑activated matrix (GAM) on autograft healing of the anterior cruciate ligament. Forty‑eight rabbits were randomly divided into groups A and B. Rabbits were used to construct models of anterior cruciate ligament reconstruction. In group A, transforming growth factor (TGF)‑β1 was locally injected into the bone tunnel, while in group B, empty vector was administered. Tendons were removed to observe histology and ultrastructure and to evaluate biomechanics at postoperative months 1, 3 and 6. Optical microscopy revealed increased numbers of fibroblasts and collagen fibers in group A at each time‑point compared with B. Electron microscopy identified increased mitosis and abundance of fibroblasts, endoplasmic reticulum and mitochondria in group A at each time‑point compared with B. No significant difference was identified in the biomechanical parameters between the 2 groups at postoperative month 1. At postoperative months 3 and 6, maximum force and elastic modulus were greater in group A compared with group B (P<0.0.5). No significant differences in other biochemical parameters were observed at these time‑points. The healing ligament graft transfected with TGF‑β1 by GAM was observed to have improved tissue structure and biomechanical characteristics. The results of the current study may provide a theoretical basis for GAM application in ligament repair.

Characterization of the deposition of collagen fibers and Lithogenic potential in bladder of rats submitted to a sugar cane biopolymer graft

Suture materials are widely used in urology. The interaction of these materials with the extracellular matrix in the inflammatory process can be estimated by stereology of collagen fibers and the present study was designed to determine the behavior of the bladder tissue of rats to grafts of the biopolymer of sugar cane (BPCA), and the inflammation and intravesical stone formation compared to the polyglactin 910. 42 Wistar rats were divided in four groups: Group I (n = 10) rats submitted to bladder implantation of ~4-0 BPCA suture graft and euthanized at 4 weeks; Group II (n = 10) rats submitted to bladder implantation of 4-0 polyglactin 910 suture graft and euthanized at 4 weeks; Group III (n = 12) rats submitted to bladder implantation of ~4-0 BPCA suture graft and euthanized at 8 weeks; Group IV (n = 10) rats submitted to bladder implantation of 4-0 polyglactin 910 suture graft and euthanized at 8 weeks. Bladders collected at necropsy were analyzed for their weight and the presence of grafts and calculi. Sections were prepared for stereological analysis of collagen fibers. The bladder weight was higher in group I, particularly in the presence of bladder stones. The presence of the graft was observed in 100 % (group I), 80 % (group II), 91.6 % (group III) and 30 % (group IV); polyglactin 910 showed an absorption of 70 % in this period. The stereological analysis showed a higher volume density of collagen fibers in group I versus other groups (p < 0.001). The BPCA was a material with good integration into the bladder of rats; its absorption was slower than that of the polyglactin 910. The presence of urinary stones was lower in bladders with implantation of BPCA, particularly after 8 weeks. There was a greater initial inflammatory response to BPCA graft that was directly related to the increase in bladder weight and the presence of urinary stones, but that equalized the results of polyglactin 910 after 8 weeks.

Collagen changes and realignment induced by low‐level laser therapy and low‐intensity ultrasound in the calcaneal tendon

The treatment of calcaneal tendon injuries requires long-term rehabilitation. Ultrasound (US) and low-level laser therapy (LLLT) are the most used and studied physical agents in the treatment of tendon injuries; however, only a few studies examined the effects of the combination of US and LLLT. Therefore, the purpose of this study was to investigate which treatment (the exclusive or combined use of US and LLLT) most effectively contribute to tendon healing. This was a controlled laboratory study with 50 rats whose Achilles tendon was injured by direct trauma. The rats were randomly divided into five groups and treated for 5 consecutive days, as follows: group 1 (control) received no treatment; group 2 was treated with US alone; group 3 was treated with LLLT alone; group 4 was treated first with US followed by LLLT; and group 5 was treated first with LLLT followed by US. On the sixth post-injury day, the tendons were removed and examined by polarized light microscopy. The organization of collagen fibers was assessed by birefringence measurements. Picrosirius-stained sections were examined for the presence of types I and III collagen. There was a significantly higher organization of collagen fibers in group 2 (US) than in the control group (P = 0.03). The amount of type I collagen found in groups 2 (US), 3 (LLLT), and 5 (LLLT + US) was significantly higher than that in the control group (P <or= 0.01), but no significant differences were found between treatment groups. There were no differences in the amount of type III collagen between groups. Ultrasound, LLLT, and the combined use of LLLT and US resulted in greater synthesis of type I collagen; US was also effective in increasing collagen organization in the early stages of the healing process.

Effects of Cyclosporin, Phenytoin, and Nifedipine on the Synthesis and Degradation of Gingival Collagen in Tufted Capuchin Monkeys (Cebus apella): Histochemical and MMP‐1 and −2 and Collagen I Gene Expression Analyses

The purpose of this experimental study was to evaluate the collagen fiber distribution histologically after phenytoin, cyclosporin, or nifedipine therapy and to correlate it with collagen I and matrix metalloproteinase (MMP)-1 and -2 gene expression levels. Gingival samples from the canine area were obtained from 12 male monkeys (Cebus apella). The mesial part of each sample was assessed by reverse transcription-polymerase chain reaction, whereas the distal part was processed histologically for picrosirius red and hematoxylin and eosin stainings, as well as for collagen IV immunostaining. One week after the first biopsy, the animals were assigned to three groups that received daily oral dosages of cyclosporin, phenytoin, or nifedipine for 120 days. Additional gingival samples were obtained on days 52 and 120 of treatment from two animals from each group on the opposite sides from the first biopsies. Picrosirius red staining showed a predominance of mature collagen fibers in the control group. Conversely, there was an enlargement of areas occupied by immature collagen fibers in all groups at days 52 and 120, which was not uniform over each section. There was a general trend to lower levels of MMP-1 gene expression on day 52 and increased levels on day 120. Phenytoin led to increased levels of MMP-2 and collagen I gene expression on day 120, whereas the opposite was observed in the nifedipine group. Cyclosporin, phenytoin, and nifedipine led to phased and drug-related gene expression patterns, resulting in impaired collagen metabolism, despite the lack of prominent clinical signs.

仔ラット頭蓋骨形成機転に及ぼすフッ素イオンの影響

It has been suggested that releasing of calcium from calvaria into culture medium was inhibited by sodium fluoride. In this study, the investigation was carried out for the concept about the influence of fluorine on new bone formation of rats by injecting sodium fluoride to the rats. The experimental animals were divided into three groups.Group 1 was treated with a single daily dose of 0.11mg sodium fluoride for 3 days beginning from the 3rd day postnatally. Group 2 was treated with a single daily dose of 0.11mg sodium fluoride for 6 days also from the 3rd day postnatally. The control group was administered without sodium fluoride. The rats' calvaria were obtained on the 9th day postnatally.The results were obtained as follows.1. The daily body weight changes showed no significant differances among the 3 groups.2. The fluorine that deposited in every mg tissus of rats' calvaria showed a 0.46±0.02μg in group 1, a 0.65±0.02μg in group 2 and a 0.011±0.001μg in control group.3. The influence of fluorine on radio-active calcium in every mg dry tissus of calvaria of rats showed a 39370.07±198.42DPM in group 1 and it was approximately 2.62% 45CaCl2 level increase as compared with control group. In group 2, it showed a 40914.09±202.27DPM, and this was approximately 6.65% 45CaCl2 level increase as compared with a 38363.93±195.87DPM radio-active calcium of control group.4. The histological findings of the sagittal suture showed marked proliferation of osteoblasts, fibroblasts and collagen fibers in group 1 and group 2 as compared with the control group. With PAS and toluidine blue stainnigs group 1 and group 2 showed more marked positive reaction than control group. The positive reaction was noted especially around the osteoblasts and the fibroblasts and was noted diffusely in the newly formed osteoid.5. The electromicroscopic findings of the sagittal suture showed prominent proliferation of collagen fibrils and prominent bone matrix formation in group 1 and 2 as compared with control group. The findings were more prominent in group 2 than in group 1.6. According to the X-ray findings, the diameter of Haversian canals showed a tendency of narrowing in group 1 and group 2 as compared with control group. The areas between the parietal and the visceral laminae showed a remarkable tendency of increasing radio-opacity in group 1 and 2 as compared with control group and that in group 2 was more remarkable than in group 1.It is noted that the above results present increase of quantity of calcification and new bone formation on the sagittal suture according to the administration of sodium fluoride.