Biomedical subjects

Tsuyoshi Takeda

Publications and source records attributed to Tsuyoshi Takeda.

At least 37 records · Page 2Linked to original sources

PubMed2005

Effect of treadmill exercise on bone mass in female rats.

Increasing peak bone mass at skeletal maturity, minimizing bone loss during middle age and after menopause, and increasing bone mass and preventing falls in advanced age are important measures for preventing osteoporotic fractures in women. Exercise has generally been considered to have a positive influence on bone health. This paper reviews the effects of treadmill exercise on bone in young, adult, ovariectomized, and osteopenic female rats. Treadmill exercise increases cortical and cancellous bone mass of the tibia as a result of increased bone formation and decreased bone resorption in young and adult rats. The increase in lumbar bone mass seems to be more significant when long-term exercise is applied. Treadmill exercise prevents cancellous bone loss at the tibia as a result of suppressed bone resorption in ovariectomized rats, and increases bone mass of the tibia and mechanical strength of the femur, as a result of suppressed bone resorption and increased bone formation in osteopenic rats after ovariectomy. Treadmill exercise transiently decreases the serum calcium level as a result of accumulation of calcium in bone, resulting in an increase in serum 1,25-dihydroxyvitamin D(3) level and a decrease in serum parathyroid hormone level. We conclude that treadmill exercise may be useful to increase bone mass in young and adult rats, prevent bone loss in ovariectomized rats, and increase bone mass and bone strength in osteopenic rats, especially in the long bones at weight-bearing sites. Treadmill exercise may have a positive effect on the skeleton in young, and adult, ovariectomized, and osteopenic female rats.

Animals↗

PubMed2005

Interventions to prevent bone loss in astronauts during space flight.

This paper reviews the interventions to stabilize calcium balance and bone metabolism and prevent bone loss in astronauts during space flight. Weightlessness during space flight results in calcium, vitamin D, and vitamin K deficiency, increases urinary calcium excretion, decreases intestinal calcium absorption, and increases serum calcium level, with decreased levels of serum parathyroid hormone and calcitriol. Bone resorption is increased, whereas bone formation is decreased. The loss of bone mineral density (BMD) in the spine, femoral neck and trochanter, and pelvis is 1.0-1.6% per month. High calcium intake and vitamin D supplementation during space flight does not affect bone metabolism, but prevents an elevation of serum calcium level through increased calcitriol level, while vitamin K counteracts the reduction in bone formation. However, there are no data to show the efficacy of pharmaceutical agents for prevention of development of osteoporosis in astronauts during flight, although the preventative effect of bisphosphonates, testosterone, and vitamin K2 on cancellous bone loss in the tibia or BMD loss in the hindlimb was reported in tail-suspended mature rats. It still remains uncertain whether these agents can prevent cortical bone loss caused by weightlessness in tail-suspended rats. Therefore, in addition to calcium, vitamin D, and vitamin K supplementation, agents that have both potent anti-resorptive and anabolic effects on cancellous and cortical bone may be needed to stabilize calcium balance and bone metabolism and prevent bone loss in astronauts during space flight.

Aerospace Medicine↗

PubMed2005

Comparative effects of vitamin K and vitamin D supplementation on calcium balance in young rats fed normal or low calcium diets.

We examined the effect of vitamin K and vitamin D supplementation on calcium balance in young rats fed a normal or low calcium diet. Eighty female Sprague-Dawley rats, 6 wk of age, were randomized by the stratified weight method into eight groups with 10 rats in each group: 0.5% (normal) or 0.1% (low) calcium diet, 0.5% or 0.1% calcium diet+vitamin K (vitamin K2, menatetrenone, 30 mg/100 g, food intake), 0.5% or 0.1% calcium diet+vitamin D (25 microg/100 g, food intake), and 0.5% or 0.1% calcium diet+vitamin K+vitamin D. The duration of the study was 10 wk. Vitamin K supplementation promoted the reduction in urinary calcium excretion and retarded the abnormal elevation of serum PTH level in rats fed a low calcium diet, and stimulated intestinal calcium absorption in rats fed a normal calcium diet. Vitamin D supplementation stimulated intestinal calcium absorption with prevention of the abnormal elevation of serum PTH levels and prevented hypocalcemia in rats fed a low calcium diet, and stimulated intestinal calcium absorption in rats fed a normal calcium diet. The stimulation of intestinal calcium absorption was associated with increased serum 1,25-dihydroxyvitamin D levels. An additive effect of vitamin K and vitamin D on intestinal calcium absorption was found only in rats fed a normal calcium diet. This study shows the differential effects of vitamin K and vitamin D supplementation on calcium balance in young rats fed a normal or low calcium diet.

Animals↗

PubMed2004

Determinants of one-year response of lumbar bone mineral density to alendronate treatment in elderly Japanese women with osteoporosis.

The purpose of this study was to determine factors that could predict the one-year response of the lumbar bone mineral density (BMD) to alendronate treatment in elderly Japanese women with osteoporosis. Eighty-five postmenopausal women with osteoporosis, all of whom were between 55-88 years of age, were treated with alendronate (5 mg daily) for 12 months. Serum calcium, phosphorus, and alkaline phosphatase (ALP) and urinary NTX levels were measured at the baseline and 6 months, and lumbar (L1-L4) BMD was measured by dual energy X-ray absorptiometry at the baseline and 12 months. Multiple regression analysis was used to determine factors that were correlated with the percent change in lumbar BMD at 12 months. Lumbar BMD increased by 8.1 % at 12 months with a reduction in the urinary NTX level by 51.0 % at 6 months. Baseline lumbar BMD (R2=0.226, p < 0.0001) and percent changes in serum ALP and urinary NTX levels (R2=0.044, p < 0.05 and R2=0.103, p < 0.001, respectively) had a negative correlation with the percent change in lumbar BMD at month 12, while the baseline number of prevalent vertebral fractures (R2=0.163, p < 0.001), serum ALP level, and urinary NTX level (R2=0.074, p < 0.05 and R2=0.160, p < 0.001, respectively) had a positive correlation with it. However, baseline age, height, body weight, body mass index, years since menopause, serum calcium and phosphorus levels, and percent changes in serum calcium and phosphorus levels at 6 months did not have any significant correlation with the percent change in lumbar BMD at 12 months. These results suggest that lumbar BMD was more responsive to one-year of alendronate treatment in elderly osteoporotic Japanese women with lower lumbar BMD, more prevalent vertebral fractures, and higher bone turnover, who showed a greater decrease in bone turnover at 6 months, regardless of age, years since menopause, and physique. Alendronate may be efficacious in elderly Japanese women with evident osteoporosis that is associated with high bone turnover, and the percent changes in serum ALP and urinary NTX levels at 6 months could predict the one-year response of lumbar BMD to alendronate treatment.

Absorptiometry, Photon↗

PubMed2004

Effects of alendronate on metacarpal and lumbar bone mineral density, bone resorption, and chronic back pain in postmenopausal women with osteoporosis.

The purpose of this study was to investigate the effect of alendronate on metacarpal and lumbar bone mineral density (BMD), bone resorption, and chronic back pain in postmenopausal women with osteoporosis. Eighty postmenopausal women with osteoporosis, 59-88 years of age, were divided into two groups of 40 each according to the site of BMD measurement: the metacarpus (M) and the lumbar spine (L). All of them were treated with alendronate (5 mg/day) for 12 months. Metacarpal or lumbar BMD was measured by computed X-ray densitometry or dual-energy X-ray absorptiometry in the M or the L group, respectively, at baseline and every 6 months. Urinary cross-linked N-terminal telopeptides of type I collagen (NTX) were measured by enzyme-linked immunosorbent assay, and chronic back pain was evaluated by face scale score at baseline and every 6 months in both groups. There were no significant differences in baseline characteristics, including age, body mass index, years since menopause, urinary NTX level, face scale score, or number of prevalent vertebral fractures per patient between the two groups. Urinary NTX level was reduced and chronic back pain was improved similarly in both groups. Whereas metacarpal BMD did not significantly change in the M group (0.20% increase), lumbar BMD increased by 8.15% in the L group. These results suggest that although alendronate increases BMD of the lumbar spine, which is rich in cancellous bone, and improves chronic back pain, with suppression of bone resorption in postmenopausal women with osteoporosis, it may fail to increase cortical BMD of the metacarpus, a distal site of the upper extremity.

Absorptiometry, Photon↗

PubMed2004

Differential effect of vitamin K and vitamin D supplementation on bone mass in young rats fed normal or low calcium diet.

The purpose of this study was to clarify the differential effect of vitamin K and vitamin D supplementation on bone mass in young rats fed a normal or low calcium diet. Ninety female Sprague-Dawley rats, 6 weeks of age, were randomized by stratified weight method into nine groups with 10 rats in each group: baseline control, and 0.5% (normal) or 0.1% (low) calcium diet, either alone, or with vitamin K (30 mg/100g, food intake), vitamin D (25 micro g/100 g, food intake), or vitamin K + vitamin D. After 10 weeks of feeding, bone histomorphometric analyses were performed on cortical bone of the tibial shaft and cancellous bone of the proximal tibia. Vitamin K supplementation increased the maturation-related cancellous bone gain and retarded the reduction in the maturation-related cortical bone gain in rats fed a low calcium diet, and increased the maturation-related cortical bone gain in rats fed a normal calcium diet. Vitamin D supplementation reduced the maturation-related cancellous bone gain, prevented the reduction in periosteal bone gain, and enhanced the enlargement of the marrow cavity, with no significant effect on the reduction in the maturation-related cortical bone gain in rats fed a low calcium diet, and increased the maturation- related cancellous and cortical bone gains with increased periosteal bone gain in rats fed a normal calcium diet. An additive effect of vitamin K and vitamin D on the maturation- related cortical bone gain was found in rats fed a normal calcium diet. This study shows the differential effects of vitamin K and vitamin D supplementation on cancellous and cortical bone mass in young rats fed a normal or low calcium diet, as well as the additive effect on cortical bone under calcium sufficient condition.

Age Factors↗

PubMed2004

Effects of treadmill exercise on bone mass, bone metabolism, and calciotropic hormones in young growing rats.

The aim of the present study was to examine the effects of exercise on bone mass, bone metabolism, and calciotropic hormones in young growing rats. Twenty 6-week-old female Wistar rats were randomized into the following four groups with 5 animals each: 7 weeks of exercise, 7 weeks of sedentary control, 11 weeks of exercise, and 11 weeks of sedentary control. The exercise regimen consisted of running on a treadmill at 25 m/min for 1 h each day on 5 days a week. After each period of exercise, the bone mineral content (BMC) of the tibia and fifth lumbar spine was measured by dual-energy X-ray absorptiometry, using a Lunar DPX-L instrument. The femoral length and levels of bone markers and calciotropic hormones were also assessed. Seven and 11 weeks of exercise increased the serum osteocalcin and 1,25-dihydroxyvitamin D(3) levels, and decreased the serum parathyroid level. Seven weeks of exercise decreased the urinary deoxypyridinoline level, and 11 weeks of exercise increased the serum alkaline phosphatase level and decreased the serum tartrate-resistant acid phosphatase level. As a result, 7 and 11 weeks of exercise increased the femoral length and tibial BMC, but did not alter the lumbar BMC. The present study demonstrates that treadmill exercise stimulates bone formation and suppresses bone resorption, increases the serum 1,25-dihydroxyvitamin D(3) level, and decreases the serum parathyroid hormone level, resulting in an increase in bone mass with stimulation of longitudinal bone growth, especially at weight-bearing sites, in young growing rats. Further studies with long-term exercise may be needed to obtain a positive effect on the lumbar BMC.

Absorptiometry, Photon↗

PubMed2004

Effect of walking exercise on bone metabolism in postmenopausal women with osteopenia/osteoporosis.

The purpose of this prospective study was to determine whether moderate walking exercise in postmenopausal women with osteopenia/osteoporosis would affect bone metabolism. Fifty postmenopausal women, aged 49-75 years, with osteopenia/osteoporosis were recruited: 32 women entered the exercise program (the exercise group) and 18 served as controls (the control group). The exercise consisted of daily outdoor walking, the intensity of which was 50% of maximum oxygen consumption, with a duration of at least 1 h with more than 8000 steps, at a frequency of 4 days a week, over a 12-month period. Lumbar (L2-L4) bone mineral density (BMD) was measured at the baseline and every 6 months with dual-energy X-ray absorptiometry (DXA) in both groups. Serum bone-specific alkaline phosphatase (BAP) and urinary cross-linked N-terminal telopeptides of type I collagen (NTX) levels were measured at baseline and at months 1, 3, 6, 9, and 12 by EIA and ELISA, respectively, in the exercise group, and urinary NTX level was measured at the baseline and every 6 months in the control group. There were no significant differences in baseline characteristics including age, height, body weight, bone mass index, years since menopause, lumbar BMD, and urinary NTX level between the two groups. Although no significant changes were observed in lumbar BMD and the urinary NTX level in the control group, lumbar BMD in the exercise group was increased as compared with the control group, but was sustained from the baseline. In the exercise group, the urinary NTX level rapidly responded to walking exercise from month 3, and this reduction was sustained until month 12, followed by reduction in the serum BAP level. A moderately negative correlation was found between the percent change in the urinary NTX level at month 3 and that in lumbar BMD at month 12 in the exercise group. This study clearly demonstrates that the mechanism for the positive response of lumbar BMD to moderate walking exercise in postmenopausal women with osteopenia/osteoporosis appears to be the suppression of bone turnover, and that an early change in the urinary NTX level may be useful to predict the long-term response of increasing lumbar BMD to exercise, although its efficacy for lumbar BMD may be quite modest.

Aged↗

PubMed2004

Rheumatoid factors induce signaling from B cells, leading to Epstein-Barr virus and B-cell activation.

B-cell antigen receptor signaling is initiated upon binding of the antigen to membrane-bound immunoblobulin (Ig), and the anti-Ig antibody (Ab) mimics this signaling. In B cells latently infected with Epstein-Barr virus (EBV), the same signals induce virus activation. We examine here whether rheumatoid factors (RFs), autoantibodies directed against the Fc portion of IgG, induce EBV and B-cell activation. As a source of RFs, RF-producing lymphoblastoid cell line (LCL) clones were isolated from peripheral blood mononuclear cells (PBMC) and synovial cells from patients with rheumatoid arthritis (RA) by EBV transformation. Burkitt's lymphoma-derived Akata cells, which are highly responsive to EBV activation by anti-Ig Abs, were used for the assay of EBV activation. Akata cells expressed IgG3 as membrane-bound Ig. RFs from a synovium-derived LCL were directed to IgG3 and induced EBV activation in 16 to 18% of Akata cells, whereas RFs from another synovium-derived LCL were directed to IgG1 and did not induce EBV activation. Pretreatment of RFs with the purified Fc fragment of human IgG completely abolished EBV activation. Furthermore, B-cell activation was assessed by incorporation of [3H]thymidine. RFs from synovium-derived LCLs efficiently induced B-cell activation, and the addition of CD40 ligand had a synergistic effect. On the other hand, RFs from PBMC-derived LCLs were polyreactive, had a lower affinity to IgG, and did not induce EBV and B-cell activation. The present findings imply a possible role for RFs as EBV and B-cell activators.

Arthritis, Rheumatoid↗

PubMed2004

Response of cortical and cancellous bones to mild calcium deficiency in young growing female rats: a bone histomorphometry study.

The purpose of the present study was to clarify the differences in the alterations of cellular activities of osteoblasts and osteoclasts, mineralization, and bone mass in cortical and cancellous bones of young growing rats with mild calcium deficiency. Twenty female Sprague-Dawley rats, 6 weeks of age, were randomized by the stratified method into two groups with 10 rats in each group: 0.5% (normal) calcium diet group and 0.1% (low) calcium diet group. After 10 weeks of feeding, bone histomorphometric analysis was performed on cancellous bone of the proximal tibia as well as cortical bone of the tibial shaft. Calcium deficiency increased eroded surface (ES/bone surface [BS]) and the number of osteoclast (N.Oc/BS) with an increase in osteoblast surface (ObS/BS), but decreased bone formation rate (BFR/BS) in cancellous bone. However, cancellous bone volume was preserved, while cortical bone area was decreased as a result of decreased periosteal bone gain and enlargement of the marrow cavity. These results suggest that short-term mild calcium deficiency in young growing female rats increased bone resorption by increasing osteoclastic recruitment, and suppressed mineralization followed by increased osteoblastic recruitment in cancellous bone, but cancellous bone loss was counteracted through redistribution of calcium from cortical bone to cancellous bone.

Animals↗

PubMed2004

Retracted: Effects of Vitamin K2 on Osteoporosis

The article entitled “Effects of Vitamin K2 on Osteoporosis, published in Curr Pharm Des 2004; 10(21): 2557-76, by Iwamoto J, Takeda T and Sato Y.” has been retracted by the Editorial office of the journal Current Pharmaceutical Design, as the text, data and some figures used/referred in this review article are from sources which have been retracted or under investigation on the basis of data fabrication and falsification, authorship misconduct, duplicate publication, unethical research practices, text recycling/self-plagiarism, and unresolved concerns about data integrity and research conduct. The authors were informed of this complaint and were requested to give justification on the matter in their defense. However, no reply was received from their side in this regard. Some sources that have been retracted are as follows: REFERENCE: 1. Iwamoto J, Takeda T, Ichimura S. Combined treatment with vitamin K2 and bisphosphonate in postmenopausal women with osteoporosis. Yonsei Med J 2003; 44: 751-6. Available at: https://eymj.org/DOIx.php?id=10.3349/ymj.2019.60.1.115. 2. Sato Y, Honda Y, Kuno H, Oizumi K. Menatetrenone ameliorates osteopenia in disuse-affected limbs of vitamin D- and K-deficient stroke patients. Bone 1998; 23: 291-6. Available at: https://www.sciencedirect.com/science/article/pii/S8756328298001082. 3. Sato Y, Honda Y, Kaji M, Asoh T, Hosokawa K, Kondo I, et al. Amelioration of osteoporosis by menatetrenone in elderly female Parkinson's disease patients with vitamin D deficiency. Bone 2002; 31: 114-8. Available at: https://pubmed.ncbi.nlm.nih.gov/ 12110423/. Bentham Science apologizes to its readers for any inconvenience this may have caused. The Bentham Editorial Policy on Article. Retraction can be found at https://benthamscience.com/editorial-policies-main.php BENTHAM SCIENCE DISCLAIMER: It is a condition of publication that manuscripts submitted to this journal have not been published and will not be simultaneously submitted or published elsewhere. Furthermore, any data, illustration, structure or table that has been published elsewhere must be reported, and copyright permission for reproduction must be obtained. Plagiarism is strictly forbidden, and by submitting the article for publication the authors agree that the publishers have the legal right to take appropriate action against the authors, if plagiarism or fabricated information is discovered. By submitting a manuscript, the authors agree that the copyright of their article is transferred to the publishers if and when the article is accepted for publication.

Animals↗

PubMed2004

Differential effect of short-term etidronate treatment on three cancellous bone sites in orchidectomized adult rats.

The aim of the present study was to analyze the effects of short-term treatment with the antiresorptive agent, etidronate, on orchidectomized adult rats, via comparison of three cancellous bone sites, the lumbar vertebral body (LVB), proximal tibial metaphysis (PTM), and distal tibial metaphysis (DTM). Thirty-five male Wistar rats, aged 10 months, were randomly divided into four groups: baseline control (BLC, nF10), age-matched sham-operated control (AMC, nF9), orchidectomy (ORX, nF9), and ORXBetidronate treatment (nF7). Etidronate treatment (10 mg/kg, daily subcutaneous injection) was initiated 2 weeks after surgery and was continued for 2 weeks. Four weeks after surgery, the 5th LVB, PTM, and DTM were processed for histomorphometric analysis of cancellous bone (secondary spongiosa). ORX resulted in a decrease in body weight. No significant difference in cancellous bone volume (BV/TV) was found between the BLC and AMC groups at any skeletal site. The cancellous BV/TV loss was attributable to increased eroded surface (ES/BS) with no significant alteration in the mineral apposition rate (MAR), at all skeletal sites and etidronate treatment in ORX rats significantly decreased ES/BS to a level not significantly different from that in the AMC group, resulting in complete prevention of ORX-induced cancellous BV/TV loss. The MAR was markedly decreased in the PTM and LVB, but maintained in the DTM by etidronate treatment. The present study showed that etidronate treatment could completely prevent ORX-induced cancellous bone loss regardless skeletal sites by suppressing bone resorption. In particular, suppression of bone formation in terms of osteoblastic activity by etidronate treatment was not evident only in the DTM

Animals↗

PubMed2004

Effect of treatment with alendronate in osteogenesis imperfecta type I: a case report.

A case of osteogenesis imperfecta (OI), which was successfully treated with alendronate is reported. A 41-year-old premenopausal woman with OI type I, who had frequently been experiencing fragile fractures, consulted our clinic because of back pain associated with spinal osteoporosis. She had experienced heart surgery (aortic valve replacement) due to aortic regurgitation 5 years before her first consultation with our clinic. After the surgery, she had been taking warfarin 3 mg/day, and this treatment was continued during our follow-up period. She was treated with alendronate (5 mg/day, daily) for 18 months. The bone mineral density of the lumbar spine (L2-L4) measured by dual energy X-ray absorptiometry (Norland XR-36) increased for 18 months, and back pain markedly decreased. The urinary cross-linked N-terminal telopeptides of type I collagen and serum bone-specific alkaline phosphatase, osteocalcin, and undercarboxylated osteocalcin levels also markedly decreased. No new fragile vertebral or non-vertebral fractures were observed during the 18 months of treatment. This report provides evidence indicating that treatment with oral alendronate may have the potential to decrease bone turnover, improve the lumbar BMD, reduce back pain, and prevent new fragile fractures in premenopausal women with OI type I.

Adult↗

PubMed2004

Efficacy of training program for ambulatory competence in elderly women.

The optimal prevention of osteoporotic fractures in the elderly consists of increasing the bone density and preventing falls. We report on the efficacy of training program to promote ambulatory competence in elderly women. Twenty-five elderly women were enrolled in our training program, which is a three-month program consisting of dynamic balance training with Galileo 900 (Novotec, Pforzheim, Germany) once a week, combined with daily static balance (standing on one leg like a flamingo) and resistance (half-squat) training. The mean age of the participants was 72.8 years (range, 61-86 years). After 3 months of training, the step length, knee extensor muscle strength, and maximum standing time on one leg were significantly increased, while the walking speed and hip flexor muscle strength were not significantly altered. During the study period, no serious adverse events such as new vertebral fractures or adverse cardiovascular symptoms were observed in any participant. The present preliminary study shows that our training program may have the potential to promote ambulatory competence in elderly women.

Age Factors↗

PubMed2003

Combined treatment with vitamin k2 and bisphosphonate in postmenopausal women with osteoporosis.

Vitamin K2, as well as bisphosphonates, such as etidronate, alendronate, and risedronate, is widely used in the treatment with osteoporosis in Japan. Etidronate increases the lumbar bone mineral density (BMD), and prevents new vertebral fractures, in patients with osteoporosis, while alendronate and risedronate increase the lumbar and femoral neck BMDs, and prevent new vertebral and femoral neck fractures. Vitamin K2 enhances gamma-carboxylation of bone glutamic acid residues and the secretion of osteocalcin, sustains the lumbar BMD, and prevents osteoporotic fractures in patients with osteoporosis. Bisphosphonates, such as alendronate and risedronate, rather than vitamin K2, should be initially chosen for the treatment of osteoporosis, because they are more efficacious than vitamin K2. Available evidence suggest that risedronate prevents deterioration of the connectivity of the trabeculae in ovariectomized rats, whereas vitamin K2 increase the trabecular thickness, and that a combination of risedronate and vitamin K2 has a synergistic effect on preventing the deterioration of trabecular bone architecture induced by estrogen deficiency. Some studies have shown that combined treatment with etidronate and vitamin K2 appears to be more effective than etidronate alone in the prevention of new osteoporotic vertebral fractures. Based on these findings, combined treatment with vitamin K2 and bisphosphonates may be more efficacious in the prevention new vertebral fractures than a single treatment with bisphosphonate in postmenopausal women with osteoporosis. Thus, this combined treatment should be recommended for the treatment of postmenopausal osteoporosis. It is proposed that the role of vitamin K2 should be emphasized, when used in combination with bisphosphonates, especially in patients with vitamin K deficiency.

Aged↗

PubMed2003

Protective effects of glutathione on 5-fluorouracil-induced myelosuppression in mice.

The protective effects of glutathione (GSH) administration on myelosuppression induced by 5-fluorouracil (5-FU) were investigated in female BALB/c mice. Animals were allocated to four groups (16 mice/group). GSH was given orally at a dose of 800 mg/kg to groups 3 and 4 for 21 consecutive days (day 0 to day 20). 5-FU was repeatedly administered at a dose of 40 mg/kg to groups 2 and 3 for 1 week (day 7 to day 13) by gavage. Group 3 served as a combined treatment group and group 1 as a non-treated control group. The total observation period was 3 weeks. Body weight was measured once a week. A decrease in body weight due to 5-FU treatment was observed in groups 2 and 3 on day 14. Although the body weight in group 2 had not increased by 1-week after cessation of 5-FU treatment, the value in group 3 markedly recovered. Hematology, total nucleated myelocyte count and histopathology of bone marrow were carried out on day 14 and day 21. In groups 2 and 3, these examinations showed thrombocytopenia, leukopenia, reticulocytopenia and myelosuppression on day 14. However, platelets and bone marrow were less affected in group 3 than in group 2. On day 21, the thrombocytopenia in groups 2 and 3 was resolved. The myelosuppression, leukopenia and reticulocytopenia resolved in group 3, but not in group 2. Although simple microcytic anemia occurred delayed on day 21, it was less severe in group 3 than in group 2. Therefore, GSH may have preventive effects against 5-FU-induced hematopoietic toxicity, and accelerate recovery after cessation of 5-FU treatment.

Administration, Oral↗

PubMed2003

Effect of vitamin K2 on cortical and cancellous bones in orchidectomized young rats.

OBJECTIVES: The purpose of the present study was to compare the effect of vitamin K(2) on cortical and cancellous bones in orchidectomized young rats. METHODS: Forty male Sprague-Dawley rats, 6 weeks of age, were randomized by stratified weight method into four groups with 10 rats in each group: baseline controls (BLC), age-matched controls (AMC), orchidectomy (ORX), and ORX+vitamin K(2) administration (K). Vitamin K(2) (menatetrenone) was administered subcutaneously twice a week at dose of 30 mg/kg each. The experimental period was 8 weeks, and cortical and cancellous bone histomorphometry was performed on the tibial shaft and the proximal tibia, respectively. RESULTS: Cortical area (Ct Ar) and cancellous bone volume (BV/TV) were significantly greater in the AMC group than in the BLC group. Ct Ar was significantly lower in the ORX group than in the AMC group, and cancellous BV/TV was also significantly lower in the ORX group than in the AMC group as a result of significantly increased eroded surface (ES/BS). Although Ct Ar in the ORX+K group did not differ significantly from that in the ORX group, cancellous BV/TV was significantly greater in the ORX+K group than in the ORX group, but still significantly lower than in the AMC group. This protective effect of vitamin K(2) on cancellous bone was attributable to normalizing increased ES/BS. CONCLUSIONS: Vitamin K(2) appears to act more strongly on cancellous bone than on cortical bone in ORX young rats. High dose vitamin K(2) could partially prevent the reduction of cancellous bone gain by normalizing raised bone resorption in ORX young rats.

Animals↗

PubMed2003

Comparative effects of orchidectomy and sciatic neurectomy on cortical and cancellous bone in young growing rats.

The purpose of the present study was to compare the effects of orchidectomy and sciatic neurectomy on cortical and cancellous bone in male rats. Fifty male Sprague-Dawley rats, 6 weeks of age, were randomized into five groups, with ten rats in each group: baseline control, age-matched intact control, orchidectomy (ORX), unilateral sciatic neurectomy (NX), and ORX + NX. After 8 weeks of feeding, the tibial shaft and proximal tibia were processed for cortical and cancellous bone histomorphometric analyses, respectively. ORX-induced reductions in maturation-related cortical and cancellous bone gains were attributable to decreased periosteal bone gain and increased trabecular bone resorption, respectively. NX- and ORX + NX-induced reductions in maturation-related cortical bone gain were attributable to decreased periosteal bone formation and increased endocortical bone turnover, while NX- and ORX + NX -induced reductions in maturation-related cancellous bone gain were attributable to increased bone resorption and decreased bone formation. NX more markedly reduced maturation-related cortical and cancellous bone gains than did ORX, and the ORX-induced reductions in maturation-related cortical and cancellous bone gains were more pronounced when combined with NX. The present study demonstrated differences in changes in cortical and cancellous bone following ORX and NX in young rats. The importance of mechanical loading, with or without testosterone deficiency, is emphasized in cortical and cancellous bone growth.

Animals↗