Experimental Animals
Online ISSN : 1881-7122
Print ISSN : 1341-1357
ISSN-L : 0007-5124
55 巻 , 4 号
選択された号の論文の11件中1~11を表示しています
Original
  • Jun IWAMOTO, Azusa SEKI, Tsuyoshi TAKEDA, Yoshihiro SATO, Harumoto YAM ...
    2006 年 55 巻 4 号 p. 333-342
    発行日: 2006年
    公開日: 2006/08/01
    ジャーナル フリー
    The purpose of the present study was to compare the therapeutic effects of risedronate (RIS) and alfacalcidol (ALF) on cancellous and cortical bone in ovariectomized osteopenic rats. Forty-two female Sprague-Dawley rats, 7 months of age, were randomized by the stratified weight method into six groups: the sham-operated control (Sham) group, and five ovariectomized groups: treated with vehicle, RIS (0.1, 1.0, or 2.5 mg/kg, p.o., daily), and ALF (0.5 μg/kg, p.o., daily). Treatment was started 6 weeks after surgery and continued for 6 weeks. Evaluation at 12 weeks after surgery revealed that ovariectomy (OVX) decreased the cancellous bone volume/total tissue volume (BV/TV) of the proximal tibial metaphysis as a result of an increase of the bone formation rate/bone surface (BFR/BS), BFR/BV, and eroded surface (ES/BS), while having no effect on the cortical area (Ct Ar) of the tibial diaphysis. OVX also decreased the maximum load of the femoral distal metaphysis, while having no effect on any mechanical property parameters of the femoral diaphysis. RIS (at all the doses) increased the BV/TV relative to the value in the OVX-Vehicle group, but the value was not restored to that observed in the Sham group. The effects of RIS (1.0 mg/kg and 2.5 mg/kg) were similar, and greater than those of RIS (0.1 mg/kg). ALF also increased the BV/TV relative to the OVX-Vehicle group, but the value was not restored to that observed in the Sham group, similar to the results of RIS (1.0 mg/kg and 2.5 mg/kg) treatment. The alterations of the structural parameters induced by RIS (at the doses) were attributable to suppression of the increase of ES/BS, BFR/BS, and BFR/BV. The alterations of the structural parameters induced by ALF were attributable to suppression of the increase of ES/BS and attenuation of the increase of BFR/BV, while the BFR/BS was maintained. ALF also increased the Ct Ar to beyond the value observed in the Sham group. RIS (at all the doses) had no effect on the mechanical properties of the femoral distal metaphysis, whereas ALF prevented the loss of the maximum load of the femoral distal metaphysis. Thus, the results of the present study show differential effects of RIS and ALF on cancellous and cortical bone in ovariectomized osteopenic rats.
  • Shin TANAKA, Sachi KUWAHARA, Kazutosi NISHIJIMA, Tamio OHNO, Akio MATS ...
    2006 年 55 巻 4 号 p. 343-347
    発行日: 2006年
    公開日: 2006/08/01
    ジャーナル フリー
    The genetic association of the agouti (a) locus with mouse adrenal X zone morphology on a specific genetic background has been suggested. To confirm this, the adrenal cortices of virgin females were compared histologically between BALB/c (A/A) and its mutant, BALB/c-a/a (a/a). The X zone was similar in the number of constituting cell layers, but different in morphology between the A/A and a/a genotypes. At 70 days of age, it was constituted of vacuolated cells exclusively in A/A and of non-vacuolated and a few vacuolated cells in a/a. At 140 days of age, the X zones contained only vacuolated cells in both genotypes. Therefore, the a (non-agouti) allele might have 2 effects upon the X zone morphology on the BALB/c background; the a allele might suppress vacuolation and delay its onset. However, the zona reticularis seemed to have no association with this locus.
  • Jun IWAMOTO, Azusa SEKI, Tsuyoshi TAKEDA, Yoshihiro SATO, Harumoto YAM ...
    2006 年 55 巻 4 号 p. 349-355
    発行日: 2006年
    公開日: 2006/08/01
    ジャーナル フリー
    We compared the effects of risedronate (Ris) and calcitriol (Cal) on cancellous osteopenia in rats treated with high-dose glucocorticoid (GC). Forty female Sprague-Dawley rats, 4 months of age, were randomized by the stratified weight method into four groups of 10 rats each according to the following treatment schedule: intact control, and GC administration with vehicle, Ris, or Cal. The GC (methylprednisolone sodium succinate, 5.0 mg/kg, s.c.), Ris (10 μg/kg, s.c.), and Cal (0.1 μg/kg, p.o.) were administered 3 times a week. At the end of the 4-week treatment period, bone histomorphometric analysis was performed for cancellous bone of the proximal tibial metaphysis. The GC administration decreased cancellous bone volume (BV/total tissue volume [TV]), trabecular number (Tb N), and trabecular thickness (Tb Th), as a result of increased bone resorption and decreased bone formation. Ris treatment markedly increased cancellous BV/TV and Tb N above the control level as a result of suppressed bone turnover. On the other hand, Cal treatment attenuated the GC-induced decrease in cancellous BV/TV and Tb Th as a result of suppressed bone resorption and maintained bone formation. This study showed the differential effects of Ris and Cal on cancellous osteopenia in rats treated with high-dose GC.
  • Jun IWAMOTO, Azusa SEKI, Tsuyoshi TAKEDA, Yoshihiro SATO, Harumoto YAM ...
    2006 年 55 巻 4 号 p. 357-367
    発行日: 2006年
    公開日: 2006/08/01
    ジャーナル フリー
    The purpose of the present study was to compare the effects of alendronate and alfacalcidol on cancellous and cortical bone mass and bone mechanical properties in ovariectomized rats. Twenty-six female Sprague-Dawley rats, 7 months of age, were randomized by the stratified weight method into four groups: the sham-operated control (Sham) group and the three ovariectomy (OVX) groups, namely, OVX + vehicle, OVX + alendronate (2.5 mg/kg, p.o., daily), and OVX + alfacalcidol (0.5 μg/kg, p.o., daily). At the end of the 8-week experimental period, bone histomorphometric analyses of cancellous bone at the proximal tibial metaphysis and cortical bone at the tibial diaphysis were performed, and the mechanical properties of the femoral distal metaphysis and femoral diaphysis were evaluated. OVX decreased cancellous bone volume per total tissue volume (BV/TV), and the maximum load of the femoral distal metaphysis, as a result of increases in serum osteocalcin (OC) levels, and also the number of osteoclasts (N.Oc), osteoclast surface (OcS) and bone formation rate (BFR) per bone surface (BS), and BFR/BV, without any effect on cortical area (Ct Ar), or maximum load of the femoral diaphysis. Alendronate prevented this decrease in cancellous BV/TV by suppressing increases in N.Oc/BS, OcS/BS, BFR/BS, and BFR/BV, without any apparent effect on Ct Ar, or maximum load of the femoral distal metaphysis and femoral diaphysis. On the other hand, alfacalcidol increased cancellous BV/TV, Ct Ar, and the maximum load of the femoral distal metaphysis and femoral diaphysis, by mildly decreasing trabecular BFR/BV, maintaining trabecular mineral apposition rate and osteoblast surface per BS, increasing periosteal and endocortical BFR/BS, and preventing an increase in endocortical eroded surface per BS. The present study clearly showed the differential skeletal effects of alendronate and alfacalcidol in ovariectomized rats. Alendronate prevented OVX-induced cancellous bone loss by suppressing bone turnover, while alfacalcidol improved cancellous and cortical bone mass and bone strength by suppressing bone resorption and maintaining or even increasing bone formation.
  • Ryo OHTA, Yukiko KANAZAWA, Tomoko SHINDO, Mami FURUYA, Mariko SHIROTA, ...
    2006 年 55 巻 4 号 p. 369-374
    発行日: 2006年
    公開日: 2006/08/01
    ジャーナル フリー
    Hatano high- and low-avoidance (HAA and LAA) rats have been genetically selected on the basis of their two-way active avoidance behavior, and have been shown to differ in other behavioral and hormonal parameters. Since close interconnections among the nervous, endocrine and immune systems have been well documented, these two strains might possess differences in aspects of immunological action. In Experiment 1, plasma levels of IgG, IgM, complement 3 (C3), classical pathway hemolytic complement (CH50) and β2-microglobulin were compared between males of the two strains at 5 and 24 weeks of age. Plasma levels of IgG and CH50 were lower in LAA than HAA rats at 5 weeks of age, whereas those differences disappeared at 24 weeks of age. There were no differences between the two strains in plasma levels of IgM, C3 and β2-microglobulin. In Experiment 2, antibody production to sheep red blood cells (SRBC) and mitogen-induced lymphocyte proliferation were compared between 12-week-old males of the two strains. Antibody responses in the PFC assay, plasma anti-SRBC-IgM levels and spleen weights were higher in LAA than HAA rats. LPS-induced lymphocyte proliferation was greater in LAA than HAA rats. It was concluded that HAA rats show earlier development of immunological development, but that antibody production and mitotic response of B lymphocytes may be more pronounced in adult LAA than HAA rats. The strain differences observed in the immunological response may indicate the usefulness of using Hatano rats in studies of behavioral-immunological relationships.
  • Kiyoshi AKEO, Tomoo FUNAYAMA, Akira OGAWA, Nobuyuki HAMADA, Yoko AKEO, ...
    2006 年 55 巻 4 号 p. 375-381
    発行日: 2006年
    公開日: 2006/08/01
    ジャーナル フリー
    Background. When dissection of porcine eyes from a living body results in the cessation of aqueous humor production and blood flow, programmed cell death regulated by TPR53BP2 and BCL2 genes may occur in the pigmented epithelium (PE) and non-pigmented epithelium (NPE) of the ciliary body. Blood products are subjected to gamma irradiation in order to prevent cellular damage resulting from transfusion-associated graft-versus-host disease.We investigated whether gamma irradiation influenced BCL2 or TPR53BP2 genes as well as the morphology of the porcine ciliary body. Methods. We irradiated the anterior segments of porcine eyes by using 60Co gamma-rays (20 Gy). To study BCL2 and TPR53BP2 expression, the irradiated specimens were fixed in formalin and embedded in paraffin and then incubated with mouse monoclonal anti-human BCL2 or TPR53BP2 antibody. Results. Following dissection, an imbalance in homeostasis began with positive BCL2 and TPR53BP2 expression in the edematous ciliary processes, and resulted in atrophy of the NPE. Increased BCL2 and TPR53BP2 expression were evident just after gamma irradiation. Decreased TPR53BP2 expression occurred after 8 h of incubation, and thereby suppressed apoptosis in the NPE; hence, the structure of the ciliary body that was incubated for 8 h after gamma irradiation was well preserved. Conclusions. Irradiation renders the ciliary body in enucleated porcine eyes less vulnerable to apoptosis, and thereby exerts a profound preservative effect.
  • Koichi NAKAZATO, Hongsun SONG, Toshiaki WAGA
    2006 年 55 巻 4 号 p. 383-389
    発行日: 2006年
    公開日: 2006/08/01
    ジャーナル フリー
    In this study, we investigated whether dietary apple polyphenol (APP) had an effect on adipose weights.Twenty-four Wistar male rats (10 weeks of age) were assigned to three groups: (1) the 5%APP group (diet containing 5% APP, N=8); (2) the 0.5%APP group (diet containing 0.5% APP, N=8); and (3) the control group (N=8) so that average weights of the groups were the same. After a three-week experimental period, adipose tissue weights were measured. Pathological and plasma characteristics were also examined. Retroperitoneal and epididymal adipose tissue weights in the 5%APP group were significantly lower than those of the control (P<0.05). Pathological examination showed that form-like cells were observed only in the control group, suggesting the existence of proliferating pre-adipocytes only in the control group. Lipid-related plasma profiles showed no statistical differences. Dietary polyphenol did not induce any anorectic effects as reported in studies concerning tea polyphenol. We conclude that dietary APP has an anti-adipogenic effect in Wistar rats without any anorectic phenomenon.
  • Masako YAJIMA, Takahiro KANNO, Takaji YAJIMA
    2006 年 55 巻 4 号 p. 391-397
    発行日: 2006年
    公開日: 2006/08/01
    ジャーナル フリー
    The object of this study was to prepare a chemically derived milk substitute that is compatible with mouse-milk. Milk was independently collected from ICR, BALB/c, and FVB/N mice, and analyzed for the protein, fat, and mineral contents to formulate a milk substitute. Thereafter, ICR mouse pups were artificially reared on the milk substitute to evaluate the rate of increase of their body weights. A gastric cannula tube was placed through the esophageal way into 8-day-old ICR pups, and the mice were fed with the milk substitute by computer-regulated infusion pumping by the pup-in-a-cup method. The analytical mean values of total protein and total fat in milk from ICR, BALB/c, and FVB/N mice were 10.23 ± 0.49% and 21.34 ± 1.31%, respectively. The milk substitute was constituted from purified bovine casein and whey proteins, five edible oils, including MCT oil, minerals, and vitamins. After 8 days of artificial rearing with the new milk substitute, 36 of the 42 pups had survived, and the growth rate of these mice was not significantly different from that of maternally reared littermate pups. In conclusion, we have succeeded in the preparation of a chemically derived milk substitute for mice pups which is available for clarifying the roles of dietary components such as milk-bone substance during the suckling period in mice pups including those of knockout and transgenic mice.
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