Alendronate (alendronate sodium hydrate; Bonalon Tablet, 5 mg) is a nitrogen-containing bisphosphonate, which combines with the bone surface and reduces osteoclast-mediated bone resorption. It is a third-generation bisphosphonate compound, specifically distributed on the surface of bone resorption and taken into osteoclasts. Under the closed circumstances which is formed with osteoclast and the bone surface, alendronate becomes detached from the bone surface and taken into osteoclast since acid released from osteoclast leads to pH decrease (acidified). The uptaken alendronate blocks the pathway of mevalonic acid synthesis, which is cholesteric synthesis, inhibits the prenylation of GTP binding protein, and decreases the osteoclast's function by influencing the cytoskeleton. This restraint of alendronate in bone resorption against osteoclasts is reversible, showing no cytotoxicity at more than hundredfold concentration level at which action occurs. Alendronate is an agent for the treatment of osteoporosis that has established safety with regards to bone quality since it neither inhibits bone calcification nor influences fracture healing in chronic administration. The most serious morbidity in osteoporosis is developing fractures. The efficacy of alendronate on restraining fracture, as well as on increase in BMD, is evidenced in Japan. Recently, in addition to senile or postmenopausal osteoporosis, drug-induced osteoporosis, such as steroid-induced osteoporosis, has attracted attention. In this regard, alendronate has been found to be an effective agent for the treatment of osteoporosis overseas, being approved in over 90 countries and used by more than 4.5 million patients. This review will give an outline of alendronate, the preparation to have introduced a concept of Evidence Based Medicine earlier, from pharmacodynamic action to clinical efficacy.

Endothelial cells (ECs) are believed to be critical cellular elements responsible for postnatal angiogenesis. Vascular endothelial growth factor (VEGF) stimulates angiogenesis via the activation of KDR/Flk-1 receptor, which is mainly expressed in ECs. Transactivation of KDR/Flk-1 receptor by bradykinin (BK) B2 receptor contributes to the activation of endothelial nitric-oxide (NO) synthase. Therefore, we examined whether transactivation by BK induced angiogenesis.

Chronic mild or moderate stress elicits an adaptive change in central nervous systems that function to maintain homeostasis. The principal components of stress response are the extrahypothalamic corticotropin-releasing hormone (CRH) and the locus coeruleus (LC)-norepinephrine (NE) systems. CRH is known to produce various stress-, anxiety- and arousal-associated behaviors in animals. Moreover, CRH causes an increase in the firing rate and activity of tyrosine hydroxylase in the LC, and NE release in LC projection areas. It is thought that chronic inescapable and unpredictable stress can result in a sustained dysregulation of both CRH neuronal activity and LC-NE systems. One may hypothesize that the NE-CRH interaction occurs in the terminal projection of forebrain NE systems, the hypothalamic paraventricular nucleus (PVN), the bed nucleus of the stria terminalis (BNST) and the central nucleus of the amygdala (CeA) where NE stimulates CRH release. Such CRH-NE-CRH feed-forward systems elicit progressive augmentation of stress responsivity with repeated exposure. The beta-adrenergic receptor down-regulation is induced by acute and chronic exposure to moderate and predictable stress, implying an adaptation to stress. However, chronic unpredictable (variable) stress (CVS), a model for depression, up-regulated the beta-AR. In our laboratory, we found that concurrent treatment with the selective serotonin reuptake inhibitor (SSRI) citalopram caused beta-R down-regulation in the frontal cortex of rats treated with CVS for 14 days. As previously reported by the authors, an increase in 5-HT availability plays a role in preserving beta-R down-regulation by NE potentiating agents. In depressed patients, hyperactivation of the CRH-NE systems caused by the CRH-NE feed-forward system is thought to be involved in generating anxiety, sympathetic activation and hyperarousal. Moreover, a decrease in the 5-HT turnover in depressed patients has been reported. Accordingly, it is proposed that an increase in 5-HT availability by SSRI might contribute to normalize beta-R down-regulation as an adaptive regulatory mechanism against excessive CRH-NE neurotransmission under a "stressful" situation.

We examined the role of protein kinase C (PKC) in the phosphorylation of a p53 protein. Exposure to a protein kinase inhibitor, 1-(5-isoquinolinesulfonyl)-2-methylpiperazine dihydrochloride (H7), increased the phosphorylation of the wild type p53 protein, whereas exposure to a tumor promoter phorbol ester, 12-O-tetradecanoyl-phorbol-13-acetate (TPA), decreased it in vivo after incubation with mouse epidermal JB6 cells for 3 h. Exposure to a cAMP dependent protein kinase (PKA) activator, forskolin, did not decrease the phosphorylation of p53 protein. In the transient transfection/luciferase reporter transactivation assay, H7 slightly increased the mouse double minute (MDM) 2 reporter transactivation activity of the p53 protein after treatment for 24 h, whereas TPA completely blocked it. Exposure to H7 and a specific PKC inhibitor, bisindolylmaleimide (bis), dose-dependently reduced the lung-colonizing potential of highly metastatic B16-F10 mouse melanoma cells in syngeneic mice. These results suggest that the phosphorylation of the wild type p53 protein is inversely related to PKC activation, and also suggest that the phosphorylation of the p53 protein is involved in the function of its transcription factor. The PKC inhibitor may exhibit a potent anti-metastatic effect through the phosphorylation of wild type p53 protein and the activation of its function.

Cytochrome P450(CYP) comprises a large superfamily of hemoproteins that plays a vital role in the biotransformation of variety of xenobiotics as well as endobiotics. CYPs 1-4 metabolize foreign compounds such as drugs, environmental pollutants and carcinogens influencing drug-drug interactions, drug or carcinogen activation and detoxification, and in addition, xenobiotics induce CYP genes. CYPs 1-4 also metabolize endogenous compounds, including steroid hormones, retinoid, bile acids, prostagrandins, and thus have roles in not only elimination but also production of endobiotic signaling molecules. Some of the orphan receptors may function as the receptors of these signaling molecules.

The aryl hydrocarbon receptor(AhR) plays a central role in the metabolic pathways involved in the detoxification of important environmental carcinogens, most of which act as ligand for the receptor, although no endogeneous ligand has not yet been known. Activation of the AhR is responsible for a variety of toxic responses in animals and humans. The activation mechanisms become clear that include binding of ligand to receptor, transfer to the nucleus, formation of a ternary complex with Arnt, followed by binding to response elements upstream of the relevant target genes. However, the specific mechanisms responsible for the toxic responses of dioxins are unknown.

Effects of auranofin, an orally active chrysotherapeutic agent, were examined on the production of prostaglandin E2 (PGE2) and nitric oxide (NO) in rat peritoneal macrophages and in RAW 264.7 cells, a murine macrophage-like cell line. Auranofin (1-10 microM) inhibited PGE2 production in rat peritoneal macrophages stimulated with 12-O-tetra-decanoylphorbol 13-acetate (TPA, 16.2 nM) at 8-20 h, but did not affect PGE2 production at 4 h. However, in non-stimulated rat peritoneal macrophages, auranofin increased PGE2 production at 4 h and had no effect on PGE2 production at 8-20 h. It was proved that auranofin (1-10 microM) increased COX (cyclooxygenase)-1-dependent PGE2 production and inhibited COX-2-dependent PGE2 production in rat peritoneal macrophages. Auranofin showed no effect on the enzyme activities of the purified COX-1 and COX-2 proteins. Furthermore, auranofin did not affect the COX-1 protein level, but inhibited the TPA-induced expression of COX-2 protein. Therefore, it was suggested that auranofin inhibited PGE2 production by inhibiting the COX-2 protein induction in TPA-stimulated macrophages. In RAW 264.7 cells, auranofin (0.3-3 microM) inhibited lipopolysaccharide-induced NO synthesis by inhibiting the induction of NO synthase (NOS) protein expression. Auranofin did not affect the enzyme activity of iNOS (inducible NOS). Finally, using rat peritoneal macrophages, the effects of auranofin on PGE2 production and NO production were determined. Auranofin (10 microM) strongly inhibited the production of PGE2 and NO, and the induction of COX-2 protein and NOS protein by TPA. Indomethacin, a COX inhibitor, partially inhibited NO production at the concentration at which PGE2 production was completely inhibited. On the other hand, L-NG-monomethyl-L-arginine acetate (L-NMMA), a NOS inhibitor, partially inhibited PGE2 production. NO production was completely inhibited at the same concentration as shown above. These findings suggest that PGE2 production and NO production partially affect each other. Therefore, the inhibition of PGE2 production by auranofin might be partly due to the inhibition of NO production, and the inhibition of NO production by auranofin be partly due to the inhibition of PGE2 production. In conclusion, auranofin inhibits both PGE2 production and NO production by inhibiting the upregulation of mRNA levels of COX-2 and NOS.

We gave general anesthesia using sevoflurane to a patient undergoing cadaveric renal transplantation. Although the maximum inorganic fluoride concentration in the serum was unexpectedly high (74 uM) in the perioperative period, urine output from the transplanted kidney started simultaneously with reperfusion of the kidney and renal functions also recovered swiftly. Enzyme induction caused by anticonvulsants, which had been administered prior to operation, was assumed to be the cause of the elevation in serum inorganic fluoride concentrations in the patient. We recognized that inorganic fluoride ion is not a primary factor to aggravate functions of the transplanted kidney and concluded that sevoflurane could be selected as a volatile anesthetic used in renal transplant surgery.

A weakly tumorigenic cell clone (QR-32) derived from a murine fibrosarcoma (BMT-11) grew lethally in 6 out of 10 syngeneic C57BL/6 mice after co-implantation with gelatin sponge. All six cell lines (QRsP) established from the arising tumors from QR-32 had enhanced tumorigenicity and/or pulmonary metastatic ability in vivo, indicating that those QRsP cell lines acquired progressed phenotypes as compared with those of QR-32 cells. In contrast, the frequency of tumor progression was suppressed to 50% (3/6) in the cell lines (QRsP/PSK) established from those arising in the mice treated with an immunopotentiating protein-bound polysaccharide, PSK. The enhanced metastatic ability was accompanied by enhanced expressions of a tumor-associated transcription factor, E1AF and by increased production of matrix metalloproteinase (MMP) in five lines of QRsP and two lines of QRsP/PSK. It was found that administration of PSK augmented the production of an antioxidative enzyme, manganese superoxide dismutase (Mn-SOD), in the tumor tissues co-implanted with gelatin sponge. PSK administration also brought about up-regulation of interferon-gamma (IFN-gamma)-expression and down-regulation of transforming growth factor-beta (TGF-beta)-expression in the tumor tissues, which were examined by RT-PCR on day 7, 14 and 21 after the co-implantation. Other inflammatory cytokines such as interleukin-1 alpha (IL-1 alpha) and tumor necrosis factor-alpha (TNF-alpha) were expressed equally both in PSK-treated and untreated tumor tissues. In vitro experiments proved that although IFN-gamma did not increase the production of Mn-SOD by itself, concomitant treatment with both IFN-gamma and TNF-alpha enhanced the Mn-SOD-production in QR-32 cells greatly. On the contrary, TGF-beta treatment lowered the Mn-SOD level in QR-32 cells. PSK-treatment did not induce Mn-SOD in cultured QR-32 cells directly. These results indicated that PSK inhibits the malignant progression of QR-32 cells promoted by co-implantation with gelatin sponge, most possibly through elevating the Mn-SOD level in QR-32 cells via modulation of the production of inflammatory cytokines, that is, increasing IFN-gamma and decreasing TGF-beta at the site of tumor growth.

We examined the modulatory effect of serotonergic activities on haloperidol-induced up-regulation of dopamine D2 receptors in rat striatum. Chronic treatment with haloperidol (0.1, 0.5 mg/kg, i.p., 3 weeks) increased the number of dopamine D2 receptors, while no increase was observed with atypical antipsychotic drugs clozapine (10 mg/kg) and ORG 5222 (0.25 mg/kg). Chronic treatment with MK 212, a serotonin (5-HT)2A/2C receptor agonist (2.5 mg/kg), or with citalopram, a 5-HT reuptake inhibitor (10 mg/kg), potentiated the haloperidol (0.1 mg/kg)-induced up-regulation of dopamine D2 receptor, while that with (+/-)-8-hydroxy-2-(di-n-propylamino) tetralin (8-OH-DPAT), a 5-HT1A receptor agonist (0.1 mg/kg), had no influence on the dopamine D2 receptor up-regulation. Co-administration of ritanserin (1 mg/kg), a 5-HT2A/2C receptor antagonist, with a low dose of haloperidol (0.1 mg/kg), but not with a high dose of the agent (0.5 mg/kg), attenuated the dopamine D2 receptor up-regulation. Drug occupation of 5-HT2A and dopamine D2 receptors in vivo examined with use of N-ethoxycarbonyl-2-ethoxy-1,2-dihydroquinoline (EEDQ) was 69.8% and 45.1%, respectively, after the acute administration of haloperidol (0.1 mg/kg) plus ritanserin (1 mg/kg). This profile that 5-HT2A receptors were highly occupied compared with dopamine D2 receptors was similar to that of clozapine or ORG 5222. These results suggest that potent 5-HT2A receptor antagonism versus weak dopamine D2 receptor blockade may be involved in the absence of up-regulation of dopamine D2 receptors after chronic treatment with clozapine or ORG 5222.

Estrogens are clearly carcinogenic in humans and rodents, but the mechanisms by which these hormones induce cancer are only partially understood. Stimulation of cell proliferation and gene expression by binding to the estrogen receptor is one important mechanism in hormonal carcinogenesis; however, estrogenicity is not sufficient to explain the carcinogenic activity of all estrogens because some estrogens are not carcinogenic. Estrogens are nonmutagenic in many assays, but exhibit specific types of genotoxic activity under certain conditions. We have studied extensively the mechanisms by which estrogens induce neoplastic transformation in a model in vitro system. Diethylstilbestrol (DES) and 17 beta-estradiol (E2) and their metabolites induce morphological and neoplastic transformation of Syrian hamster embryo (SHE) cells that express no measurable levels of estrogen receptor. The estrogens induce DNA adduct formation that is detected by 32P-postlabeling. DNA adduct formation is detected in cells treated with DES, but not in cells treated with either alpha- or beta-dienestrol. Similarly, morphological transformation of SHE calls is induced by treatment with DES, but not by treatment with alpha- or beta-dienestrol. Exposure of SHE treatment cells to E2 and its metabolites 2-hydroxyestradiol and 4-hydroxyestradiol leads to covalent DNA adduct formation, corresponding to the induction of cell transformation. Induction of morphological transformation of SHE cells by estrogens correlates well with the ability of estrogens to induce DNA adduct formation. DNA damage caused by DNA adduct formation may be important in hormonal carcinogenesis. It is clear that hormones affect carcinogenesis by epigenetic mechanisms such as stimulation of cell proliferation of estrogen-dependent target cells and reprogramming of cellular differentiation and gene expression. In addition, significant evidence exists that certain estrogens can also cause genetic alterations by mechanisms not involving the classic estrogen receptor. These findings indicate that hormonal carcinogenesis is most likely a result of the interplay of both genetic and epigenetic factors.

The Fas/Fas ligand (FasL)-mediated apoptosis may play a role in the induction and maintenance of T cell tolerance. To investigate the role of FasL in the apoptosis of lymphocytes in autoimmune diseases, gene and protein expression of FasL were examined in peripheral blood mononuclear cells (PBMC) from patients with systemic lupus erythematosus (SLE) or rheumatoid arthritis (RA), and from healthy donors by a newly-designed semiquantitative reverse transcription (RT)-PCR and flow cytometry. Although no significant difference in FasL gene expression was obtained among three groups, SLE patients exhibited a wide distribution of the values. In SLE patients, there was a significant correlation between FasL gene expression by PBMC and some clinical parameters including SLE Disease Activity Index (SLEDAI) score, anti-DNA antibody titer and complement titer (CH50). More interestingly, a marked increase in FasL gene expression was observed in untreated SLE patients, whereas a significant decrease was observed in prednisolone-treated SLE patients. Flow cytometric analysis revealed the expression of FasL on T cell subsets from SLE patients and on anti-CD3 mAb-stimulated T cells from healthy donors. In vitro experiments, dexamethasone inhibited FasL gene expression by PBMC from healthy donors in a dose-dependent manner and with time of incubation. These results clearly indicate that FasL is up-regulated in active SLE patients, reflecting in vivo T cell activation, and that corticosteroids directly down-regulate FasL gene expression by human PBMC.

Rifamicin, an antituberculosis agent, is one of the most potent inducers of hepatic drug-oxidation enzymes. Rifampicin can reduce the efficacy of several therapeutically important drugs (including verapamil and diltiazem) by accelerating systemic elimination or by increasing hepatic first-pass metabolism. Because dihydropyridine calcium-channel blockers are mainly metabolized by the liver, rifampicin may also increase the extraction of these drugs and thereby reduce their antihypertensive effects. Here we report four possible cases of interaction between rifampicin and dihydropiridine calcium-channel blockers. Rifampicin was given to treat tuberculosis in four elderly hypertensive patients whose blood pressure was well-controlled by one or more dihydropiridine calcium-channel blockers (nisoldipine, nifedipine, or barnidipine and manidipine), shortly after the start of antituberculosis therapy, their blood pressures rose. Either much greater doses of dihydropyridines or additional antihypertensive agents had to be given to keep blood pressure under control. After withdrawal of rifampicin, blood pressure fell in all patients and the doses of the antihypertensive agents had to be reduced. These findings indicate that rifampicin may lessen the antihypertensive effects of dihydropiridine calcium-channel blockers.