Extraneuronal cholinergic system in lymphocytes

Acetylcholine (ACh) is well known as a neurotransmitter in both the central and peripheral nervous systems in mammalian species. Both muscarinic and nicotinic ACh receptors have been identified in lymphocytes isolated from thymus, lymph node, spleen, and peripheral blood, and their stimulation by muscarinic and nicotinic agonists elicits a variety of functional and biochemical effects. On the basis of these findings, it has been postulated that the parasympathetic nervous system may play a role in immune-neurohumoral crosstalk. However, ACh present in the blood of several species has been localized to lymphocytes from various origins using radioimmunoassay. Moreover, using Northern blots or reverse transcription-polymerase chain reaction, expression of choline acetyltransferase, an ACh synthesizing enzyme, has been identified in human blood mononuclear leukocytes, human leukemic T-cell lines, and rat lymphocytes. Stimulation of T-lymphocytes with phytohemagglutinin activates the lymphoid cholinergic system, as evidenced by increased synthesis and release of ACh, increased acetylcholinesterase activity, and the increased expression of mRNA encoding choline acetyltransferase and ACh receptors. The observation that muscarinic receptor stimulation by ACh or agonists increases in [Ca(2)+](i) and up-regulates c-fos expression strongly argues that ACh synthesized and released from T-lymphocytes acts as an autocrine and/or paracrine factor regulating immune function. In summary, these data present a compelling picture in which immune function is not only regulated by the cytokine system, but is also under the control of an independent, lymphoid cholinergic system.

Species differences in oral bioavailability of methotrexate between rats and monkeys

The contributions of incomplete absorption and a first-pass effect to the low bioavailability (BA) of methotrexate (MTX) were evaluated pharmacokinetically in rats and monkeys which respectively have a lower and higher aldehyde oxidase (AO) activity than humans. Plasma concentration profiles of MTX in rats showed linear and nonlinear pharmacokinetics respectively after intravenous (i.v.) and oral dosing of 0.1, 0.5 or 2.5 mg/kg MTX. In rats, most of the dose was excreted as the parent compound into bile and urine after i.v. dosing of 0.5 mg/kg MTX, while the radioactivity was largely eliminated in expired air after oral dosing of 0.5 mg/kg 14C-MTX. Elimination in expired air fell markedly following antibiotics treatment. 7-Hydroxymethotrexate (7-OH-MTX), formed from MTX by AO, was detected in monkey plasma after i.v. and oral dosing of 0.5 mg/kg MTX, but not in rat plasma. The ratio of the cumulative urinary excretion of 7-OH-MTX to MTX in monkeys was higher after oral dosing than after i.v. dosing. The low BA in rats (10% at 0.5 mg/kg) was shown to be mainly due to incomplete absorption, including limited absorption and degradation to 2,4-diamino-N10-methylpteroic acid (DAMPA) and glutamic acid (Glu) by the carboxypeptidase of intestinal bacteria. The low BA in monkeys (5% at 0.5 mg/kg) was shown to be mainly due to the extensive first-pass effect, including metabolism to 7-OH-MTX.

Multipotency of a bone marrow stromal cell line, TBR31-2, established from ts-SV40 T antigen gene transgenic mice

Bone marrow is believed to contain multipotential stromal stem cells which can differentiate into osteoblasts, chondrocytes, adipocytes, and myoblasts (Prockop, D. J. Science 276, 71-74, 1997). Therefore, characterization and identification of the stem-like cell within the stromal cells are important to understand bone marrow function in relation to the hematopoietic microenvironment, and repair/regeneration of tissue defects. TBR31-2 cell, a bone marrow stromal cell line established from bone marrow of transgenic mice harboring temperature-sensitive (ts) simian virus (SV) 40T-antigen gene for immortality, is induced toward both adipocytic and osteogenic cells under conditions of the inactivation of T-antigen (Okuyama, R., Yanai, N., Obinata, M. Exp. Cell Res. 218, 424-429, 1995). In this work, using a semiquantitative reverse transcriptase-polymerase chain reaction (RT-PCR) analysis, mRNA expressions of tissue-specific differentiation markers for adipocyte (lipoprotein lipase), osteoblast (type I collagen and osteocalcin), chondrocyte (type II and X collagen), and muscle cell (desmin) were examined during a long-term culture of the cell. In addition, histochemical studies showed the appearance of adipocytic, osteoblastic, chondrocytic, and muscle cells during this long-term culture. Thus, TBR31-2, which has characteristics of an undifferentiated cell, has the potential to express the multipotential cell lineages. These results indicated that a multipotential progenitor cell including potential to differentiate into a muscle cell and which is situated in the mesenchymal cell lineage was first obtained.

Critical period for adverse effects on development of reproductive system in male offspring of rats given di-n-butyl phthalate during late pregnancy

The objective of this study was to determine the susceptible days for the adverse effects of di-n-butyl phthalate (DBP) on development of reproductive system in male offspring following maternal administration on successive 3-day period during late pregnancy. Pregnant rats were given DBP by gastric intubation at 1000 or 1500 mg/kg on days 12-14 or 18-20 of pregnancy or at 500, 1000 or 1500 mg/kg on days 15-17 of pregnancy. A significant decrease in the maternal body weight gain and/or food consumption was found in the DBP-treated groups regardless of the days on which DBP at 1000 and 1500 mg/kg was given. A significant increase in the number of resorptions per litter was found in the groups given DBP at 1500 mg/kg on days 12-14 and 15-17 of pregnancy. The weights of male and female fetuses were significantly decreased in the groups given DBP at 1000 and 1500 mg/kg on days 12-14 and 18-20 and at 1500 mg/kg on days 15-17. A significant increase in the incidence of fetuses with undescended testes was found at 1500 mg/kg on days 12-14 and at all doses on days 15-17. A significant decrease in the anogenital distance (AGD) of male fetuses was observed in the groups treated with DBP regardless of the days of treatment. The AGD/body weight ratio in male fetuses was significantly reduced in the groups given DBP on days 15-17, but neither on days 12-14 nor 18-20. The AGD of female fetuses in the DBP-treated groups was comparable to that in the control group. It was concluded that period of days 15-17 of pregnancy was the most susceptible for DBP-induced undescended testes and decreased AGD in male offspring.

Critical period for adverse effects on development of reproductive system in male offspring of rats given di-n-butyl phthalate during late pregnancy

The objective of this study was to determine the susceptible days for the adverse effects of di-n-butyl phthalate (DBP) on development of reproductive system in male offspring following maternal administration on successive 3-day period during late pregnancy. Pregnant rats were given DBP by gastric intubation at 1000 or 1500 mg/kg on days 12-14 or 18-20 of pregnancy or at 500, 1000 or 1500 mg/kg on days 15-17 of pregnancy. A significant decrease in the maternal body weight gain and/or food consumption was found in the DBP-treated groups regardless of the days on which DBP at 1000 and 1500 mg/kg was given. A significant increase in the number of resorptions per litter was found in the groups given DBP at 1500 mg/kg on days 12-14 and 15-17 of pregnancy. The weights of male and female fetuses were significantly decreased in the groups given DBP at 1000 and 1500 mg/kg on days 12-14 and 18-20 and at 1500 mg/kg on days 15-17. A significant increase in the incidence of fetuses with undescended testes was found at 1500 mg/kg on days 12-14 and at all doses on days 15-17. A significant decrease in the anogenital distance (AGD) of male fetuses was observed in the groups treated with DBP regardless of the days of treatment. The AGD/body weight ratio in male fetuses was significantly reduced in the groups given DBP on days 15-17, but neither on days 12-14 nor 18-20. The AGD of female fetuses in the DBP-treated groups was comparable to that in the control group. It was concluded that period of days 15-17 of pregnancy was the most susceptible for DBP-induced undescended testes and decreased AGD in male offspring.

Pharmacological properties of traditional medicines. XXVI. Effects of Sansohnin-to on pentobarbital sleep in stressed mice

We investigated the effect of Sansohnin-to (SAT) on changes of duration in sodium pentobarbital (PB)-induced sleeping time caused by five types of stress. SAT reversed shortened PB sleep in repeated cold stress or 45 min-restraint stress tests and the prolonged PB sleep in 120 min-restraint stress. SAT did not reverse the shortened PB sleep in the specific stress state caused by an alternating rhythm in temperature stress or social isolation stress. In addition, SAT influenced both shortened PB sleep in 45 min-restraint stress and prolonged PB sleep in 120 min-restraint stress. SAT had no effect on PB sleep in unstressed control mice. These findings suggest that SAT has unusual activity, different from synthetic narcoleptics such as benzodiazepine. This is because SAT had no effect on PB sleep in unstressed mice, and it reverses stress-induced decrease and/or increase in PB sleep by improving stress-induced functional changes in the central nervous system, rather than by acting like a synthetic hypnotic on the gamma-aminobutyric acidA (GABA(A)) receptor.

COLLABORATIVE WORK TO EVALUATE TOXICITY ON MALE REPRODUCTIVE ORGANS BY REPEATED DOSE STUDIES IN RATS : OVERVIEW OF THE STUDIES

The National Institute of Health Sciences and 28 member companies of the Japan Pharmaceutical Manufacturers Association (JPMA) have conducted a validation study intended to examine whether or not lesions in the male reproductive organs noted in 4-week treatment studies can also be detected after 2-week treatment. In this study, lesions in the male reproductive organs after 2-week treatment were, therefore, compared with those after 4-week treatment. A total of 24 test substances was evaluated, these being nucleic acid modulators, cell division inhibitors, central hormonal modulators, hormonal drugs and their antagonists, other drugs and general chemicals. Among these substances, theophylline did not cause any appreciable lesions in the male reproductive organs even after 4-week treatment in the preliminary studies. With busulfan, data reported in the literature was not reproduced in the preliminary study and all animals died. Therefore, detailed examinations were not conducted for busulfan and theophylline. The remaining 22 test substances, when given to animals for 2 weeks at doses equal to or higher than for 4-week treatment, caused lesions similar to those noted after 4 weeks. It is evident from these findings that effects of pharmaceuticals on the male reproductive organs can be detected in most cases with 2-week treatment.

[Autologous blood transfusion in surgery of urologic malignant tumor]

BACKGROUND

Autologous blood transfusion has been widely endorsed, because of the adverse effects attributed to homologous blood transfusion. So we employed autologous blood transfusion to avoid homologous blood transfusion in operation of urological malignant patients. We reviewed our experience with autologous blood transfusion in 48 patients.

METHODS

A total of 48 patients underwent operation with 400 to 1,200 ml preoperative autologous blood donation, in 41 patients with administration of erythropoietin and 7 patients without erythropoietin. The details of operations are radical nephrectomy in 18 cases (2 cases were bilateral), radical nephro-ureterectomy in 2 cases, retroperitoneal lymph node dissection (RPLND) in 2 cases, radical prostatectomy in 12 cases and radical cystectomy in 14 cases.

RESULTS

The volume of surgical blood loss were 381 +/- 522 ml in nephrectomy (1,158 +/- 202 ml in bilateral case), 517 +/- 5 ml in radical nephro-ureterectomy 636 +/- 574 ml in RPLND, 665 +/- 291 ml in radical prostatectomy and 1,123 +/- 417 ml in radical cystectomy. Only three cases needed homologous blood transfusion.

CONCLUSION

We can avoid homologous blood transfusion in 94% of patients. Autologous blood transfusion is recommended as safe and convenient.

Development of a new type nozzle and spray-drier for industrial production of fine powders

Sophisticated nozzle and spray-drier were newly developed. The nozzle type was that of four-phase spraying, where two liquid streams and two air streams were blown off. The spray pattern from the nozzle was of a hollow-cone type. Mean diameter of droplets in the mist was 13.2 microm in weight average in the condition of blowing at 776 g/min in air flow and 500 ml/min in liquid flow. That is, the weight-based flow ratio of air to liquid was as small as 1. 55. The geometric standard deviation of the droplet size was less than 1.65. This nozzle was still available for a concentrated suspension up to 27% solid without formation of the sludge on the orifice. Thus, fine powder with 1.99 microm in mean diameter was obtained by means of the nozzle and the spray-drier newly developed by us. These are promising for industrial production of the fine powder with low energy and high recovery.

Effects of dibutyl phthalate on reproductive function in pregnant and pseudopregnant rats

In our previous studies, dibutyl phthalate (DBP) was found to be embryolethal and teratogenic in rats. In this study, the effects of DBP on reproductive function were investigated on pregnant and pseudopregnant rats. Rats were given DBP by gastric intubation at 0, 250, 500, 750, 1000, 1250 or 1500 mg/kg on Days 0 to 8 of pregnancy and the pregnancy outcome was determined on Day 20 of pregnancy. The same doses of DBP were given to pseudopregnant rats, with an induced decidual cell response, on Days 0 to 8 of pseudopregnancy, and the uterine weight on Day 9 served as an index of the uterine decidualization. DBP caused significant increases in the incidences of preimplantation loss in females successfully mated at 1250 and 1500 mg/kg and of postimplantation loss in females having implantations at 750 mg/kg and above. The uterine decidualization in pseudopregnant rats was significantly decreased at 750 mg/kg and above. These findings suggest that early embryonic loss due to DBP may be mediated, at least in part, via the suppression of uterine decidualization, an impairment of uterine function.

Toluene inhalation induced epididymal sperm dysfunction in rats

Toluene is a widely abused inhaled solvent. This study was designed to determine whether toluene abuse affects the reproductive functions or general health of males. Seven-week-old male Sprague-Dawley rats were exposed to toluene vapor inhalation (0, 4000, or 6000 ppm; 2 h/day) daily for 5 weeks. Exposure-related suppression of body weight gain and food consumption were observed. Salivation and lacrimation were observed during exposure periods and intensified with repeated exposure. Rats exposed to 6000 ppm toluene had decreased spleen and thymus weights, as well as suppressed lymphocyte counts. In 6000 ppm group, the epididymal sperm counts, sperm motility, sperm quality and in vitro penetrating ability to zona-free hamster eggs were significantly reduced, while no exposure-related changes in the testes weight or spermatogenesis within testes were detected. Tail-less sperm heads were seen within zona-free eggs incubated with sperm from rats exposed to 6000 ppm toluene, but not control rats. No significant changes were observed in serum luteinizing hormone, follicle-stimulating hormone, or testosterone levels following 1 month of exposure to 6000 ppm toluene. These results indicate that high concentrations of toluene may directly target sperm in the epididymis and disrupt sperm maturation.

[Prognosis and organ preservation in oropharyngeal cancer treated with radiotherapy]

The records of 102 patients with squamous cell carcinoma of the oropharynx treated at National Sapporo Hospital with external and/or interstitial radiotherapy between 1978 and 1996 were reviewed to evaluate the treatment results, focusing on primary control and functional preservation. Ninety-five patients had been primarily treated with curative intent initially. Of these 95 patients, 4% were in stage I, 19% in stage II, 42% in stage III and 34% in stage IV. Twenty-one patients (22%) had been treated with multidisciplinary chemotherapy, and 19 patients (20%) had been boosted with brachytherapy mainly using Au-198 grains. The cause-specific survival rates at 5 and 10 years were 63% and 52%, respectively. The local control rates at 5 and 10 years were 70% and 51%, respectively. The most important factors affecting local control were the subsite of the primary tumor and N stage. Based on these findings, it is considered that radiotherapy combined with/without chemotherapy except for N3 and the posterior wall type is an effective method of achieving tumor control and preserving organ function, compared with other methods including surgical procedures.

[Actual situations and problems of patients receiving home IVH--trial use of an assessment chart for outpatients]

In order to improve the quality of life (QOL) and continue nursing, we used an assessment chart to investigate the actual situations and problems of the patients receiving home intravenous hyperalimentation (IVH). From January, 1997 to June, 1999, we investigated 20 patients with home IVH. To 7 patients among them, we asked questions using Kurihara's assessment chart for QOL, plus our original questions concerning IVH. The mean age of the patients was 61 years old, and 19 of them had advanced cancers. Forty percent of the patients maintained the IVH all by themselves and 10% of the patients needed the support of their family. The remaining 50% of the patients left all to their family. There were 9 incidents of trouble during the maintenance of the IVH. Almost all patients from whom informed consent had been received were satisfied with the home IVH. On the contrary, all patients who had not given informed consent were not satisfied with the home IVH. According to the results of the assessment chart, even if the total points were low, the points for the IVH were high in the patients had given informed consent. The main reason for lower QOL was pain. The points for the families were lower than those for the patients. They sometimes complained of uneasiness and dissatisfaction with the support they received. We conclude that therapies to improve symptoms and mental state are necessary to satisfy the patients, and that it is important to support not only the patients but also their families.

Changes in macrophage and lymphocyte subpopulations of lymphoid tissues from pigs infected with the porcine reproductive and respiratory syndrome virus (PRRSV)

We used an immunohistochemical method to investigate changes in macrophage and lymphocyte subpopulations in various lymphoid tissues of pigs in the acute phase of porcine reproductive and respiratory syndrome virus (PRRSV) infection. The numbers of CD8+ cells and B-cells varied among lymphoid tissues after PRRSV infection. In the infected pigs, numbers of CD8+ cells increased in systemic lymphoid tissues whereas numbers of B-cells increased in mucosa-associated lymphoid tissues. There was no difference in the distribution of virus-infected cells and macrophages between lymphoid tissues of the infected pigs. These changes may be associated with the establishment of virus persistence or the emergence of concurrent infection in mucosal organs.

Acute myeloid leukemia in the elderly:--159 Nagoya case studies--Nagoya Cooperative Study Group for Elderly Leukemia

To obtain background information on elderly acute myeloid leukemia (AML), unselected data covering 159 patients aged 60 years or over with AML from 14 hospitals in Nagoya, Japan was analyzed retrospectively. Among these patients, 119 had de novo acute AML, 32 had AML which evolved from myelodysplastic syndrome (MDS-AML), and 8 had other types of leukemia. The survey showed that MDS-AML tended to be more prevalent in patients aged 70 years and older and that MDS-AML showed a significantly more severe degree of leukopenia and anemia than de novo AML. MDS-AML also showed a significantly lower complete remission (CR) rate than that of de novo AML [6.9% (2/29) vs 58.3% (67/11), P < 0.01] and significantly shorter survival times than those of de novo AML [median: 3.6 months vs 9.6 months, P < 0.01 (generalized Wilcoxon test; GW]. In de novo AML, the proportion of patients treated with conventional therapy (CT group) decreased significantly, and that of those with attenuated therapy (AT group) increased significantly as age elevated (P < 0.01). The CT group showed a significantly higher CR rate (65.4% vs 41.2%, P < 0.05) and a significantly longer survival period than those of the AT group [median: 11.6 months vs 4.8 months, P < 0.05 (GW)]. Overall survival rates of the older age groups became significantly shorter with aging [P < 0.01 (GW)].

Antitumor activity of KF22678, a novel thioester derivative of leinamycin

KF22678, a novel thioester derivative of leinamycin with the 1-oxo-1,2-dithiolane-3-one moiety, was examined for anti-tumor activity, toxicity in mice and activation mechanism. KF22678 showed a broad antitumor spectrum against human carcinoma xenografts (lung, colon, ovary and prostate). The efficacy of KF22678 was significantly higher than that of cisplatin. KF22678 exhibited low cross-resistance against various drug-resistant cell lines of MDR1 or MRP overexpressing human tumors, and, in addition, exhibited more potent antitumor activity in vivo than ADM against A2780/ADM and KB/MRP xenograft. DL-Buthionine sulfoximine (BSO) pretreatment significantly reduced intracellular glutathione (GSH) level in human lung carcinoma A549 cells, leading to decrease in the cytotoxicity of KF22678, whereas the cytotoxicity of melphalan was augmented by BSO pretreatment. DNA single-strand breaks (SSB) were observed in A549 cells treated with KF22678 and bleomycin. DNA SSB induced by KF22678 was greatly reduced in the presence of BSO in the cells, whereas DNA SSB induced by bleomycin was not. In addition, the antitumor activity of KF22678 against BSO-pretreated human lung carcinoma PC-9 tumor was significantly decreased. These results suggest that the activation of KF22678 by intracellular GSH might be important for DNA SSB and antitumor activity in vitro and in vivo.

Detection of porcine circovirus from lesions of a pig with wasting disease in Japan

A wasting disease characterized by progressive weight loss and dyspnea has been observed in weaning pigs on a farm in Yamagata Prefecture in 1998. Histopathologic findings in an affected pig were bronchointerstitial pneumonia and intracytoplasmic clusters of basophilic inclusions in macrophages of lymph nodes, which were similar to those in pigs with postweaning multisystemic wasting syndrome (PMWS) recently reported in North America and Europe. Porcine circovirus (PCV)-like particles were observed in bronchial lymph node of the pig by electron microscopy, and PCV antigens were detected in the lesions by immunohistochemical staining. PCV DNA was also detected in the lung and tonsil by PCR, and restriction fragment length polymorphism analysis of the PCR products with HinfI showed the same type of the PCV associated with PMWS (pmws PCV). Homology of nucleotide sequences between the PCR product and corresponding regions of published pmws PCV genomes was very high. These results indicated that virus detected in this study was pmws PCV. To our knowledge, this is the first report on the presence of pmws PCV in Japan.

Nardosinone, a novel enhancer of nerve growth factor in neurite outgrowth from PC12D cells

We isolated nardosinone as a neuritogenic substance from Nardostachys chinensis. Nardosinone did not exhibit the neurotrophic activity but caused a marked enhancement of the nerve growth factor (NGF)-mediated neurite outgrowth from PC12D cells. Nardosinone-induced enhancement of the NGF-action was completely blocked by PD98059, a representative mitogen activated protein kinase (MAPK) kinase inhibitor. The microscopic observations indicated that the neurites in response to nardosinone and NGF were quite long and were generally extended to the neighboring cells. These results suggest that nardosinone enhances the NGF-induced neurite outgrowth from PC12D cells probably by amplifying an up-stream step of MAPK kinase in the NGF receptor-mediated intracellular signaling pathway.

Histone deacetylase inhibitors are the potent inducer/enhancer of differentiation in acute myeloid leukemia: a new approach to anti-leukemia therapy

We investigated the effect of the histone deacetylase inhibitors (HDIs), trichostatin A and trapoxin A on leukemia cells and cell lines from the viewpoint of differentiation induction. TSA induced differentiation in erythroid cell lines by itself, whereas it synergistically enhanced the differentiation that was directed by all-trans retinoic acid (ATRA) or vitamin D3 in U937, HL60 and NB4 cells. The combined treatment of HDI with ATRA induced differentiation in ATRA-resistant HL60 and NB4 cells. The transcriptional expression during the treatment with HDI was examined in HL60, U937 and MEG-O1. Cell cycle-regulator genes (p21waf1 and p16INK4A) were upregulated or constantly expressed, erythroid-specific genes (GATA-1, beta-globin) were silent or downregulated, and housekeeping genes (beta-actin and GAPDH) were constantly expressed. Twelve of 35 (34%) clinical samples from AML patients ranging from M0 to M7 also displayed both phenotypical and morphological changes by the treatment with TSA alone. HDIs are thus the potent inducer or enhancer of differentiation in acute myeloid leukemia and regulate transcription in an ordered manner.

Developmental effects of plasticizer butyl benzyl phthalate after a single administration in rats

The objective of this study was to determine the susceptible day for the developmental toxicity of butyl benzyl phthalate (BBP) by a single administration on one of the days during organogenesis. Pregnant rats were given a single dose of BBP by gastric intubation at a dose of 1000 mg kg(-1) on one of days 13-15 of pregnancy and at 1500 mg kg(-1) on one of days 6-16 of pregnancy. Post-implantation embryolethality was found in pregnant rats given on one of days 6-16, except for day 7. Teratogenicity was noted after a single dosing of BBP on one of days 6, 7, 9, 10, 12, 14 and 15. Deformity of the cervical vertebrae frequently was observed after administration of BBP on day 7. Cleft palate and fusion of the sternebrae were found exclusively, after administration of BBP on day 15. It can be concluded that the manifestation of deviant development induced by BBP varies with the developmental stage at the time of administration and that BBP induces two discrete responses from embryos to teratogenicity during early and late organogenesis.

Enhancement of the serotonin-mediated acetylcholine release by repeated desmethylimipramine treatment in the hippocampus of freely moving rats

A possible involvement of serotonin-mediated cholinergic activation in the antidepressant effect of desmethylimipramine (DMI) was investigated by determination of the effects of a single or repeated DMI administration on acetylcholine (ACh) release in the hippocampus using an in vivo microdialysis technique and a radioimmunoassay for ACh. Rats were administered DMI (10 mg/kg, i.p.) acutely or repeatedly for 21 days. A single or repeated DMI administration did not cause any significant effects on the basal ACh release compared with the respective controls. Atropine perfusion in the acutely DMI-treated or control rats increased the ACh release to the same degree. In repeatedly DMI-treated rats, serotonin (5-HT) (1 to 10 microM) perfusion enhanced significantly the ACh release. However, 5-HT in acutely DMI-treated rats enhanced significantly the ACh release only at 10 microM. 5-HT did not cause any changes in ACh release in control rats. Hippocampal 5-HT content of acutely DMI-treated rats was significantly higher than that of saline-treated control rats, while no difference was observed between the repeatedly DMI- and saline-treated rats. These findings suggest, for the first time, that DMI induced a facilitation of cholinergic neurotransmission in the rat hippocampus through the activation of 5-HT-receptor function.

Establishment of permanent cell lines exhibiting vitamin D-dependent expression of beta-galactosidase activity

The active hormonal form of vitamin D3, 1alpha,25-dihydroxyvitamin D3 (1alpha,25(OH)2D3), has been described as a principal mediator of skeletal homeostasis. Treatment of rat osteosarcoma (ROS)17/2.8, an osteoblast-like cell line, with 1alpha,25(OH)2D3 results in a ligand-dependent increase in transcription of the bone-specific osteocalcin gene. We isolated permanent cell lines that were established by transfecting ROS 17/2.8 cells with plasmids consisting of the human osteocalcin gene promoter containing the vitamin D responsive element linked to a bacterial beta-galactosidase gene. In one of many cell lines, especially in clone NK-31, 1alpha,25(OH)2D3 strongly stimulated beta-galactosidase activity. Reverse transcription-polymerase chain reaction analysis also showed endogenous osteocalcin gene expression and beta-galactosidase gene expression in clone NK-31 cells, which paralleled the increase in beta-galactosidase activity. Using a synthetic analogue of 1alpha,25(OH)2D3, 24,24-difluoro-1alpha,25-dihydroxyvitamin D3, we found that the levels of this activity and these gene expressions were nearly parallel to those of 1alpha,25(OH)2D3. 24R,25-dihydroxyvitamin D3 and 25-hydroxyvitamin D3 at high doses (concentration: 10(-7) M) also induced beta-galactosidase activity in clone NK-31. These cell lines, harboring the plasmid-carrying beta-galactosidase gene under the control of the osteocalcin gene promoter, may contribute to studies on the regulation by 1alpha,25(OH)2D3 or to the development of synthetic analogues of 1alpha,25(OH)2D3.

Nerve growth factor increases the synthesis and release of acetylcholine and the expression of vesicular acetylcholine transporter in primary cultured rat embryonic septal cells

Acetylcholine (ACh) is synthesized by choline acetyltransferase (ChAT) in the cytoplasm of cholinergic nerve terminals and transported into synaptic vesicles by vesicular ACh transporter (VAChT). The genes encoding ChAT and VAChT are colocalized within the genome, and their products are known to be coregulated by various neurotrophic factors. In the present study, nerve growth factor (NGF; 100 ng/ml) was shown to enhance expression of VAChT and ChAT mRNA in primary cultured rat embryonic septal cells. By using a radioimmunoassay, we also found that NGF increased both neuronal content and spontaneous release of ACh, which were first detected on day 2 of culture and time-dependently increased up to day 10. Stimulated release of ACh elicited by high K+ (50 mM KCl) was also significantly greater in NGF-treated cells than in control cells. NGF enhanced immunoreactivity to antiserum against VAChT, indicating that the augmented responses were due to, at least in part, increased expression of VAChT protein. In contrast, the numbers of immunocytochemically positive cells were unaffected. Thus, NGF appears to augment ACh synthesis, its transport into synaptic vesicles, and its subsequent release. The data also suggest that NGF facilitates growth and development of cholinergic neurons, but not their survival.

Adverse effects of diphenyltin dichloride on initiation and maintenance of pregnancy in rats

The objective of this study was to characterize the adverse effects of diphenyltin dichloride (DPTCl) during early pregnancy. Following successful mating, female rats were given DPTCl by gastric intubation at 0, 4.1, 8.3, 16.5, 24.8 or 33.0 mg/kg on days 0-3 or days 4-7 of pregnancy. Female rats were sacrificed on day 20 of pregnancy and pregnancy outcome was determined. The pregnancy rate was significantly decreased after administration of DPTCl on days 0-3 at 24.8 mg/kg and on days 4-7 at 33.0 mg/kg. The incidence of preimplantation loss was significantly increased after administration on days 0-3 at 16.5 mg/kg and above and on days 4-7 at 33.0 mg/kg. In females having implantations, the numbers of implantations and live fetuses and the incidences of pre- and postimplantation loss in the groups given DPTCl on days 0-3 were comparable to the controls. The incidence of postimplantation loss was significantly increased after administration of DPTCl on days 4-7 at 33.0 mg/kg. A pair-feeding study revealed no evidence of pre- and postimplantation embryolethality induced by food restriction. It could be concluded that DPTCl during early pregnancy causes early embryonic loss and DPTCl has greater effects on reproduction when administered during earlier than later stages of blastogenesis.