Identification and mapping of Rf-I an inhibitor of the Rf5 restorer gene for Cms-C in maize (Zea mays L.)

The restoration of the C-type cytoplasmic male sterility (Cms) has been a common agriculture practice in the production of hybrid seed for many years. In this study, a series of crosses between select sterile and restorer lines, as well as a backcross population of (Cms-C77 x 6233) x 6233, were used to investigate the restoration of C-type Cms. Our results demonstrated that there was an inhibitor of the Rf5 restorer gene. This inhibitor gene, Rf-I, maps to chromosome 7 and is tightly linked with SSR markers, umc2326 and umc2327, at a genetic distance 4.7 and 3.4 cM, respectively. After analyzing our data combined with previous studies, we propose that the restoration of C-type Cms has two dominant genes, Rf4 and Rf5. Rf4 has the ability to restore all genotypes of Cms-C lines; however, there exists an inhibitor for the other restorer gene, Rf5; thus, it can restore only those genotypes of Cms-C lines lacking the Rf-I inhibitor.

The geminal dimethyl analogue of Flurbiprofen as a novel Aβ42 inhibitor and potential Alzheimer’s disease modifying agent

The subtle modification of a selection of Abeta42 inhibiting non-steroidal anti-inflammatory drugs (NSAIDs), through synthesis of the geminal dimethyl analogues, was anticipated to ablate their cyclooxygenase activity whilst maintaining Abeta42 inhibition. Methylflurbiprofen 6 exhibited similar in vitro Abeta42 inhibition to its parent NSAID Flurbiprofen and was further evaluated in the Tg2576 mouse model of Alzheimer's disease and an animal model of gastro-intestinal (GI) impairment, but proved unviable for further clinical development.

Limits to the polarization for spin-exchange optical pumping of 3He

Based on measurements of the temperature dependence of 3He relaxation in a wide range of spin-exchange optical pumping cells, we report evidence for a previously unrecognized surface relaxation process. The relaxation rate was found to be linearly proportional to the alkali-metal density with a slope that exceeds the spin-exchange rate, which limits the polarization for current applications, including neutron spin filters, polarized targets, and polarized gas magnetic resonance imaging. We find that the magnitude of this excess relaxation can vary widely between cells, and that the variation is larger for cells of higher surface to volume ratio. We have observed 3He polarization as high as 81%, but further improvements require understanding the origin of this relaxation.

[Value of elective neck dissection in patients with clinically stage I squamous cell carcinoma of the tongue]

OBJECTIVE

To determine the value of elective neck dissection in patients with clinically stage I (cT1N0M0) squamous cell carcinoma of the tongue.

METHODS

This was a retrospective study of patients with surgical treatment between November 1984 and November 1999. A total of 130 patients were included in the study, all of whom received operation of the primary site, meanwhile, 99 of whom underwent elective neck dissection simultaneously including level I -III or level I -IV neck dissection in 20 patients and level I - V neck dissection in 79 patients. Results Among all these patients, the rate of occult metastasis to the neck were 12. 0%. Local failure rate in patients with only local treatment, level I II, II, III/IV neck dissection and level I - V neck dissection were 25. 8%, 15. 0% and 7. 6% respectively. There were significant difference in regional failure between patients with only local treatment and patients with elective neck dissection (P < 0.05). Also, no significant differences were noted in the survival rate between patients with only local treatment, elective neck dissection (level I -III or level I -IV) and level I -V neck dissection (P > 0.05).

CONCLUSIONS

Elective neck dissection significantly reduced regional control failure but was not able to reduce distant metastasis or increase the overall survival. A prospective randomized study is worthwhile to further evaluate the benefit of elective neck dissection in the treatment of clinically stage I squamous cell carcinoma of the tongue.

Water soluble prodrug of a COX-2 selective inhibitor suitable for intravenous administration in models of cerebral ischemia

A water soluble choline prodrug (17) of a COX-2 selective inhibitor (16) suitable for intravenous dosing in models of cerebral ischemia has been developed. Constant infusion studies using 17 demonstrate that extrapolated brain levels of 16 may be maintained for over 24h in rats.

Novel approach to pro-drugs of lactones: water soluble imidate and ortho-ester derivatives of a furanone-based COX-2 selective inhibitor

Interest in water soluble COX-2 inhibitors that can be administered intravenously led to the development of novel pro-drugs of a furanone based COX-2 inhibitor 2. Transforming the lactone moiety of the furanone to an imidate or an ortho-ester with a hydrophilic, endogenous appendage resulted in water soluble pro-drugs that converted to the parent drug in vivo.

Polarized (3) He Spin Filters for Slow Neutron Physics

Polarized (3)He spin filters are needed for a variety of experiments with slow neutrons. Their demonstrated utility for highly accurate determination of neutron polarization are critical to the next generation of betadecay correlation coefficient measurements. In addition, they are broadband devices that can polarize large area and high divergence neutron beams with little gamma-ray background, and allow for an additional spin-flip for systematic tests. These attributes are relevant to all neutron sources, but are particularly well-matched to time of flight analysis at spallation sources. There are several issues in the practical use of (3)He spin filters for slow neutron physics. Besides the essential goal of maximizing the (3)He polarization, we also seek to decrease the constraints on cell lifetimes and magnetic field homogeneity. In addition, cells with highly uniform gas thickness are required to produce the spatially uniform neutron polarization needed for beta-decay correlation coefficient experiments. We are currently employing spin-exchange (SE) and metastability-exchange (ME) optical pumping to polarize (3)He, but will focus on SE. We will discuss the recent demonstration of 75 % (3)He polarization, temperature-dependent relaxation mechanism of unknown origin, cell development, spectrally narrowed lasers, and hybrid spin-exchange optical pumping.

Signals in the activation of opioid mu-receptors by loperamide to enhance glucose uptake into cultured C2C12 cells

In an attempt to understand the signal pathways of opioid mu-receptors for glucose metabolism, we used loperamide to investigate the glucose uptake into the myoblast C2C12 cells. Loperamide enhanced the uptake of radioactive deoxyglucose into C2C12 cells in a concentration-dependent manner that was abolished in cells pre-incubated with naloxone or naloxonazine at concentrations sufficient to block opioid mu-receptors. Pharmacological inhibition of phospholipase C (PLC) by U73122 resulted in a concentration-dependent decrease in loperamide-stimulated uptake of radioactive deoxyglucose into C2C12 cells. This inhibition of glucose uptake by U73122 was specific since the inactive congener, U73343, failed to modify loperamide-stimulated glucose uptake. Moreover, both chelerythrine and GF 109203X diminished the action of loperamide at concentrations sufficient to inhibit protein kinase C (PKC). The obtained data suggest that an activation of opioid mu-receptors in C2C12 cells by loperamide may increase glucose uptake via the PLC-PKC pathway.

Randomization of heavily damaged regions in annealed low energy Ge+-implanted (0 0 1)Si

Apparent growth of amorphous layers during low temperature annealing was observed in low energy Ge(+)-implanted (001)Si by high-resolution transmission electron microscopy. The occurrence of abnormal growth is due to the randomization of heavily damaged regions beneath the original amorphous/crystalline interfaces. The randomization process is attributed to the strain, incurred by the presence of a high density of large Ge atoms in the heavily damaged Si substrate, relaxation to lower the free energy of the systems. The randomization upon annealing may be fruitfully applied to minimize the transient enhanced diffusion in shallow junction formation.

Release of beta-endorphin by caffeic acid to lower plasma glucose in streptozotocin-induced diabetic rats

The role of alpha 1A -adrenoceptors in the regulation of opioid secretion from the adrenal glands of streptozotocin-induced diabetic rats (STZ-diabetic rats) was examined in an attempt to determine the mechanism of plasma glucose-lowering action of caffeic acid. In agreement with a previous report, we showed that caffeic acid produced a dose-dependent lowering of the plasma glucose concentration in STZ-diabetic rats along with an increase of plasma beta-endorphin-like immunoreactivity (BER). These actions of caffeic acid were abolished by pretreatment with WB 4101 or RS 17 056 at doses sufficient to block alpha 1A -adrenoceptors. In addition, naloxone and naloxonazine at doses effective for blocking opioid micro -receptors abolished the plasma glucose-lowering action of caffeic acid. Also, unlike that in wild-type diabetic mice, caffeic acid failed to produce a plasma glucose lowering effect in opioid micro -receptor knockout diabetic mice. We observed that caffeic acid could enhance BER release from isolated rat adrenal medulla in a concentration-dependent manner; inhibitors of alpha 1A -adrenoceptors such as WB 4101 and RS 1705 abolished this action. Investigations of the signal pathways further supported that activation of alpha 1A -adrenoceptor is responsible for the stimulatory effect of caffeic acid on BER secretion from the adrenal medulla. In the presence of U73312, a specific inhibitor of phospholipase C, the caffeic acid-induced increase of BER was reduced in a concentration-dependent manner, but it was not affected by U73343, the negative control of U73312. Chelerythrine and GF 109203X also diminished the action of caffeic acid at concentrations sufficient for inhibiting protein kinase C. Moreover, bilateral adrenalectomy in STZ-diabetic rats resulted in the loss of this plasma glucose-lowering effect of caffeic acid, and there was no increase in plasma BER with caffeic acid. Therefore, beta-endorphin release from the adrenal gland appears to be responsible for the lowering of plasma glucose in STZ-diabetic rats induced by caffeic acid, through the activation of alpha 1A -adrenoceptors.

Isolation of non-tuberculous mycobacteria from hospital cockroaches (Periplaneta americana)

This study attempted to isolate mycobacteria from hospital and household cockroaches from 90 hospitals and 40 households in Kaohsiung City and Kaohsiung County, South Taiwan. Among 203 cockroaches (139 Periplaneta americana and 64 Blattella germanica) collected from the hospitals, six Mycobacterium spp. were isolated and identified by polymerase chain reaction-restriction fragment length polymorphism analysis. In 12 cockroaches (P. americana): four Mycobacterium kansaii, three Mycobacterium xenopi, two Mycobacterium gordonae, one Mycobacterium hemophilium, one Mycobacterium fortuitum, and one Mycobacterium avium. However, no mycobacteria were obtained form the hospital B. germanica or 226 household cockroaches (123 P. americana and 103 B. germanica). As cockroach infestation occurs commonly in the hospital environment, they may potentially be implicated as a cause of hospital-acquired infections due to non-tuberculous mycobacteria.

Rough set-based hybrid fuzzy-neural controller design for industrial wastewater treatment

Recent advances in control engineering suggest that hybrid control strategies, integrating some ideas and paradigms existing in different soft computing techniques, such as fuzzy logic, genetic algorithms, rough set theory, and neural networks, may provide improved control performance in wastewater treatment processes. This paper presents an innovative hybrid control algorithm leading to integrate the distinct aspects of indiscernibility capability of rough set theory and search capability of genetic algorithms with conventional neural-fuzzy controller design. The methodology proposed in this study employs a three-stage analysis that is designed in series for generating a representative state function, searching for a set of multi-objective control strategies, and performing a rough set-based autotuning for the neural-fuzzy logic controller to make it applicable for controlling an industrial wastewater treatment process. Research findings in the case study clearly indicate that the use of rough set theory to aid in the neural-fuzzy logic controller design can produce relatively better plant performance in terms of operating cost, control stability, and response time simultaneously, which is effective at least in the selected industrial wastewater treatment plant. Such a methodology is anticipated to be capable of dealing with many other types of process control problems in waste treatment processes by making only minor modifications.

Gamma spectra resulting from the annihilation of positrons with electrons in a single core level

The first gamma spectra associated with the annihilation of positrons with individual core levels (Cu 3p and Ag 4p) are presented. The spectra were obtained by measuring the energy of gamma rays time coincident with Auger electrons emitted as a result of positrons annihilating with a selected core level. Relativistic calculations show good agreement with experiment over a limited range of momenta. However, statistically significant differences indicate that the measurements can provide an impetus to new calculations of many body effects in positron-core electrons annihilation.

Cell culture model for acetaminophen-induced hepatocyte death in vivo

Overdose of the popular, and relatively safe, analgesic acetaminophen (N-acetyl-p-aminophenol, APAP, paracetamol) can produce a fatal centrilobular liver injury. APAP-induced cell death was investigated in a differentiated, transforming growth factor alpha (TGFalpha)-overexpressing, hepatocyte cell line and found to occur at concentrations, and over time frames, relevant to clinical overdose situations. Coordinated multiorganellar collapse was evident during APAP-induced cytotoxicity with widespread, yet selective, protein degradation events in vitro. Cellular proteasomal activity was inhibited with APAP treatment but not with the comparatively nonhepatotoxic APAP regioisomer, N-acetyl-m-aminophenol (AMAP). Low concentrations of the proteasome-directed inhibitor MG132 (N-carbobenzoxyl-Leu-Leu-Leucinal) increased chromatin condensation and cellular stress responses preferentially in AMAP-treated cultures, suggesting a contribution of the proteasome in APAP- but not AMAP-mediated cell death. APAP-specific alterations to mitochondria were observed morphologically with evidence of mitochondrial proliferation in vitro. Biochemical alterations to cellular proteolytic events were also found in vivo, including APAP- or AMAP-mediated inhibition of caspase-3 processing. These results indicate that, although retaining some attributes of apoptosis, both APAP- and AMAP-mediated cell death have additional distinctive features consistent with longer term necrosis.

Effect of triethyltin on Ca2+ movement in Madin-Darby canine kidney cells

The effects of the environmental toxicant, triethyltin, on Ca2+ mobilization in Madin-Darby canine kidney (MDCK) cells have been examined. Triethyltin induced an increase in cytosolic free Ca2+ levels ([Ca2+]i) at concentrations larger than 2 microM in a concentration-dependent manner. Within 5 min, the [Ca2+]i signal was composed of a gradual rise and a sustained phase. The [Ca2+]i signal was partly reduced by removing extracellular Ca2+. In Ca(2+)-free medium, pretreatment with thapsigargin (1 microM), an endoplasmic reticulum Ca2+ pump inhibitor, reduced 50 microM triethyltin-induced [Ca2+]i increase by 80%. Conversely, pretreatment with triethyltin abolished thapsigargin-induced Ca2+ release. Pretreatment with U73122 (2 microM) to inhibit phospholipase C-coupled inositol 1,4,5-trisphosphate formations failed to alter 50 microM triethyltin-induced Ca2+ release. Incubation with triethyltin at a concentration (1 microM) that did not increase basal [Ca2+]i for 3 min did not alter ATP (10 microM)- and bradykinin (1 microM)-induced [Ca2+]i increases. Collectively, this study shows that triethyltin altered Ca2+ movement in renal tubular cells by releasing Ca2+ from multiple stores in an inositol 1,4,5-trisphosphate-independent manner, and by inducing Ca2+ influx.

Mechanism of bradykinin-induced Ca(2+) mobilization in MG63 human osteosarcoma cells

BACKGROUND

The effect of bradykinin on intracellular free Ca(2+) levels ([Ca(2+)](i)) in MG63 human osteosarcoma cells was explored using fura-2 as a Ca(2+) dye.

METHODS/RESULTS

Bradykinin (0.1 nM-1 microM) increased [Ca(2+)](i) in a concentration-dependent manner with an EC(50) value of 0.5 nM. The [Ca(2+)](i) signal comprised an initial peak and a fast decay which returned to baseline in 2 min. Extracellular Ca(2+) removal inhibited the peak [Ca(2+)](i )signals by 35 +/- 3%. Bradykinin (1 nM) failed to increase [Ca(2+)](i) in the absence of extracellular Ca(2+ )after cells were pretreated with thapsigargin (an endoplasmic reticulum Ca(2+) pump inhibitor; 1 microM). Bradykinin (1 nM)-induced intracellular Ca(2+) release was nearly abolished by inhibiting phospholipase C with 2 microM 1-(6-((17 beta-3-methoxyestra-1,3,5(10)-trien-17-yl)amino)hexyl)-1H-pyrrole-2,5-dione (U73122). The [Ca(2+)](i )increase induced by 1 nM bradykinin in Ca(2+)- free medium was abolished by 1 nM HOE 140 (a B2 bradykinin receptor antagonist) but was not altered by 100 nM Des-Arg-HOE 140 (a B1 bradykinin receptor antagonist). Pretreatment with 1 pM pertussis toxin for 5 h in Ca(2+) medium inhibited 30 +/- 3% of 1 nM bradykinin-induced peak [Ca(2+)](i) increase.

CONCLUSIONS

Together, this study shows that bradykinin induced [Ca(2+)](i) increases in a concentration-dependent manner, by stimulating B2 bradykinin receptors leading to mobilization of Ca(2+) from the thapsigargin-sensitive stores in a manner dependent on inositol-1,4,5-trisphosphate, and also by inducing extracellular Ca(2+) influx. The bradykinin response was partly coupled to a pertussis toxin-sensitive G protein pathway.

Effects of Tamm-Horsfall protein and albumin on the inhibition of free radicals

INTRODUCTION

Oxalate in urine can cause tubular cellular damage by the production of free radicals. Then, cell death and cellular debris may promote the retention of calcium oxalate crystals and finally the formation of stones. The two most abundant urinary proteins, Tamm-Horsfall protein (THP) and albumin, were tested for the effects of antioxidants.

MATERIALS AND METHODS

By using xanthine-xanthine oxidase reaction, purified THP and albumin were tested for the inhibitory effect. OD(295) was used as a spectrophotometric method to measure the production of uric acid during the reaction.

RESULTS AND CONCLUSIONS

Both proteins can inhibit the reaction of xanthine oxidase on xanthine, although the effect was decreased after enzymatic deglycosylation of sialic acid. Albumin has an IC(50) of 10.7 nM in native condition and 11.9 nM after deglycosylation, whereas THP has 69.6 nM in native condition and 102.0 nM in deglycosylated condition. The data indicates that THP and albumin have an antioxidant effect. Sialic acid in THP has partly an inhibitory effect and is associated with calcium oxalate formation. Studies have indicated that further investigation of the role of free radicals in the formation of urolithiasis and of sialic acid in protein function is needed.

Effects of Tamm-Horsfall protein and albumin on calcium oxalate crystallization and importance of sialic acids

BACKGROUND

Tamm-Horsfall protein and human serum albumin are common urinary proteins that show uncertain inhibitory action on the crystallization of calcium oxalate monohydrate.

MATERIALS AND METHODS

Batch experiments on crystal nucleation, growth, and aggregation were performed using purified Tamm-Horsfall protein and albumin before and after enzymatic removal of sialic acids from the proteins.

RESULTS

At a concentration of 100 nM, both Tamm-Horsfall protein and albumin promoted the time of crystal nucleation by 18.4% and 8.9%, respectively, relative to the control. However, both of the proteins exerted an inhibitory effect on crystal growth, with the IC(50) being 7.27 nM for Tamm-Horsfall protein and 37.5 nM for albumin. The inhibition of crystal aggregation was 81.82% by Tamm-Horsfall protein 100 nM but only 54.55% at 50 nM after enzymatic removal of the sialic acid. Instead of increasing the inhibition, the effect was changed to promotion after an increase in the concentration of Tamm-Horsfall protein to more than 500 nM for native protein and to more than 100 nM for the enzymatic digest. Albumin showed little change after enzymatic treatment and maintained a maximal inhibitory effect of 72.73% on crystal aggregation when the concentration reached to 100 nM.

CONCLUSION

Because the promotion of nucleation could lessen the subsequent saturation of a calcium oxalate solution, it is concluded that Tamm-Horsfall protein and albumin show an overall effect of inhibition on crystallization in vitro. The inhibitory effect of Tamm-Horsfall protein is partly related to sialic acid.

No association of vitamin D receptor gene BsmI polymorphisms with calcium oxalate stone formation

BACKGROUND AND PURPOSE

The formation of urinary stones is reported to be associated with the vitamin D receptor (VDR). As the most frequently seen polymorphism within the VDR gene is BsmI, it has been used as a genetic marker in searching for the cause of urolithiasis. We aimed to evaluate the association between calcium stone disease and the BsmI polymorphisms.

MATERIALS AND METHODS

A control group of 90 healthy people and a group of 124 patients with calcium oxalate stones were examined. The polymorphism was detected using polymerase chain reaction (PCR)-based restriction analysis. A PCR product length was determined to be 580 bp (BB) whereas two fragments of 405 bp and 175 bp were determined to be excisable (bb) by BsmI endonuclease. Associations between calcium stone disease and BsmI polymorphisms were evaluated.

RESULTS AND CONCLUSIONS

The results revealed no significant difference between normal individuals and stone patients (P = 0.891). The allelic distribution of B and b were similar within both the normal group and the stone patients. Therefore, the BsmI polymorphism of the VDR gene at intron 8 is not a suitable genetic marker for urinary stone disease.

Molecular approach to echinoderm regeneration

Until very recently echinoderm regeneration research and indeed echinoderm research in general has suffered because of the lack of critical mass. In terms of molecular studies of regeneration, echinoderms in particular have lagged behind other groups in this respect. This is in sharp contrast to the major advances achieved with molecular and genetic techniques in the study of embryonic development in echinoderms. The aim of our studies has been to identify genes involved in the process of regeneration and in particular neural regeneration in different echinoderm species. Our survey included the asteroid Asterias rubens and provided evidence for the expression of Hox gene homologues in regenerating radial nerve cords. Present evidence suggests: 1) ArHox1 expression is maintained in intact radial nerve cord and may be upregulated during regeneration. 2) ArHox1 expression may contribute to the dedifferentiation and/or cell proliferation process during epimorphic regeneration. From the crinoid Antedon bifida, we have been successful in cloning a fragment of a BMP2/4 homologue (AnBMP2/4) and analysing its expression during arm regeneration. Here, we discuss the importance of this family of growth factors in several regulatory spheres, including maintaining the identity of pluripotent blastemal cells or as a classic skeletal morphogenic regulator. There is clearly substantial scope for future echinoderm research in the area of molecular biology and certain aspects are discussed in this review.

Relation of BsmI vitamin D receptor gene polymorphism to bone mineral density and occurrence of osteoporosis in postmenopausal Chinese women in Taiwan

Osteoporosis is a common disorder with a strong genetic component. Our aim was to evaluate the correlation of the vitamin D receptor gene intron 8 BsmI polymorphism with bone mineral density (BMD) and their relationship to osteoporosis. We determined the vitamin D receptor gene intron 8 BsmI polymorphfsm using polymerase chain reaction-based restriction analysis in 171 postmenopausal Chinese women in Taiwan. The polymorphism was detected using the restriction enzyme BsmI, where the B allele indicated absence of the cuttable site and the b allele its presence. BMD of the lumbar spine and proximal femur were measured using dual-energy X-ray absorptiometry. The allelic frequencies for postmenopausal Chinese women in Taiwan were 12.3% for B and 87.7% for b in BsmI restriction fragment length polymorphisms. The prevalence of each genotype in the study population was: 6.4% BB, 11.7% Bb and 81.9% bb. The three genotypic groups differed significantly in BMD at the lumbar spine and the femoral neck. These differences corresponded to significant gene-dose effects at the lumbar spine and femoral neck (p<0.001 for both sites). The relative risk for the development of osteoporosis was about 2-3 times as great as that predicted by the differences between genotypes in BMD, and remained significant even after adjustment for age, height and weight. The vitamin D receptor gene intron 8 BsmI polymorphism is associated with reduced BMD and predisposes women to osteoporosis.

Lack of evidence for the association of tumor necrosis factor-alpha gene promoter polymorphism with calcium oxalate stone and bladder cancer patients

Urinary stone disease and bladder cancer are two of the most commonly seen urologic diseases in Taiwan. Tumor necrosis factor-alpha (TNF-alpha) is one of the cytokines secreted by macrophages and is related to a sequence of events in response to inflammation and cancer formation. We investigated the polymorphism of the TNF-alpha gene promoter -308 as a genetic marker in searching for the association between these two commonly seen urologic diseases. One hundred and fourteen patients with transitional cell carcinoma of the urinary bladder and 103 patients with calcium oxalate stone were compared with 150 healthy controls. The polymorphism was detected by polymerase chain reaction-based restriction analysis (Nco I endonuclease). The results revealed no significant differences between normal individuals and the patients with the two commonly seen urologic diseases (P > 0.05). We concluded that the polymorphism of the TNF-alpha promoter -308 is not a valid genetic marker for these two urologic diseases.

Mechanism underlying histamine-induced intracellular Ca2+ movement in PC3 human prostate cancer cells

The effect of histamine on intracellular free Ca2+ levels ([Ca2+]i) in PC3 human prostate cancer cells and the underlying mechanism were evaluated using fura-2 as a Ca2+ dye. Histamine at concentrations between 0.1 and 50 microM increased [Ca2+]i in a concentration-dependent manner with an EC50 value of 1 microM. The [Ca2+]i response comprised an initial rise and a slow decay, which returned to baseline within 3 min. Extracellular Ca2+ removal inhibited 50% of the [Ca2+]i signal. In the absence of extracellular Ca2+, after cells were treated with 1 microM thapsigargin (an endoplasmic reticulum Ca2+ pump inhibitor), 10 microM histamine did not increase [Ca2+]i. After pretreatment with 10 microM histamine in a Ca2+-free medium for several minutes, addition of 3 mM Ca2+ induced [Ca2+]i increases. Histamine (10 microM)-induced intracellular Ca2+ release was abolished by inhibiting phospholipase C with 2 microM 1-(6-((17 beta-3- methoxyestra-1,3,5(10)-trien-17-yl)amino)hexyl)-1H-pyrrole-2,5-dione (U73122), and by 10 microM pyrilamine but was not altered by 50 microM cimetidine. Collectively, the present study shows that histamine induced [Ca2+]i transients in PC3 human prostate cancer cells by stimulating H1 histamine receptors leading to Ca2+ release from the endoplasmic reticulum in an inositol 1,4,5-trisphosphate-dependent manner, and by inducing Ca2+ entry.