Characteristics of a high-concentration-ammonium sulfate-requiring ammonia-oxidizing bacterium isolated from deodorization plants of chicken farms

A high-concentration-ammonium sulfate-requiring, ammonia-oxidizing bacterium, strain K1, was newly isolated from packed tower biological deodorization plants of chicken farms. The cells of strain K1 are rods (0.1-1.0 x 1.0-2.0 microm), gram negative, obligately aerobic, and nonmotile. Colonies (1-2 mm in diameter) on a plate culture are reddish, circular, and smooth. Intracytoplasmic membranes characteristic of nitrifying bacteria are present. The G+C content of the total DNA is 48.5 mol%. The similarity of 16S rRNA (%) to N. europaea ATCC 25978T (type strain) is 93.77%. This bacterium has a higher optimal growth temperature (35 degrees C) than is usually the case and tolerance up to 40 degrees C. The optimum concentration of ammonium sulfate in the medium is 303 mM, which should make it applicable for use in deodorization plants for enhancing the efficiency of deodorization. Phosphoglycerate kinase (PGK) and triosephosphate isomerase (TIM) were found to possess high specific activities (5700 and 4 x 10(5) U/mg, respectively) compared to the activities of these enzymes in strain ATCC 25978T (300 and 14 U/mg).

Polymerase chain reaction amplification of Trichomonas vaginalis DNA from Papanicolaou-stained smears

DNA from Papanicolaou-stained smears was successfully amplified using the polymerase chain reaction (PCR) to investigate if it could be used for retrospective genome studies, such as for the detection of Trichomonas vaginalis. DNA was isolated from 20 archival Papanicolaou-stained smears (19 cervical and 1 seminal fluid samples) and purified by treatment with proteinase K, phenol/chloroform, and ethanol. The method of recovering DNA from the Papanicolaou-stained smear is very important in the successful amplification of Trichomonas DNA in archival cytological smears. We used a specific sequence and successfully amplified DNA in cytological smears of T. vaginalis using PCR. We conclude that the diagnostic accuracy of the detection of T. vaginalis in cervical smears is enhanced by using a combination of a Papanicolaou-stained smear and PCR.

Flow cytometric analysis of Thy-1 expression in myelodysplastic syndrome

We analyzed the expression of Thy-1 (CD90) antigen on CD34+ bone marrow mononuclear cells (BMMNC) obtained from 25 patients with myelodysplastic syndrome (MDS) by two-color flow cytometry. Five of nine patients (55.6%) with refractory anemia with excess of blasts (RAEB) and two of 16 (12.5%) with RAEB in transformation (RAEB-t) showed more than 20% of Thy-1 expression of their CD34+ BMMNC. Regarding chromosomal abnormalities, -5/5q- or -18 might be correlated with the expression of Thy-1 on CD34+ BMMNC in MDS. Nine patients were analyzed twice, once before and once after leukemic transformation and showed no significant change in Thy-1 expression. These results show that Thy-1 was expressed on CD34+ BMMNC in certain patients with MDS before leukemic transformation and that it was maintained during the disease progression. In contrast, expression of Thy-1 did not seem essential to the leukemic transformation in MDS though the patients with high Thy-1 expression might have poorer prognosis compared with those with low Thy-1 expression.

Effect of L-lactic acid on the absorption of calcium in gastrectomized rats

The effect of dietary L-lactic acid (LA), (0.5, 1.0, or 2.5 g/100 g of diet) on the absorption of calcium in gastrectomized rats was evaluated for 28 d. Calcium phosphate was used as a source of calcium. The apparent calcium absorption ratio and the calcium contents of the femur and tibia in gastrectomized rats fed the control diet were significantly less than those in sham-operated rats. In the gastrectomized rats, the apparent calcium absorption ratio and the calcium contents of bone in the rats fed the lower doses of LA diets (LA 0.5 or 1.0 g/100 g of diet) were not affected; however, the apparent calcium absorption ratio and the calcium contents of bone in the rats fed the highest doses of LA diet (LA 2.5 g/100 g of diet) were greater than those in gastrectomized rats fed the control diet. Dietary LA (2.5 g/100 g of diet) also enhanced the phosphorus absorption and bone phosphorus content in the gastrectomized rats. We speculated that the highest dose of dietary LA might be associated with the dissolving of a water-insoluble form of calcium salt in the diet, thereby facilitating the calcium absorption and resulting in increased bone calcium content in gastrectomized rats.

The beneficial effect of phosphocreatine accumulation in the creatine kinase transgenic mouse liver in endotoxin-induced hepatic cell death

Purpose. The purpose of this study was to investigate the relationship between hepatic energy status and liver injury during sepsis, using transgenic mice which express creatine kinase in the liver catalyzing the phosphocreatine/creatine system. Methods. Creatine kinase transgenic mice were fed with normal rodent chow or chow containing 10% creatine for 5 days. Lipopolysaccharide (0.2 mg/kg) combined with d-galactosamine (600 mg/kg) was administered intraperitoneally. Results. Eighty percent of the creatine-fed transgenic mice had survived at 48 h post-d-galactosamine and lipopolysaccharide administration, compared with none of the normally fed transgenic mice. Hepatic phosphocreatine and ATP levels in the normally fed transgenic mice were significantly lower than those in the creatine-fed transgenic mice before and after lipopolysaccharide combined with d-galactosamine was administered. Massive hepatic hemorrhagic necrosis with apoptosis was seen in response to d-galactosamine and lipopolysaccharide in normally fed transgenic mice. These results are consistent with a significant increase in serum aminotransferase at 8 h. In contrast, there were faint necrotic changes in the liver with minimal cellular infiltration in creatine-fed transgenic mice. Conclusions. Maintenance of hepatic ATP levels protects from sepsis-induced liver injury and mortality.

Inflammation-related scarring after photorefractive keratectomy

PURPOSE

To study two cases of corneal scarring due to trauma (one case) and infection (one case) unrelated to a previous photorefractive keratectomy (PRK) for the correction of myopia.

METHODS

The patients are part of an Institutional Review Board-approved study of the safety and efficacy of PRK. Both patients underwent bilateral, nonsimultaneous corneal ablation based on preoperative spherical equivalent.

RESULTS

Seven months after PRK, the first patient sustained an alkali burn in one eye that caused severe corneal scarring and myopic regression. The other patient developed bilateral keratoconjunctivitis, more intense in the right eye (1 month after the operation) than in the left eye (4 months after the operation). This right eye subsequently developed diffuse scarring and loss of visual acuity.

CONCLUSION

Patients who have undergone PRK may develop severe corneal scarring after relatively mild ocular traumas or infections.

Evidence of apoptosis induced by myocardial ischemia: A case of ventricular septal rupture following acute myocardial infarction

Recent studies have reported that apoptosis may be induced by reperfusion injury following ischemia in cardiomyocytes. We present a case with evidence of apoptosis induced by myocardial ischemia without reperfusion. DNA fragmentation was demonstrated in the nuclei of the myocardial cells surrounding the ventricular septal rupture following acute myocardial infarction without reperfusion in the infarct-related left anterior descending coronary artery. This finding suggests that ischemia without reperfusion may induce apoptosis in myocardial cells.

Effects of soy milk and bifidobacterium fermented soy milk on lipid metabolism in aged ovariectomized rats

The effects of soy milk and fermented soy milk on lipid metabolism were studied in aged ovariectomized rats. Twenty 8-mo-old Wistar rats were randomly assigned to four treatment groups: sham-operated + control diet (sham-C); ovariectomized (OVX) + control diet (OVX-C); OVX + soy milk diet (OVX-SM); and OVX + fermented soy milk diet (OVX-FSM). The rats were fed on these diets for 6 weeks. Ovariectomy induced an increase in the plasma cholesterol level by 40%. The plasma total cholesterol level of the OVX-FSM rats was decreased by 20% compared to that of the OVX-C rats. The plasma total cholesterol level of the OVX-SM group was not significantly different from that of the OVX-C and sham-C rats. The plasma triglyceride level of the OVX-FSM rats was lower than that of the sham-C rats. The liver cholesterol content in OVX-SM and OVX-FSM rats was lower than that of the OVX-C rats. The liver triglyceride contents of the sham-C, OVX-SM, and OVX-FSM groups were lower than that of the OVX-C group. Fecal steroid excretion did not differ among the groups. Ovariectomy decreased the uterus weight. The OVX-SM and OVX-FSM groups had the same uterus weights as those of the OVX-C group. Thus, the diet including fermented soy milk prevented the cholesterol elevation induced in rats by ovarian hormone deficiency.

[Analysis of HTLV-II particle formation by recombinant baculovirus system]

Assembly and budding formation of Gag precursor is thought to be important for particle formation in retrovirus. To investigate the role of Gag precursor proteins, Pr53gag, of the HTLV-II (Human T-cell Leukemia Virus type II), we induced the expression of unprocessed Pr53gag in recombinant baculovirus-infected insect cells. The protein was assembled and immature empty particles were released from the insect cells, which were ascertained by Western blotting, sucrose density gradients analysis and electron microscopy. When the Gag-Pro-Pol precursor proteins were expressed by the recombinant baculovirus, mature particles were produced. However, deletion of the pol gene did not affect the viral formation, which was different from the process of virion production of HIV-1. This was explained by the facts that HTLV-II could yield Gag-Pro precursor protein, which was expected to have protease activity by itself. Moreover, the results were consistent with low production of Gag-Pro-Pol precursor proteins, which were translated by double frameshifting.

Endogenous amino acids in budgerigars (Melopsittacus undulatus)

To determine the amount of endogenous amino acids in budgerigars (sekiseiinko, Melopsittacus undulatus), as the first step of evaluating amino acid requirements, three experiments were conducted. In Experiments 1 and 2, transit time of the feeds through the digestive tract in budgerigars was studied. The birds were given free access to a corn-based diet containing 50% barium sulfate in Experiment 1, and Japanese millets (hie, Echinochloa utilis) with 0.5 ml of 50% barium sulfate solution in Experiment 2. At intervals of 0.5 to 2 hr, roentgenography was conducted to identify the position of the barium sulfate in the digestive tract. The results showed that the transit time of pellets and millets in the digestive tract was within 24 and 27 hr, respectively. In Experiment 3, to determine the amount of endogenous amino acids in budgerigars, the excreta were collected for 24 hr, from 27 to 51 hr after fasting. The excreta were hydrolyzed with 6 N hydrochloric acid at 110 degrees C for 22 hr for the determination of amino acids by HPLC. The endogenous Ala, Arg, Leu, Lys, Phe and Val were estimated to be 34.9, 36.8, 18.5, 20.3, 15.3 and 18.9 micrograms/day/BW0.75, respectively, which were higher than those in adult roosters.

The augmentation of intrinsic laryngeal muscle activity by air-jet stimulation of the nasal cavity in decerebrate cats

The purpose of this study was to examine the functional roles of nasal afferents in modulating the activity of the intrinsic laryngeal muscles. The electromyographic activities of the intrinsic laryngeal muscles and major respiratory muscles were recorded in cats during nasal air-jet stimulation. The activities of brainstem respiratory neurons were also recorded to determine which neurons transmit nasal afferent signals to the intrinsic laryngeal motoneurons. These axonal projections were identified by antidromic activation evoked by stimulation to the spinal cord at C4 level and the laryngeal nerve. The length of the respiratory cycle was prolonged and the diaphragmatic activity was decreased during air-jet stimulation of the nasal cavity. In contrast, the activities of both the intrinsic laryngeal adductor and abductor muscles were increased. Examination of the laryngeal reflexes revealed increase in the activities of intrinsic laryngeal motoneurons during both respiratory phases. Most of the respiratory neurons recorded decreased their peak firing rate during air-jet stimulation, reflecting decreased diaphragmatic activity; however, the peak firing rate of the bulbospinal expiratory neurons in the portion of the ventral respiratory group caudal to the obex did not decrease during stimulation. These findings demonstrate the nasal air-jet stimulation decreases the activities of major inspiratory muscles in order to avoid inspiration of foreign bodies into the nasal cavity and augments the activities of intrinsic laryngeal muscles, enabling prompt elicitation of the laryngeal airway reflex. Our findings also suggest that the nasal afferents suppress the major inspiratory activities by way of brainstem inspiratory neurons, but that the activities of intrinsic laryngeal muscles are controlled through undetermined pathway(s) other than the pathway through respiratory neurons.

Effect of L-lactic acid on calcium absorption in rats fed omeprazole

We examined the effect of L-lactic acid on calcium absorption in male Wistar rats made achlorhydric by dietary omeprazole, a proton pump inhibitor. The dietary omeprazole intake (0.03 g/100 g of diet) increased the gastric pH and decreased the apparent calcium absorption ratio. Dietary famotidine (0.03 g/100 g of diet), an H2-receptor antagonist, and lower doses of omeprazole (0.005 or 0.01 g/100 g of diet) did not affect the gastric pH or the calcium absorption. In a second experiment, dietary lactic acid (0.5, 1.0, or 2.5 g/100 g of diet) increased the intestinal calcium absorption dose dependently in rats fed omeprazole (0.03 g/100 g of diet). The gastric pH was significantly decreased only in the rats fed higher doses of lactic acid (1.0, or 2.5 g/100 g of diet). In a third experiment, a dietary sour milk beverage containing lactic acid (0.5 g/100 g of diet) increased the intestinal calcium absorption, but did not affect the gastric pH in rats fed omeprazole (0.03 g/100 g of diet). Although the significance of gastric acid in terms of overall calcium absorption is not known, under the present experimental conditions, the inhibition of gastric acid secretion by dietary omeprazole decreased the apparent calcium absorption, and the dietary lactic acid prevented the calcium absorption in rats fed omeprazole.

CD34+/CD41a+ cells best predict platelet recovery after autologous peripheral blood stem cell transplantation

Reliable markers for megakaryocytic reconstitution after peripheral blood stem cell transplantation (PBSCT) have not been established. To determine a convenient and reliable predictor, we measured the number of megakaryocyte progenitor cells in PBSC grafts by clonogenic and flow cytometric assays. Seventeen patients with hematological and solid malignancies were included in this study. For the clonogenic assay, we used thrombopoietin (TPO) as a growth factor to evaluate the maximum number of megakaryocyte progenitor cells. Using a flow cytometric assay, we examined the expression of platelet glycoproteins on CD34+ cells to count the number of megakaryocyte progenitor cells. We used buffer containing EDTA to prevent platelet adhesion to CD34+ cells and selected CD34+ cells by immunomagnetic beads. The best correlation was observed between the number of CD34+/CD41a+ cells and the time to platelet recovery (P = 0.0205), rather than the total number of CD34+ cells. In addition, a close correlation was observed between the number of CD34+/CD41a+ cells and colony-forming unit megakaryocyte (CFU-MK) (P = 0.0018). These observations suggest that the number of CD34+/CD41a+ cells is the best predictor for platelet reconstitution after PBSCT.

A single BIR domain of XIAP sufficient for inhibiting caspases

The inhibitor of apoptosis proteins (IAPs) constitute an evolutionarily conserved family of homologous proteins that suppress apoptosis induced by multiple stimuli. Some IAP family proteins, including XIAP, cIAP-1, and cIAP-2, can bind and directly inhibit selected caspases, a group of intracellular cell death proteases. These caspase-inhibiting IAP family proteins all contain three tandem BIR domains followed by a RING zinc finger domain. To determine the structural basis for caspase inhibition by XIAP, we analyzed the effects of various fragments of this IAP family protein on caspase activity in vitro and on apoptosis suppression in intact cells. The RING domain of XIAP failed to inhibit the activity of recombinant caspases-3 or -7, whereas a fragment of XIAP encompassing the three tandem BIR domains potently inhibited these caspases in vitro and blocked Fas (CD95)-induced apoptosis when expressed in cells. Further dissection of the XIAP protein demonstrated that only the second of the three BIR domains (BIR2) was capable of binding and inhibiting these caspases. The apparent inhibition constants (Ki) for BIR2-mediated inhibition of caspases-3 and -7 were 2-5 nM, indicating that this single BIR domain possesses potent anti-caspase activity. Expression of the BIR2 domain in cells also partially suppressed Fas-induced apoptosis and blocked cytochrome c-induced processing of caspase-9 in cytosolic extracts, whereas BIR1 and BIR3 did not. These findings identify BIR2 as the minimal caspase-inhibitory domain of XIAP and indicate that a single BIR domain can be sufficient for binding and inhibiting caspases.

[Relationship between cognitive function and discharge place among stroke patients after rehabilitation]

One hundred and ninety-nine elderly stroke patients, who received rehabilitation treatment, were examined, to clarify the relationship between cognitive function and discharge place. The patients who moved to long-term care facilities showed more severe disabilities of basic activities of daily living (ADL), more frequent incontinence, and lower functional impairments (Brunnstrom stage), compared with those discharged to their home. Multivariate regression analysis was done with discharge place as the dependent variable. Independent variables were age, sex, kind of stroke, rehabilitation period, level of ADL and IQ on Kohs test, or performance IQ on the Wechsler Adult Intelligence Scale. Older age, higher levels of ADLs, and higher scores on Kohs test IQ or Wechsler Adult Intelligence Scale Performance IQ were all significantly linked with home discharge. These results suggest that non-verbal cognitive dysfunction may affect discharge place in elderly stroke patients after rehabilitation therapy.

Granzyme release and caspase activation in activated human T-lymphocytes

Recently it has been reported that caspase-3 activation occurs in stimulated T-lymphocytes without associated apoptosis (Miossec, C., Dutilleul, V., Fassy, F., and Diu-Hercend, A. (1997) J. Biol. Chem. 272, 13459-13462). To explore this phenomenon, human peripheral blood lymphocytes (PBLs) were stimulated with mitogenic lectins or anti-CD3 antibody, and the proteolytic processing of different caspases and caspase substrates was analyzed by immunoblotting. Proteolytic processing of caspases-3 and -7 and the caspase substrates poly(ADP-ribose) polymerase, GDP dissociation inhibitor, and PKCdelta was observed when PBLs were activated in vitro, and lysates were prepared using RIPA buffer which contains 1% Nonidet P-40, 0.5% deoxycholate, and 0.1% SDS. In contrast, when a lysis buffer containing 2% SDS was used, the caspases remained in their zymogen pro-forms, and no proteolytic processing of caspase substrates was detected. Moreover, in experiments using intact cells and a cell-permeable fluorigenic caspase substrate, no caspase activity was observed in activated T-cells, whereas it was clearly detected when PBLs were treated with the apoptosis-inducing anticancer drug etoposide. Since the granzyme B is a direct activator of caspase-3 and its expression is induced following T-cell activation, we tested the effects of anti-GraB, an engineered serpin that specifically inhibits GraB. When the activated T-lymphocytes were lysed in RIPA buffer containing anti-GraB, no proteolytic processing or activation of caspase-3 was observed, strongly suggesting that release of GraB or similar proteases from their storage sites in cytotoxic granules during the lysis procedure is responsible for caspase activation. These findings demonstrate that T-cells do not process caspases upon activation and caution about the method of cell lysis used when studying granzyme-expressing cells.

[A case of surgical treatment for giant pseudoaneurysm of the left ventricle after myocardial infarction]

A 70-year-old male was admitted for acute postero-inferior myocardial infarction. In cardiac catheterization one month later, there was narrowing of the distal left circumflex artery and the aneurysm of the postero-inferior wall of the left ventricle. The echocardiogram strongly suggested the pseudoaneurysm of the left ventricle. At operation, a large postero-inferior aneurysm was densely adherent to the pericardium. After cardiopulmonary bypass was established, the aorta was cross-clamped and cold cardioplegia was infused, the aneurysm was opened without excision of it. There was a 4 cm by 5 cm defect in the postero-inferior wall of the left ventricle, which communicated with the cavity of the aneurysm. The defect was closed with a patch. Pseudoaneurysm of the left ventricle was diagnosed by histological examination. The postoperative course was uneventful and he discharged on 29th day after surgery.

An essential role of myosin light-chain kinase in the regulation of agonist- and fluid flow-stimulated Ca2+ influx in endothelial cells

Cytosolic Ca2+ ([Ca2+]i) plays an important role in endothelial cell signaling. Although it has been suggested that the influx of Ca2+ can be triggered by depletion of intracellular Ca2+ stores, the mechanism (or mechanisms) underlying this phenomenon needs further elaboration. In the present study, involvement of myosin light-chain kinase (MLCK) in the regulation of Ca2+ signaling was investigated in agonist- and fluid flow-stimulated endothelial cells loaded with Ca2+-sensitive dyes. Bradykinin (BK) and thapsigargin caused an increase in [Ca2+]i followed by a sustained rise due to Ca2+ influx from extracellular space and shifted total myosin light-chain (MLC) from the unphosphorylated to the diphosphorylated form. ML-9 (100 microM), an inhibitor of MLCK, abolished Ca2+ influx and prevented MLC diphosphorylation in BK- and thapsigargin-treated cells, but did not affect Ca2+ mobilization from internal stores. Fluid flow stimulation (shear stress=5 dynes/cm2) increased [Ca2+]i and enhanced MLC phosphorylation. ML-9 also inhibited Ca2+ response and MLC phosphorylation in fluid flow-stimulated cells. The Ca2+ influx in response to BK was linearly correlated with the diphosphorylation of MLC in ML-9 treated cells. Effects of ML-5 and ML-7, analogs of ML-9, to inhibit Ca2+ influx paralleled their potencies to inhibit MLCK activity. These findings demonstrate that MLCK plays an essential role in regulating the plasmalemmal Ca2+ influx in agonist- and fluid flow-stimulated endothelial cells. This study is the first to report the close relationship between Ca2+ influx and MLC diphosphorylation.

[Basic activities of daily living of elderly inpatients]

Basic activities of daily living (ADL) together with communication ability (visual, auditory and speech) and frequency of bedside visits by a nurse were assessed in 672 elderly inpatients staying on a certain day in Tokyo Metropolitan Geriatric hospital, which is a specialized general hospital for geriatrics but not a long-stay chronic care hospital. Diseases were divided into seven groups: neurological (N), circulatory (C), respiratory (P), bone and joint (B), malignant (M), dementia (D) and other disorders (O). The purpose of the study was to clarify the functional state of elderly inpatients and to correlate the Barthel indices (BAI) of ADL with disease group, communication ability, frequency of bedside visits, age and gender. Multivariate analysis revealed a significant association of BAI with frequency of bedside visits by a nurse, communication ability, disease group and age. Scores in patients of N and D groups were significantly decreased compared with other diseases in many items composing the BADL. Patients of B group showed significantly decreased scores in mobility, stairs and bathing, while patients of P group had decreased scores for stairs and bathing. Bathing and stairs were the most difficult activities in the BADL. BAI were linearly correlated with transfer. When independence of feeding was lost, the patients were almost totally dependent. The functional state should be assessed in geriatric inpatients where the quality of life of the patients must take priority over other considerations in the decision making for interventions. The BAI is easy to use and reliable and is probably a suitable tool evaluating the BADL in a comprehensive geriatric assessment.

Lombard reflex during PAG-induced vocalization in decerebrate cats

The Lombard reflex occurs when a speaker increases his vocal effort while speaking in the presence of ambient noise. The purpose of this study was to clarify whether the Lombard reflex can be evoked during controlled vocalization in an animal model. In decerebrate cats, repetitive electrical stimulation was applied to the midbrain periaqueductal gray (PAG) to evoke vocalization. Pure tone auditory stimulation was delivered through a loudspeaker. The activities of the laryngeal adductor muscle, diaphragm and external oblique abdominal muscle and the voice intensity were measured during PAG stimulation, in the presence and absence of the auditory stimulation. To clarify the effects of the auditory laryngeal reflex on the activity of laryngeal adductor motoneurons, the amplitude of the laryngeal reflex evoked by single shock stimulation of the superior laryngeal nerve was also measured during respiration, in the presence and absence of auditory stimulation. The sound made by the cats due to PAG-induced vocalization was augmented by exposure to auditory stimulation, and the activities of the laryngeal adductor muscle and external oblique abdominal muscle were also augmented. During respiration, auditory stimulation also increased the amplitude of the laryngeal reflex evoked in the laryngeal adductor muscle. These results demonstrate that the essential neuronal mechanisms for evoking the Lombard reflex exist within the brainstem.

Regulation of bradykinin-stimulated cation entry into endothelial cells by tyrosine kinase

In endothelial cells, bradykinin stimulates the release of intracellular Ca2+, which is followed by the entry of extracellular Ca2+ into the cells. However, the mechanism underlying the Ca2+ entry is not well understood. To investigate the possible implication of tyrosine kinases in bradykinin-mediated Ca2+ signaling in endothelial cells, cultured porcine aortic endothelial cells were loaded with fura-2/AM, and Mn2+ influx into the cells was determined by the quenching of fluorescence intensity of fura-2 at 360 nm excitation. The tyrosine kinase inhibitors genistein and herbimycin A attenuated not only Ca2+ influx but also Mn2+ influx from the extracellular space without affecting the release of Ca2+ from internal stores in bradykinin-treated cells. In contrast to tyrosine kinase inhibitors, the tyrosine phosphatase inhibitor vanadate stimulated Ca2+ influx as well as Mn2+ influx. On the other hand, both an inactive analog of genistein, daidzein, and an inhibitor of diacylglycerol (DAG) kinase, ethylene glycol dioctanoate, were without effect on [Ca2+]i following the stimulation of agonist. These findings suggest that tyrosine kinase is involved in the regulation of cation influx in endothelial cells.