The prevalence of mental health problems in adults with intellectual disabilities in Japan, associated factors and mental health service use.

BACKGROUND: People with intellectual disabilities are more likely than people in the general population to experience life events associated with an increased risk of mental health problems. However, there has been little research in Japan on the prevalence of mental health problems in adults with intellectual disability (ID) or on associated factors and access to relevant services. METHODS: Informants completed the Japanese version of the Psychiatric Assessment Schedule for Adults with Developmental Disabilities Checklist, and questions on the use of mental health services, for 126 adults with ID living in Tokyo. RESULTS: A total of 23.8% of adults with ID had scores above the Psychiatric Assessment Schedule for Adults with Developmental Disabilities Checklist threshold score. Mental health problems were associated with age, gender and life events and not associated with the level of ID or living environment. Approximately 60% of participants with mental health problems were treated by psychiatrists and 6% of them received psychotherapy. CONCLUSION: In the present study, mental health problems occurred in adults with ID at similar frequencies as in previous studies. Adults with ID who experienced mental health problems tended to receive less psychological therapy than the general Japanese population experiencing such problems. This result may indicate poor provision of psychological services for people with intellectual disabilities in Japan.

Retrospective evaluation of the effect of carotid artery stenosis on cerebral oxygen saturation during off-pump coronary artery bypasses grafting in adult patients.

BACKGROUND: It is unknown whether cerebral oxygenation in patients with carotid artery stenosis (CAS) undergoing off-pump coronary artery bypass grafting (CABG) differs from that in patients without CAS. Thus, the effect of the presence of CAS ≥ 50 % on cerebral oxygenation during off-pump CABG in adult patients was evaluated retrospectively. METHODS: Eleven patients with CAS ≥ 50% and 14 patients without CAS ≥ 50% were enrolled. Regional cerebral tissue oxygen saturation (rSO2) was quantified using near-infrared spectroscopy. Mean arterial pressure, cardiac index, central venous pressure (CVP), and rSO2 at specific points were collected, and significant changes in each parameter were detected using repeated analysis of variance. Mean rSO2 and minimum rSO2 during anastomosis were analyzed by one-way analysis of variance. Multiple logistic regression analysis was used to estimate the odds ratio (OR) with 95% confidence interval (CI) for cerebral desaturation (a decrease in rSO2 ≥ 10% from preoperative value). RESULTS: Two patients with CAS ≥ 50% who received complete carotid artery stenting preoperatively were excluded from the analyses. In both patients with and without CAS, a decrease in rSO2 and cardiac index and an increase in CVP were observed during anastomosis. Mean (SD) maximum decrease in rSO2 from preoperative value was 9.2 (12.7) % on the left side and 8.1 (11.7) % on the right side in patients with CAS ≥ 50%, and 13.5 (11.3) % on the left side and 16.1 (9.8) % on the right side in patients without CAS ≥ 50% (p = 0.316). Neurological complications were not identified in both patients with and without CAS ≥ 50%. In multiple logistic regression analysis, CAS ≥ 50% was not associated with an increased risk of cerebral desaturation (OR 0.160, 95% CI 0.036-0.707, p = 0.016), and rSO2 decreased with decreasing cardiac index < 2.0 l/min/m(2) (OR 3.287, 95 % CI 2.218-5.076, p < 0.001). CONCLUSIONS: CAS ≥ 50% was not an independent risk factor of cerebral desaturation during off-pump CABG. Our results suggest that maintaining cardiac output can prevent a decrease in cerebral oxygenation in both patients with and without CAS ≥ 50%.

Perfusion index derived from a pulse oximeter can predict the incidence of hypotension during spinal anaesthesia for Caesarean delivery.

BACKGROUND: Hypotension during spinal anaesthesia for Caesarean delivery is a result of decreased vascular resistance due to sympathetic blockade and decreased cardiac output due to blood pooling in blocked areas of the body. Change in baseline peripheral vascular tone due to pregnancy may affect the degree of such hypotension. The perfusion index (PI) derived from a pulse oximeter has been used for assessing peripheral perfusion dynamics due to changes in peripheral vascular tone. The aim of this study was to examine whether baseline PI could predict the incidence of spinal anaesthesia-induced hypotension during Caesarean delivery. METHODS: Parturients undergoing elective Caesarean delivery under spinal anaesthesia with hyperbaric bupivacaine 10 mg and fentanyl 20 µg were enrolled in this prospective study. The correlation between baseline PI and the degree of hypotension during spinal anaesthesia and also the predictability of spinal anaesthesia-induced hypotension during Caesarean delivery by PI were investigated. RESULTS: Baseline PI correlated with the degree of decreases in systolic and mean arterial pressure (r=0.664, P<0.0001 and r=0.491, P=0.0029, respectively). The cut-off PI value of 3.5 identified parturients at risk for spinal anaesthesia-induced hypotension with a sensitivity of 81% and a specificity of 86% (P<0.001). The change of PI in parturients with baseline PI ≤ 3.5 was not significant during the observational period, while PI in parturients with baseline PI>3.5 demonstrated marked decreases after spinal injection. CONCLUSIONS: We demonstrated that higher baseline PI was associated with profound hypotension and that baseline PI could predict the incidence of spinal anaesthesia-induced hypotension during Caesarean delivery.

Massive macroglossia developing fast and immediately after endotracheal extubation.

We report an unusual case of massive macroglossia that developed very rapidly after neurosurgery in the park bench position with neck flexion. A few minutes after endotracheal extubation, massive macroglossia was noticed with marked protrusion of the tongue from the oral cavity. The patient's hospital stay was prolonged due to difficulty in speaking and eating. Macroglossia is a rare complication; however, it may cause life-threatening airway obstruction. It is important to be prepared for managing post-operative macroglossia and keep in mind that it may develop rapidly, especially after prolonged surgery performed with sustained neck flexion. The patient should be informed of the risk of macroglossia and the associated problems prior to the operation.

Phase III trial of CHOP-21 versus CHOP-14 for aggressive non-Hodgkin's lymphoma: final results of the Japan Clinical Oncology Group Study, JCOG 9809.

BACKGROUND: CHOP-21 has remained the standard chemotherapy for aggressive non-Hodgkin's lymphoma (NHL), and dose intensification is a potential strategy for improving therapeutic results. We conducted a phase III trial to determine whether dose-dense strategy involving interval shortening of CHOP (CHOP-14) is superior to CHOP-21. PATIENTS AND METHODS: A total of 323 previously untreated patients (aged 15-69 years) with stages II-IV aggressive NHL were randomized. The primary end point was progression-free survival (PFS). RESULTS: Treatment compliance was comparable in both study arms. At 7-year follow-up, no substantial differences were observed in PFS and overall survival (OS) between CHOP-21 (n = 161) and CHOP-14 (n = 162) arms. Median PFS was 2.8 and 2.6 years with CHOP-21 and CHOP-14, respectively (one-sided log-rank P = 0.79). Eight-year OS and PFS rates were 56% and 42% [95% confidence interval (CI) 47% to 64% and 34% to 49%], respectively, with CHOP-21 and 55% and 38% (95% CI 47% to 63% and 31% to 46%), respectively, with CHOP-14. Subgroup analyses showed no remarkable differences in PFS or OS for patients stratified as per the International Prognostic Index or by age. CONCLUSION: Dose-intensification strategy involving interval shortening of CHOP did not prolong PFS in advanced, aggressive NHL.

Randomized trial of cyclophosphamide, doxorubicin, and vincristine versus cisplatin and etoposide versus alternation of these regimens in small-cell lung cancer.

Between April 1985 and May 1988, we conducted a randomized study comparing two standard chemotherapy regimens with the same regimens given on an alternating basis in patients with small-cell lung cancer. The patients were randomly assigned to receive cyclophosphamide at a dose of 800 mg/m2 intravenously (IV) on day 1, doxorubicin at 50 mg/m2 IV on day 1, and vincristine at 1.4 mg/m2 IV on day 1 (CAV); cisplatin at 80 mg/m2 IV on day 1 and etoposide at 100 mg/m2 IV on days 1, 3, and 5 (PE); or CAV alternating with PE (CAV/PE). Each regimen was repeated every 3-4 weeks. Three hundred patients were entered in the study, and 288 of them were eligible for analysis (97 for CAV, 97 for PE, and 94 for CAV/PE). The response rates for PE (78%) and CAV/PE (76%) were significantly higher than the rate for CAV (55%), while the complete response rates were similar (14%, 16%, and 15%, respectively). Nine (23%) of 39 patients who failed to respond to the initial CAV regimen responded to PE when they were crossed over. In contrast, only one (8%) of 13 patients responded to CAV after failing to respond to the PE regimen, suggesting that these two regimens were partially non-cross-resistant. The response duration on CAV/PE was significantly longer than that with CAV (P = .004). The survival time with CAV/PE (11.8 months) was superior to that with CAV (9.9 months) (P = .027) or that with PE (9.9 months) (P = .056). In patients with limited disease, the survival in the alternating arm was significantly superior to the survival in the CAV arm (P = .014) or the survival in the PE arm (P = .023). The toxic effects were acceptable in all three chemotherapy regimens. These results favor the alternating chemotherapy over either standard chemotherapy, such as CAV and PE, although the differences are not dramatic.

Antitumor activity of quinocarmycin (KW2152) against various cultured leukemia and lymphoma cell lines in vitro.

Growth inhibitory activity of quinocarmycin citrate (KW2152) against 25 human cultured cell lines derived from leukemias and lymphomas was assessed quantitatively by regrowth assay. EC90 values (drug concentration required for 90% growth inhibition of treated cells) measured at 1-h exposure to the drug in vitro were more than 16 micrograms/ml in five of six T-cell lines derived from T-lymphoma/leukemia, hence they were insensitive to KW2152. On the other hand, four of six B-cell lines derived from B-lymphoma and three of four cell lines derived from non-T, non-B acute lymphoblastic leukemia were sensitive to KW2152 with EC90 values of 0.3 to 2.2 micrograms/ml at 1-h exposure. Six myelomonocytoid cell lines derived from acute myelogenous leukemia were also sensitive with EC90 values of 1.8 to 3.0 micrograms/ml on 1-h exposure, but two myeloid cell lines derived from chronic myelogenous leukemia and one cell line derived from erythroleukemia were insensitive with EC90 values of more than 16 micrograms/ml. The EC90 values of most cell lines decreased as exposure time increased, and those measured at 24-h exposure were similarly low and mostly in the 0.02 to 0.06 micrograms/ml range. The kinetics analysis of growth inhibitory activity of KW2152 revealed that the drug showed time-dependent action. These in vitro results, as correlated with in vivo results reported elsewhere (K. Fujimoto, T. Oka, and M. Morimoto, Cancer Res., 47: 1516-1522, 1987), suggest that daily consecutive or continuous dose therapy as well as single or intermittent large-dose therapy would be worthy of testing in the clinical trial of KW2152.

Leukemic distribution of a human acute lymphocytic leukemia cell line (Ichikawa strain) in nude mice conditioned with whole-body irradiation.

Induction of leukemia in nude mice (BALB/c nu/nu) was attempted by inoculation with a human acute lymphocytic leukemia cell line (Ichikawa strain, maintained in an ascitic form in our institute). Inoculation of the cells i.v. in normal nude mice failed to produce leukemia. However, conditioning with whole-body irradiation (500 rads) resulted in induction of leukemia after i.v. inoculation, especially when such inocluation was performed 3 days after irradiation. The correlation of survival to inoculum size (10(5) to 10(5)) was inversely exponential. Leukemic infiltration was noted in the spleen, lymph nodes, bone marrow, meninges, liver, kidneys, etc., as seen in human leukemia. These cells retained their original cytological characteristics, ultrastructural features, and surface markers and revealed high terminal deoxynucleotidyltransferase activity as T-derived cells. Chromosome analysis revealed aneuploidy in a hypotetraploid range with a mode of 88 chromosomes.

Comparison of acceptor protein specificities on the formation of ADP-ribose.acceptor adducts by arginine-specific ADP-ribosyltransferase from rabbit skeletal muscle sarcoplasmic reticulum with those of the enzyme from chicken peripheral polymorphonuclear cells.

We compared acceptor-protein specificities on the formation of ADP-ribose.acceptor adducts by arginine-specific ADP-ribosyltransferase (EC 2.4.2.31) purified from rabbit skeletal muscle sarcoplasmic reticulum (SR) with those of the enzyme purified from chicken peripheral polymorphonuclear cells (heterophils). Major differences are as follows: (1), p33 and beta/gamma-actin, preferential endogenous acceptor proteins for the modification by the heterophil enzyme (Mishima, K., Terashima, M., Obara, S., Yamada, K., Imai, K and Shimoyama, M. (1991) J. Biochem. 110, 388-394 and Terashima, M., Mishima, K., Yamada, K., Tsuchiya, M., Wakutani, T. and Shimoyama, M. (1992) Eur. J. Biochem. 204, 305-311) were not modified by the SR enzyme. (2), The modification of p33 by the heterophil enzyme was enhanced by addition of polyanions such as DNA while the protein did not function as acceptor for modification by the SR enzyme even in the presence of DNA. (3), To ADP-ribosylate endogenous substrate Ca(2+)-transporting ATPase (EC 3.6.1.38) of rabbit skeletal muscle SR, the SR ADP-ribosyltransferase required polycations such as poly(L-lysine), whereas the heterophil enzyme modified the ATPase in the absence of poly(L-lysine). These results suggest that vertebrate arginine-specific ADP-ribosyltransferase prefers its own acceptor protein for the modification. Some other properties of the SR and the heterophil ADP-ribosyltransferases were also compared.

Deoxyadenosine triphosphate acting as an energy-transferring molecule in adenosine deaminase inhibited human erythrocytes.

Deoxyadenosine triphosphate (dATP) is present in adenosine deaminase (ADA)-deficient or ADA-inhibited human red cells and in the red cells of the opossum Didelphis virginiana. In order to investigate the functions of dATP in the red cell, red cells were treated with 2'-deoxycoformycin (dCf), a powerful inhibitor of ADA, and incubated with phosphate, deoxyadenosine and glucose. These red cells in which ATP was almost completely replaced by dATP, had the same shape, lactate production, nucleotide consumption, stability of reduced glutathione, osmotic fragility and cell deformability as red cells containing ATP. Cells merely depleted of ATP showed reduced viability. This indicates that dATP compensates well for the absence of ATP and acts as an energy-transferring molecule to maintain cell viability. These results indicate that the accumulation of dATP or the reduction of ATP is not the cause of the hemolysis observed after dCf administration.

Effect of polyamines on ADP-ribosylation by chick-embryo-liver nuclei.

Effects of polyamines on poly(ADP-ribose) formation and DNA synthesis in the chick-embryo-liver nuclei were investigated. When 14-day chick-embryo-liver nuclei were incubated with [3H]NAD in the presence of 1 mM spermine, 2.5 mM spermidine, or 3.5 mM putrescine, a 9-fold increase in poly)ADP-ribose) formation was observed. Nuclei treated with nuclease showed high poly(ADP-ribose) synthetase activity as spermine-treated nuclei. However, no further increase in the polymer formation by polyamines was detected in the nuclease-treated nuclei. We found that an increase in the polymer formation by spermine was the result of an increase in both chain length and chain number of the polymer at 2.3- and 6-fold, respectively. The major ADP-ribosylated proteins were determined as two non-histone proteins of Mr 130 000 and 70 000. The experiment of DNA synthesis with nuclei ADP-ribosylated in the presence of spermine showed a 7-fold increase in [3H]dTMP incorporation into the acid-inaoluble fraction. A similar stimulation was also found with nuclei treated with other polysmines, spermidine and putrescine, in the presence of NAD. These results indicate that DNA synthesis in growing tissues containing polyamines at high levels, such as is the case with tumors and the fetus, is stimulated by polyamine-mediated ADP-ribosylation of the nuclear proteins.

Suppression of cell adhesion and spreading activities of fibronectin by arginine-specific ADP-ribosyltransferase from chicken polymorphonuclear leukocytes.

Arginine-specific ADP-ribosyltransferase present in secretory granules of chicken polymorphonuclear leukocytes (so-called heterophils) was shown to be released into the extracellular space by secretagogues (Terashima et al., J. Biochem. 120 (1996) 1209-1215). In the present work, we examined fibronectin as an extracellular target protein of the released transferase. Fibronectin was ADP-ribosylated by purified transferase and stoichiometry of ADP-ribose incorporation into fibronectin was 1.0 mol/mol of fibronectin. Cell adhesion and spreading assays revealed that ADP-ribosylation of fibronectin markedly inhibited the adhesion activity of fibronectin. A proteolytic peptide map of ADP-ribosylated fibronectin demonstrated that the modification occurs in the cell binding domain of fibronectin. ADP-ribosylation of the RGD peptide suggests that the RGD sequence is the modification site in the domain. ADP-ribosylation of fibronectin in plasma means that fibronectin can probably serve as the substrate for extracellularly released ADP-ribosyltransferase in vivo. Thus, in the extracellular space, ADP-ribosyltransferase released from polymorphonuclear leukocytes may perhaps be involved in regulation of cell adhesion process by interfering with the activity of fibronectin.

Loss of poly(ADP-ribose) synthetase activity without change in arginine-specific ADP-ribosyltransferase activity by acid-treatment; application of the treatment to simple assay for transferase in the presence of poly(ADP-ribose) synthetase.

We investigated the effects of acid treatment (pH 3.5) on the activities of arginine-specific ADP-ribosyltransferase (mono(ADP-ribosyl)transferase) (EC 2.4.2.31) and poly(ADP-ribose) synthetase (EC 2.4.2.30) purified from chicken liver, and we observed that the former enzyme retained completely its activity while there was no evidence for activity of the latter enzyme. Kinetic parameters, including Km values for NAD and whole histones in the reaction catalyzed by acid-treated ADP-ribosyltransferase, were the same as those in the reaction catalyzed by non-treated enzyme. The stereospecificities of the reaction forming ADP-ribosylarginine by acid-treated and non-treated ADP-ribosyltransferases were indistinguishable. We made use of this acid treatment to determine ADP-ribosyltransferase activity in chicken and chick-embryo liver extracts, with a filter assay. The enzyme activities (means +/- S.D. for three separate experiments) of 1-year-old chicken and 13-day-old chick embryo livers were 372.7 +/- 80.20 and 110.6 +/- 27.22 nmol ADP-ribose/g wet liver per h, respectively. This acid treatment is useful for filter assay with labelled NAD of arginine-specific ADP-ribosyltransferase in the fraction containing poly(ADP-ribose) synthetase.

ADP-ribosylation suppresses phosphorylation of the L-type pyruvate kinase.

L-type pyruvate kinase (EC 2.7.1.40) purified from pig liver was ADP-ribosylated by incubation with NAD and ADP-ribosyltransferase purified from hen liver nuclei. Maximal incorporation of the ADP-ribose moiety from NAD into the L-type pyruvate kinase was 0.98 mol/mol of subunit. The Km values for NAD and L-type pyruvate kinase were 0.17 mM and 9.7 microM, respectively. ADP-ribosylation of the L-type pyruvate kinase resulted in suppression of the subsequent phosphorylation catalyzed by cAMP-dependent protein kinase. The ADP-ribosylation-induced suppression of phosphorylation of the L-type pyruvate kinase also resulted in suppression of the phosphorylation-induced inactivation. Amino acid analysis, after exhaustive sequential digestion of ADP-ribosyl-L-type pyruvate kinase with pepsin, aminopeptidase M and carboxy-peptidase B showed arginine to be the ADP-ribose-accepting amino acid. These results together with finding of the ADP-ribosyltransferase activity in mammalian liver cytosol (Moss, J. and Stanley, S.J. (1981) J. Biol. Chem. 256, 7830-7833) suggest that ADP-ribosylation may participate in the regulation of the L-type pyruvate kinase activity through changes in the rate of phosphorylation.

Effect of polyamines on purified poly(ADP-ribose) synthetase from rat liver nuclei.

Using the purified enzyme system, we investigated the spermine-induced stimulation of poly(ADP-ribose) formation. In the presence of 2 microgram DNA and 10 mM Mg2+ in a reaction mixture of 0.2 ml, the optimal concentrations of spermine, spermidine and putrescine were 10, 12.5 and 35 mM, respectively. With the omission of Mg2+, there was an increase in optimal concentrations of polyamines without changes in the rate of poly(ADP-ribose) formation. The concentrations of spermine required for maximum synthesis of poly(ADP-ribose) were increased in proportion to the increase in the amount of DNA. Kinetic analysis of poly(ADP-ribose) formation showed a decrease in Km values for NAD with the addition of spermine. The possible relationship of polyions with regard to DNA, spermine and histone in the purified enzyme system was discussed.

Theophylline reduces poly (ADP-ribose) synthetase from chick embryo liver nuclei.

The effect of theophylline on poly(ADP-ribosyl)ation was investigated. The poly(ADP-ribose) synthetase activity in vitro was markedly reduced in the liver nuclei prepared from theophylline-treated chick embryo. This reduction was not due to the enzyme inhibition by theophylline contamination in the nuclear fraction. The hydroxyapatite column chromatographic analysis of [3H]adenosine-labelled poly(ADP-ribose)molecules formed in vivo revealed that the in vivo formation of poly(ADP-ribose)molecules was also decreased by theophylline administration. The theophylline-induced reduction of poly(ADP-ribose) synthesis was not due to either low NAD levels or to a decrease in the chain length of the poly(ADP-ribose) molecule, rather this reduction was derived from a decrease in the number of poly(ADP-ribose) molecule. Possible mechanisms related to reduction of poly(ADP-ribose) synthesis in vivo are discussed.

Possible participation of Ca2+, Mg2+-dependent endonuclease in liver DNA fragmentation after N-methyl-N-nitrosourea treatment.

We examined the fragmentation of DNA treated with N-methyl-N-nitrosourea under conditions in which Ca2+, Mg2+-dependent endonuclease is active. The molecular mass of DNA found in mouse liver slices treated with methylnitrosurea in the presence of Ca2+ plus Mg2+ was 4 X 10(5) Da. Similar results were obtained with a reconstituted system containing partially purified Ca2+, Mg2+-dependent endonuclease and methylnitrosurea-treated DNA. The enzyme extensively cleaved methylnitrosurea-treated DNA, compared with non-treated DNA. The methylnitrosurea-treated nuclear proteins obtained from mouse liver nuclei had no effect on the DNA fragmentation by the enzyme. Using closed-circular DNA treated with methylnitrosurea, the enzyme produced single-strand cuts in the DNA, as was seen in non-treated, closed-circular DNA, however, the rate of hydrolysis was increased. Ca2+, Mg2+-dependent endonuclease thus warrants further investigation, with regard to the precise mechanism of extensive degradation of DNA in cells treated with carcinogenic alkylating agents.

Calcineurin plays a critical role in the development of pressure overload-induced cardiac hypertrophy.

BACKGROUND: Although activation of the Ca(2+)-dependent phosphatase calcineurin has been reported to induce cardiomyocyte hypertrophy, whether calcineurin is involved in pressure overload-induced cardiac hypertrophy remains controversial. METHODS AND RESULTS: We examined in the present study the role of calcineurin in pressure overload-induced cardiac hypertrophy using transgenic mice that overexpress the dominant negative mutant of calcineurin specifically in the heart. There were no significant differences in body weight, blood pressure, heart rate, heart weight, and the cardiac calcineurin activity between the transgenic mice and their littermate wild-type mice at basal state. The activity of calcineurin was markedly increased by pressure overload produced by constriction of the abdominal aorta in the heart of wild-type mice but less increased in the heart of the transgenic mice. Pressure overload induced increases in heart weight, wall thickness of the left ventricle, and diameter of cardiomyocytes; reprogramming of expressions of immediate early response genes and fetal-type genes; activation of extracellular signal-regulated protein kinases; and fibrosis. All these hypertrophic responses were more prominent in the wild-type mice than in the transgenic mice. CONCLUSIONS: These results suggest that calcineurin plays a critical role in the development of pressure overload-induced cardiac hypertrophy.

Isoproterenol activates extracellular signal-regulated protein kinases in cardiomyocytes through calcineurin.

BACKGROUND: Extracellular signal-regulated kinases (ERKs) and calcineurin have been reported to play important roles in the development of cardiac hypertrophy. We examined here the relation between calcineurin and ERKs in cardiomyocytes. METHODS AND RESULTS: Isoproterenol activated ERKs in cultured cardiomyocytes of neonatal rats, and the activation was abolished by chelation of extracellular Ca(2+) with EGTA, blockade of L-type Ca(2+) channels with nifedipine, or depletion of intracellular Ca(2+) stores with thapsigargin. Isoproterenol-induced activation of ERKs was also significantly suppressed by calcineurin inhibitors in cultured cardiomyocytes as well as in the hearts of mice. Isoproterenol failed to activate ERKs in either the cultured cardiomyocytes or the hearts of mice that overexpress the dominant negative mutant of calcineurin. Isoproterenol elevated intracellular Ca(2+) levels at both systolic and diastolic phases and dose-dependently activated calcineurin. Inhibition of calcineurin also attenuated isoproterenol-stimulated phosphorylation of Src, Shc, and Raf-1 kinase. The immunocytochemistry revealed that calcineurin was localized in the Z band, and isoproterenol induced translocation of calcineurin and ERKs into the nucleus. CONCLUSIONS: Calcineurin, which is activated by marked elevation of intracellular Ca(2+) levels by the Ca(2+)-induced Ca(2+) release mechanism, regulates isoproterenol-induced activation of ERKs in cardiomyocytes.