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C C Chen

Publications and source records attributed to C C Chen.

At least 397 records · Page 22Linked to original sources
PubMed1995

Anti-inflammatory effect of magnolol, isolated from Magnolia officinalis, on A23187-induced pleurisy in mice.

In the present study, A23187-induced pleurisy in mice was used to investigate the anti-inflammatory effect of magnolol, a phenolic compound isolated from Chinese medicine Hou p'u (cortex of Magnolia officinalis). A23187-induced protein leakage was reduced by magnolol (10 mg kg-1, i.p.), indomethacin (10 mg kg-1, i.p.) and BW755C (30 mg kg-1, i.p.). A23187-induced polymorphonuclear (PMN) leucocyte infiltration in the pleural cavity was suppressed by magnolol and BW755C, while enhanced by indomethacin. Like BW755C, magnolol reduced both prostaglandin E2 (PGE2) and leukotriene B4 (LTB4) levels in the pleural fluid of A23187-induced pleurisy, while indomethacin reduced PGE2 but increased LTB4 formation. In the rat isolated peripheral neutrophil suspension, magnolol (3.7 microM) and BW755C (10 microM) also suppressed the A23187-induced thromboxane B2 (TXB2) and LTB4 formation. These results suggest that magnolol, like BW755C, might be a dual cyclo-oxygenase and lipoxygenase inhibitor. The inhibitory effect of magnolol on the A23187-induced pleurisy is proposed to be, at least partly, dependent on the reduction of the formation of eicosanoids mediators in the inflammatory site.

Animals↗
PubMed1995

Differentiation of Aspergillus parasiticus from Aspergillus sojae by random amplification of polymorphic DNA.

Aspergillus parasiticus and Aspergillus sojae are two morphologically similar species belonging to the Aspergillus section flavi. A new method to distinguish the two species, the aflatoxin producer A. parasiticus and the koji mold A. sojae, was developed. Single primers with arbitrary sequences were used to generate random amplified polymorphic DNA (RAPD) markers from strains of these two species. Three decamers, OPA-04, OPB-10, and OPR-01, allowed adequate discrimination between strains of A. parasiticus and A. sojae in RAPD analyses. A. sojae was further separated into group I and group II with the three primers. On the other hand, A. parasiticus was divided into group A and group B when amplified with OPA-04 and OPR-10 primers. The previously misidentified stain CCRC 32423 and the misclassified strain CCRC 30227 were identified as Aspergillus flavus and A. sojae, respectively, on the basis of RAPD patterns and morphological characteristics. We suggest that the RAPD technique is a rapid and reliable tool to distinguish A. parasiticus from A. sojae.

Aspergillus↗
PubMed1995

Negative symptoms at discharge and outcome in schizophrenia.

BACKGROUND: The clinical significance in schizophrenia of positive and negative symptoms at discharge was assessed. METHOD: Of schizophrenic patients fulfilling DSM-III criteria, 113 were recruited for this study. Personal, social and psychopathological data were collected and all cases were followed up at one and two years after discharge. RESULTS: The presence of positive symptoms (64 cases), without concomitant negative symptoms, did not predict the follow-up social function and positive symptom score. Conversely, the presence of negative symptoms (31 cases) predicted worse social functioning (P < 0.05 to P < 0.005) and higher positive symptom scores (P < 0.01) at follow-up using MANOVA: Eighteen cases (15.9%) had neither positive nor negative symptoms and had the best clinical outcome. CONCLUSIONS: Negative, but not positive, symptoms assessed at discharge are an important predictor of poor outcome. In addition, negative symptoms may themselves expose a biological vulnerability to the presence of positive symptoms.

Adult↗
PubMed1995

Evaluation of a collagen membrane with and without bone grafts in treating periodontal intrabony defects.

The aim of this study was to compare the clinical regenerative capacity of collagen membrane with and without demineralized freeze-dried bone allografts (DFDBA) in treating periodontal intrabony defects. Ten systemically healthy patients with similar bilateral periodontal defects were scheduled for surgery. Each patient had at least > or = 6 mm clinical probing depth and loss of attachment at selected sites. Baseline measurements included gingival index (GI), plaque index (PI), gingival recession (GR), clinical attachment level (CAL), probing depth (PD), and mobility. At the time of surgery, the defects were randomly assigned to either test (collagen membrane plus DFDBA) or control group (collagen membrane only). Stent to base of the defects, stent to crest bone, crest of bone to base of the defect, and width of the defects were recorded at the time of surgery and reentry. Eight patients returned after 6 months for reentry surgery. Statistical analysis with a paired t test was used to evaluate the treatment effect and comparison between test and control groups. In addition, a McNemar test was used to analyze the significance of GI, PI, and mobility at different times. The result of this study indicated that both the collagen plus DFDBA and the collagen alone treatment groups had a significant decrease of PD (3.4 +/- 0.4 and 3.2 +/- 0.4 mm), gain of CAL (2.3 +/- 0.5 and 2.0 +/- 0.4 mm), and defect fill (1.7 +/- 0.3 and 1.9 +/- 0.9 mm) (P < 0.05) when compared to the presurgery status. However, there was no significant difference in PD, AL, GR, defect fill, crestal bone resorption, GI, PI, or mobility between the test group and control group. No adverse tissue reaction, infection, or delayed wound healing was noted throughout the treatment in either group. This study suggests that the collagen membrane is well tolerated by the human tissues. Both treatments, either collagen membrane plus DFDBA or collagen membrane alone, promoted significant resolution of periodontal intrabony defects. The addition of a bone graft (DFDBA) with a collagen membrane appears to add no extra benefit to the collagen membrane treatment.

Adult↗
PubMed1995

Levels of interleukin-1 beta and interleukin-8 in gingival crevicular fluids in adult periodontitis.

Recent in vitro findings indicate that cytokines represent an important pathway of connective tissue destruction in human periodontitis. The biological effects of interleukin-1 beta (IL-1 beta) and interleukin-8 (IL-8) are relevant in this regard, and the objective of this study was to compare the levels of these molecules in gingival crevicular fluids (GCF) from patients with adult periodontitis (experimental group) and from individuals with clinically healthy gingiva (control group). GCF was collected for 30 seconds using a periopaper strip and the volume of the sample determined. Following elution of the fluid, assays for IL-1 beta and IL-8 were carried out by ELISA. The concentrations (ng/ml) of cytokines were calculated in the original volume of GCF on each strip. The total amounts (pg/site) of cytokines were expressed as the concentrations multiplied by volumes of GCF: The total amounts of IL-1 beta and IL-8 of the experimental group were significantly higher than the control group. The total amounts of both cytokines were markedly reduced following phase 1 periodontal treatment. The clinical parameters were positively related to the total amounts of IL-1 beta and IL-8. IL-1 beta concentrations and total amounts were also positively related to IL-8 suggesting that the GCF IL-8 levels are influenced by local IL-1 beta activities. These data indicate that the total amounts of IL-1 beta and IL-8 exhibited dynamic changes upon severity of periodontal disease. The levels of IL-1 beta and IL-8 in GCF are valuable in detecting the inflammation of periodontal tissue.

Adult↗
PubMed1995

In vitro production of interleukin-6 by human gingival, normal buccal mucosa, and oral submucous fibrosis fibroblasts treated with betel-nut alkaloids.

This study aimed to assess the possibility of a direct effect of betel-nut alkaloids arecoline and arecaidine on cell proliferation and interleukin-6 (IL-6) production by cultured fibroblasts from human normal gingiva, buccal mucosa and oral submucous fibrosis (OSF) buccal mucosa in vitro. Confluent monolayers of fibroblasts were incubated with or without alkaloids in the presence of 10% fetal calf serum for 48 h at 37 degree C in 5% CO2 and air. At the end of the culture period, supernatants were collected and assayed for IL-6 level. The cell proliferation was monitored by determining 5-bromo-2'-deoxy-uridine (BrdU) incorporated into cellular DNA. Except for the fact that arecoline inhibited cell growth at 100 micrograms/ml, arecoline and arecaidine had similar dose-dependent stimulant effects on the proliferation of these three groups fibroblasts. Concentrations of IL-6 in the control culture supernatants were greatest in healthy gingival fibroblasts, followed by normal buccal mucosa and OSF. Also, the presence of fetal calf serum could stimulate IL-6 release. Except for arecoline at the 100 microgram/mg, there were no significant differences in IL-6 levels between treated and control cultures of the same group when the data were expressed with mean +/- S.D.. However, two of six individuals' normal buccal mucosa fibroblasts significantly released less IL-6, and some cases of OSF and healthy gingiva exhibited slightly higher levels of IL-6 when cells were exposed to arecoline or arecaidine in cultures. Such findings suggests that arecoline and arecaidine can enhance cell proliferation and affect fibroblasts to synthesize IL-6. Furthermore, IL-6 may be a contributing molecular factor in the pathological features noted in OSF.

Adult↗
PubMed1995

Role of protein kinase C subtypes alpha and delta in the regulation of bradykinin-stimulated phosphoinositide breakdown in astrocytes.

Cultured astrocytes express bradykinin (BK) receptors coupled to phospholipase C (PLC)-mediated phosphoinositide (PI) hydrolysis. Short term (10- or 90-min) treatment of cells with 1 microM 12-O-tetradecanoylphorbol-13-acetate (TPA) decreased BK-induced PI breakdown, but this inhibitory action was lost after 3-hr TPA treatment. Extended (6- or 24-hr) pretreatment resulted in marked potentiation of the BK response. Western blot analysis using protein kinase C (PKC) isozyme-specific antibodies indicated that astrocytes express PKC-alpha, PKC-delta, and PKC-zeta. With TPA treatment of the cells for various times (10 min, 90 min, 3 hr, 6 hr, or 24 hr), translocation of PKC-alpha and PKC-delta from the cytosol to the membrane was seen after 10- or 90-min treatment and restoration to basal levels in the membrane fraction was seen after 3-hr treatment. However, partial or complete down-regulation of PKC-alpha and PKC-delta was seen after 6- or 24-hr treatment, respectively. No translocation or down-regulation of PKC-zeta was seen after either short term or long term TPA treatment. The inactive phorbol ester alpha-TPA had no effect on BK-induced PI hydrolysis or on the translocation or down-regulation of PKC-alpha and PKC-delta. These results suggest that, in unstimulated astrocytes, both PKC-alpha and PKC-delta, but not PKC-zeta, may exert tonic inhibition of BK-mediated PI turnover. After 10- or 90-min TPA treatment, AIF4(-)--but not Ca2+ ionophore-induced PI hydrolysis was inhibited, whereas [3H]BK binding was unaffected, indicating that the site of action of PKC-alpha and PKC-delta in the BK receptor/G protein/PLC pathway is after the receptor and before PLC, i.e., the G protein. After down-regulation of PKC-alpha and -delta, increases in both AIF4(-)-induced inositol phosphate formation and [3H]BK binding contributed to marked potentiation of BK-induced PI responses. Scatchard plot analysis showed an increase in both the maximal number of binding sites and the binding affinity. Both the up-regulation of [3H]BK binding and the subsequent BK-induced PI turnover were blocked by 0.5 microM cycloheximide, a protein synthesis inhibitor. The increase in AIF4(-)-induced PI hydrolysis after 24-hr TPA treatment was also inhibited by cycloheximide, indicating that new synthesis of BK receptors and G proteins was required after down-regulation of PKC-alpha and PKC-delta.(ABSTRACT TRUNCATED AT 400 WORDS)

Animals↗
PubMed1995

[The effect of needleless electroacupuncture in general anesthesia during laparoscopic surgery].

BACKGROUND: Three kinds of pain-relieving substances, namely, endorphins, enkephalins and dynorphins, can be released by stimulating the relevant acupoints with the dense-disperse mode of nerve stimulator. The neurochemical mechanisms of pain relief by acupoint stimulation have been widely studied and proved. In the present study, we investigated the modulatory effect of needleless electroacupuncture on the inhaled general anesthesia during laparoscopic surgery. METHODS: Forty gynecologic patients of ASA class I-II status, scheduled for elective laparoscopic surgery, were randomly allocated to study and control groups. Induction and intubation were performed in the same fashion and anesthesia was maintained with inhaled general anesthetics: 50% N2O in oxygen and isoflurane, which was adjusted to keep the hemodynamic changes within +/- 10% of their preoperated level. HANS (LY 257), a special nerve stimulator with 2 Hz and 100 Hz dense-disperse wave, was used to stimulate the bilateral Yang Ling Chuan (G34), Zusanli (S36) acupoints in patients of the study group during the surgery. RESULTS: We found that needleless electroacupuncture significantly lowered the volume concentration of isoflurane from 1.0 +/- 0.33% to 0.74 +/- 0.19% (p < 0.05) at 30 min after the start of operation. Furthermore, it also significantly shortened the recovery time from 11.4 +/- 3.3 min to 8.8 +/- 3.2 min (p < 0.05). CONCLUSIONS: Under general anesthesia, the application of needleless electroacupuncture can reduce the volume concentration of isoflurane and shorten the post-anesthetic recovery time during laparoscopic surgery.

Adult↗
PubMed1995

Pituitary apoplexy diagnosed by magnetic resonance imaging: a case report.

Pituitary apoplexy is a neuroendocrine emergency produced by hemorrhage or infarction of pituitary tumors, and its accurate diagnosis has relied mainly on clinical manifestations and computed tomography (CT) scan of sella in the past. A case is reported of pituitary apoplexy which was demonstrated on magnetic resonance imaging (MRI). The 72-year-old male patient was admitted to the Nephrology Section of VGH-Taipei with symptoms of general malaise, poor appetite for four months and apparent hyponatremia (Na 102 mEq/L) on laboratory findings. Under the impression of syndrome of inappropriate secretion of antidiuretic hormone (SIADH), fluid restriction and infusion of isotonic saline were prescribed, but in vain. The patient was transferred to the Endocrinology Section because of lowered serum cortisol, T3, T4, and hs-TSH levels. Dynamic pituitary function tests confirmed the diagnosis of panhypopituitarism. Contrast enhanced CT scan of sella revealed displacement of the pituitary stalk to the right side. T1-weighted MRI showed persistent high intensity in left sella and T2-weighted MRI showed persisting isointense to white matter. The hyponatremia and clinical symptoms resolved within a few days after replacement therapy with glucocorticoid and thyroid hormone. It was concluded that MRI is more sensitive than CT scan for detecting subacute or chronic pituitary apoplexy.

Aged↗
PubMed1995

Lack of sensitivity of indium-111 mixed leukocyte scans for active disease in Takayasu's arteritis.

OBJECTIVE: Currently, a reliable, noninvasive means of detecting the active vasculitic lesions of Takayasu's arteritis does not exist. Based on the cellular infiltrates seen in active lesions, we postulated that indium-111 labelled mixed leukocytes could be used to scintigraphically detect sites of active vasculitis. METHODS: Fifteen In-111 mixed leukocyte scans were performed in 10 patients with Takayasu's arteritis and correlated with clinical, laboratory, and radiographic findings. Patients had either active, stable/smoldering, or inactive disease at the time when 8, 4, and 3 scans were performed, respectively. RESULTS: Two of the 8 scans performed in patients with active disease were positive for increased vessel uptake (sensitivity = 25%). All other scans were interpreted as negative for active arteritis. CONCLUSION: We conclude that In-111 mixed leukocyte scans have a low sensitivity for detection of active Takayasu's arteritis.

Adult↗
PubMed1995

Congenital muscular dystrophy (non-Fukuyama type): a case report.

A Taiwanese girl, aged 12 years, presented with early myogenic hypotonia, multiple joint contractures, mental subnormality and epilepsy. Computerized tomography scanning of the brain showed white matter hyperlucency. According to her clinical manifestations and radiological pictures, the patient could be the fourth oriental case who had the features of occidental-type cerebromuscular dystrophy.

Child↗
PubMed1995

Technetium-99m-sestamibi imaging before reoperation for primary hyperparathyroidism.

UNLABELLED: Recent studies have reported high sensitivities for parathyroid localization with 99mTc-sestamibi and have been performed using either 123I/99mTc-sestamibi or a double-phase sestamibi scanning technique. These studies have focused primarily on patients undergoing initial surgery. We studied 35 patients prior to reoperative surgery to investigate the relative sensitivities of these two technique sin this patient population. METHODS: Double-phase sestamibi scanning (early and delayed imaging) was performed in all patients. Evaluable 123I/99mTc-sestamibi subtraction studies were also obtained in 25 patients. Results were correlated with surgical findings in 32 patients and with clinical outcome in 3 patients in whom mediastinal lesions were radiographically ablated. RESULTS: Overall, double-phase sestamibi imaging detected 23 of 39 abnormal parathyroid glands (59%), whereas 123I/99mTc-sestamibi detected 19 of 27 (70%). Oblique imaging, delayed imaging and 123I subtraction all contributed to sensitivity, and 123I subtraction also proved useful in patients with partial thyroid suppression. Two patients had lesions visible on the early sestamibi images that were not seen at all on the delayed scans. There were four false-positive findings. CONCLUSION: No significant differences between double-phase sestamibi and 123I/99mTc-sestamibi subtraction scanning were found, although the latter tended to be more sensitive.

Adenoma↗
PubMed1995

Follow-up investigations on clinical manifestations after filariasis eradication by diethylcarbamazine medicated common salt on Kinmen (Quemoy) Islands, Republic of China.

From May to December 1993, a house-by-house survey was conducted on the changes in clinical manifestations of filariasis among 814 pre-control mf carriers in 88 villages of five towns/districts on Kinmen Islands. Four hundred and sixteen (51%) pre-control mf carriers were examined physically with history taking. The rates of disappearance, improvement, no change, aggravation, and new occurrence were 72% (229), 6% (26), 14% (59), 6% (24) and 2% (8), respectively. The rates of disappearance and improvement were higher for the acute than for the chronic manifestations. However, these rates were also high for hydrocele and chyluria. These findings indicate that the acute manifestations disappear or greatly improve after filariasis eradication by a low dose of DEC medicated salt for a period of 6 months. However, the chronic ones remain unchanged or even aggravated to become one of the more important public health problems.

Acute Disease↗
PubMed1995

Protein kinase C isoform delta is involved in the stimulation of the Na(+)-H+ exchanger in C6 glioma cells.

Protein kinase C (PKC), the major receptor for tumor-promoting phorbol esters, is a family consisting of at least 12 distinct isoforms. In C6 glioma cells, short term (10 min) treatment with 12-O-tetradecanoyl phorbol-13-acetate (TPA) results in a dose-dependent translocation of PKC alpha, PKC delta and PKC theta. Long term (24 hr) treatment with appropriate doses of TPA results in the complete down-regulation of PKC delta but not of PKC alpha PKC theta. This property was used to determine which isoform might be involved in the activation of the glial cell Na(+)-H+ exchanger. It was found that (a) TPA has dose-dependent effects on PKC alpha, PKC delta, and PKC theta translocation and on Na(+)-dependent, EIPA-sensitive Na(+)-H+ exchanger stimulation; (b) the antiporter is blocked both by staurosporine and in cells in which PKC alpha, PKC delta, and PKC theta have been completely down-regulated; (c) the inactive form (alpha-TPA) of TPA, which does not include translocation of the three isoforms (alpha, delta, and theta) has no effect on the antiporter; (d) Western blot analysis demonstrated dose-dependent TPA (10, 30, 100, and 1000 nM)-induced translocation of PKC alpha, PKC delta, and PKC theta. TPA (10, 30, 100, and 1000 nM)-induced Na(+)-H+ exchanger activation was also found to be dose dependent. There was no difference in TPA-induced Na(+)-H+ exchanger activation between 30 and 100 nM; it correlated with the extent of TPA-induced PKC delta translocation over the same concentration range, suggesting that isoform responsible for the exchanger activation is PKC delta; (e) When 1 microM TPA is added after prior treatment of the cells with 10 nM TPA, an additive effect on Na(+)-H+ exchanger is seen that is not observed when the initial stimulus in 30 nM TPA, as would be expected if the PKC delta isoform were responsible for exchanger activation; (f) Finally, when PKC delta, but not PKC alpha and PKC theta, is completely down-regulated by 24-hr pretreatment with 10, 30, or 100 nM TPA, the Na(+)-H+ exchanger can no longer be stimulated by 1 microM TPA; when 1 nM TPA pretreatment is used, no down-regulation occurs and the exchanger still responds to 1 microM TPA. We have shown that the Na(+)-H+ exchanger in C6 glioma cells can be stimulated by TPA-induced PKC activation and, for the first time, that PKC delta is involved in the activation of this antiporter. Our results also suggest that different members of the PKC family within a single cell elicit specific physiological responses.

Dose-Response Relationship, Drug↗
PubMed1995

A model of experimental acute necrotizing pancreatitis.

BACKGROUND: A model of moderate acute necrotizing pancreatitis is essential for the study of the pathophysiology of the disease and novel therapies. We tried to establish a model of bile salt-induced acute necrotizing pancreatitis in rats. METHODS: Acute pancreatitis was induced by retrograde infusion of bile salt into the cannulated pancreatobiliary duct. Twenty-six rats wee divided into 3 groups. Group I (n = 8) received 0.2 ml of glycodeoxycholic acid (GDOC) 10 mmol/l; group II (n = 10) 0.2 ml of 2.5% sodium taurodeoxycholate (NaTDC); group III (n = 8) the mixture of 0.2 ml GDOC 10 mmol/l and 10 U enterokinase. Serum levels of amylase and lipase, hematocrit, mean arterial pressure and heart rate were determined at baseline and 5 hours later. Then the pancreas was removed for histopathology and grading (0-3; absent-severe) with regard to leukocyte infiltration, edema, necrosis, hemorrhage and acinar cell vacuolization. RESULTS: Serum levels of amylase and lipase increased significantly in 5 hours in all the groups. Serum amylase levels were significantly lower in group III than in group II. No significant difference of serum lipase was found among the groups. Group II had the highest scores of necrosis and acinar cell vacuolization, whereas group III had the highest scores of leukocyte infiltration and edema. The degree of necrosis was significantly more severe in group II than in group I. The hematocrit increased significantly in 5 hours in groups I and II. The mean arterial pressure in 5 hours decreased significantly in group I. There was no significant difference of the changes of heart rate in 5 hours among 3 groups. CONCLUSIONS: Intraductal infusion of NaTDC was a good method to induce moderate acute necrotizing pancreatitis in rats. GDOC caused mild pancreatitis, and pancreatic injury was aggravated when enterokinase was added. The severity of pancreatic histopathology was not correlated with the changes of serum levels of pancreatic enzymes, hematocrit or mean arterial pressure at the early stage of pancreatitis.

Acute Disease↗
PubMed1994

Effects of Ca2+ on the activation of conventional and new PKC isozymes and on TPA and endothelin-1 induced translocations of these isozymes in intact cells.

The effects of Ca2+ on the translocation of conventional and new protein kinase C isozymes in intact cells were studied by using C6 glioma cells as a model system. Two conditions which monitor intracellular Ca2+ were performed: one is extracellular Ca(2+)-depletion by treating the cells with physiological saline solution (PSS) without Ca2+ but containing 0.5 mM EGTA, the other is treating the cells with 1 microM ionomycin to induce Ca(2+)-influx. In addition, the TPA and endothelin-1 induced translocations of conventional and new PKC isozymes under these two conditions were also comparatively studied. When the intact cells were treated with Ca(2+)-free, EGTA containing PSS, the membrane-bound conventional PKC alpha (cPKC alpha) was greatly reduced and cytosolic cPKC alpha was slightly increased. However, neither membrane bound nor cytosolic new PKC delta (nPKC delta) was affected by extracellular Ca(2+)-depletion. On the other hand, when the cells were treated with 1 microM ionomycin, the translocation of cPKC alpha itself was observed while nPKC delta was not affected. In extracellular Ca(2+)-depletion, the translocation of cPKC alpha induced by 100 nM TPA still occurred although the extent of translocation was smaller than that induced by TPA under normal Ca2+ conditions; however, that induced by 30 nM ET-1 was blocked. After the cells were treated with 1 microM ionomycin, the translocation of cPKC alpha induced by 30 nM TPA was further increased compared to 1 microM ionomycin or 30 nM TPA alone, while that induced by ET-1 was only slightly further increased. All these results suggested that in intact cells, the activation of cPKC alpha was operated by both the intracellular Ca2+ level and diacylglycerol and that of nPKC delta was operated by diacylglycerol alone as predicted by their properties from purified enzyme or cDNA. In addition, the translocation of cPKC alpha induced by the natural activator ET-1 seemed to be more dependent on Ca2+ than TPA in intact cells.

Biological Transport↗
PubMed1994

Alterations of protein kinase C isozyme and substrate proteins in mouse brain after electroconvulsive seizures.

Protein kinase C (PKC) activity, Western blot analysis of PKC alpha, beta, gamma, epsilon and zeta with isozyme-specific antibodies, endogenous substrate protein phosphorylation, and Western blot analysis of neuromodulin, were studied in mouse brain after repeated electroconvulsive shock. The PKC isozymes and endogenous substrates in the crude cytosolic and membrane fractions were partially purified on DE-52 columns eluted with buffer containing 100 or 200 mM KCl. The kinase activity assayed by phosphorylation of exogenous histone was increased in the 200 mM KCl eluates of both the cytosol and membrane fractions from electroshocked mice. Further analysis by immunoblotting demonstrated that this increased activity was due to an increase in the PKC gamma isozyme. The level of the novel type isozymes, epsilon and zeta, was not altered in electroshocked mice. An in vitro phosphorylation study showed that the endogenous substrate, 17 kDa neurogranin, was mostly eluted by 100 mM KCl. In contrast, the 43 kDa neuromodulin only appeared in the 200 mM KCl eluate, according to autoradiography, SDS-PAGE and Western blot analysis; its level was found to be increased in the membrane fraction of electroshocked mice, as demonstrated by in vitro phosphorylation studies. Therefore, an increase in both PKC gamma and neuromodulin contributed to the increased phosphorylation of neuromodulin during electroshock seizure.

Animals↗