Tyrosine protein kinases in membrane fractions from rat cerebral cortex

Specific activities of tyrosine tubulin kinase in the particulate fractions from rat cerebellum, medulla oblongata, hypothalamus, striatum, midbrain, and cerebral cortex ranged within 30% of each other and more than 3 times higher than those in the soluble fractions. In the cerebral cortex, tyrosine protein kinase activity toward tubulin and tyrosine-glutamate (1:4) copolymers was mainly distributed in the plasma membrane and the microsome fractions. The kinase activity in cerebral cortex particulate fractions was quantitatively solubilized and separated into two peaks, kinase I and kinase II, by Sephacryl S-300 gel filtration in the presence of 0.2% Nonidet P-40 and 0.2 M NaCl. Kinases I and II were each resolved into 5 active peaks (I-1----5 and II-1----5) by casein-Sepharose column chromatography. The molecular weights of these kinases were estimated from the s20,w values to be 59,000-65,000. The Km values of II-1----5 for tubulin were nearly 10 times higher than those of I-1----5. However, the Km values of the two groups of kinases for tyrosine-glutamate copolymers were not so significantly different. About 60% of the copolymers kinase activity in I-3, I-4, II-3, and II-4 was immunoprecipitable with a saturating amount of monoclonal antibody against pp60c-src. Incubation of the immunoprecipitates with ATP resulted in the autophosphorylation of a 60 kDa protein in I-3 and I-4, and a 52 kDa protein in II-3 and II-4. Immunoblotting also indicated I-3 and I-4 as 60 kDa bands and II-3 and II-4 as 52 kDa bands on SDS-polyacrylamide gels.(ABSTRACT TRUNCATED AT 250 WORDS)

Potentiation of ethanol-induced pancreatic injury by dietary fat. Induction of chronic pancreatitis by alcohol in rats

Effects of sustained ethanol intoxication and dietary fat content on pancreatic morphology were investigated in the rat model implanted with gastrostomy catheters, which permitted continuous intragastric infusion of ethanol plus liquid diet containing one of three levels of corn oil: 5% (low-fat), 25% (high-fat), and 35% (extra-high-fat) of total calories. After various durations of infusion ranging from 30 to 160 days, the pancreatic histology was examined. Mean blood alcohol levels achieved in the low, high, and extra-high fat diet groups were similarly high: 210 +/- 120, 224 +/- 122, and 289 +/- 110 mg/dl. The average weight gain of these ethanol-fed groups during the first 8 weeks of experiments was 15.4 +/- 1.9, 19.6 +/- 8.0, and 14.9 +/- 5.2 g/wk, respectively, and was not statistically different from that of pair-fed controls infused with isocaloric amount of dextrose and respective diet, nor from that of age-matched animals given the regular chow. None of control animals showed abnormal pancreatic morphologic features except occasional mild steatosis in those fed the extra-high-fat diet. With the low dietary intake of unsaturated fat, chronic ethanol intoxication produced only mild pancreatic pathology such as steatosis and interstitial edema. Administration of ethanol and the high-fat and extra-high-fat diets caused hypogranulation and apoptosis of acinar cells. Focal lesions of chronic pancreatitis were also observed in 20% or 30% of ethanol-fed animals given the high-fat or extra-high-fat diet. These lesions were characterized by fat necrosis, mononuclear cell infiltration, fibrosis, acinar atrophy, ductal dilatation, and intraductal mucious or proteinacious plugs. The incidence of focal acute pancreatitis was less (7-20%) but appeared increased with higher dietary fat content. Induction of either acute or chronic pancreatitis was not correlated with plasma levels of triglycerides or cholesterol. These results demonstrate potentiation by dietary unsaturated fat of ethanol-induced pancreatic injury. This model possesses many features analogous to those seen in alcoholic pancreatic injury in man. The hyperlipidemia does not appear to be an important pathogenetic factor for ethanol-induced pancreatitis produced in this model.

Detection of myocardial reperfusion by analysis of serum creatine kinase isoforms

Serum creatine kinase (CK) MM isoforms were determined by chromatofocusing in 22 patients with acute myocardial infarction undergoing intracoronary thrombolysis. In 13 patients with successful coronary recanalization within 3.6 +/- 1.0 (SD) h after onset, time to peak CK activity occurred 13 +/- 3 h after onset which was significantly shorter (p less than 0.01) than that in 9 patients without coronary recanalization (20 +/- 4 h). The proportion of CK MM-A, the myocardial isoform, in serum in the reperfused group at 6, 10, and 14 h after onset (53 +/- 9, 38 +/- 5, and 27 +/- 4%, respectively) was always significantly lower (p less than 0.01) than that in the nonreperfused group (69 +/- 7, 59 +/- 8, and 43 +/- 4%). During the same period, the proportions of CK MM-B and CK MM-C, the converted isoforms derived intravascularly from MM-A by circulating carboxypeptidase, in the reperfused group were always significantly higher (p less than 0.01) than those in the nonreperfused group. The ratios of MM-A% to MM-B% and MM-A% to MM-C% amplified the differences between the two groups. At 10 h after onset, these ratios clearly differentiated the reperfused and the nonreperfused group at the values of 1.0 (MM-A/MM-B) and 3.0 (MM-A/MM-C) with the diagnostic sensitivity of 85% and 92%, respectively. Thus, myocardial reperfusion was detectable noninvasively by analysis of serum CK MM isoforms during the early stage of acute myocardial infarction.

[An autopsy case revealing bilateral successive testicular germ cell tumors of different cell types]

A 28-year-old man, evidencing a painless swelling of the right scrotal content, was admitted and, after a diagnosis of a right testicular tumor, a right high orchiectomy was performed. A histological examination of the right testicular tumor revealed a seminoma. Eleven months after this operation, the patient returned, complaining of a painful swelling of the left testis. An examination revealed that his alpha-fetoprotein (AFP) was elevated (3319 ng/ml). A left high orchiectomy was performed after he was diagnosed as a non-seminomatous tumor. Later, a histological examination revealed, however, an embryonal carcinoma. Two months after the second operation, a metastases of right supra-clavicular lymph nodes was uncovered and adjuvant chemotherapy was started. Although he died from the progression of this metastases, at autopsy, the retroperitoneal and para-aortic metastatic lymph nodes revealed a mature teratomatous and embryonal carcinoma.

Three distinct forms of type 2A protein phosphatase in human erythrocyte cytosol

Two type 2A protein phosphatases, phosphatases I (Mr = 180,000) and III (Mr = 177,000), were purified to near homogeneity from human erythrocyte cytosol. Phosphatase I was composed of alpha (34 kDa), beta (63 kDa), and delta (74 kDa) subunits in a ratio of 1:1:1. Phosphatase III comprised alpha, beta, and gamma (53 kDa) subunits in the same ratio. Heparin-Sepharose column chromatography converted most of phosphatase I and 20% of phosphatase III into alpha 1 beta 1 which were indistinguishable from phosphatase IV (Usui, H., Kinohara, N., Yoshikawa, K., Imazu, M., Imaoka, T., and Takeda, M. (1983) J. Biol. Chem. 258, 10455-10463). The catalytic subunit alpha and the beta subunit of phosphatases I, III, and IV displayed identical V8 and papain peptide maps, respectively, while the peptide maps of the alpha, beta, gamma, and delta subunits were clearly distinct. The molar ratio of phosphatases I, III, and IV in erythrocyte cytosol was estimated to be 6:1:14. Comparison of molecular activities of alpha, alpha 1 beta 1, alpha 1 beta 1 delta 1, and alpha 1 beta 1 gamma 1 revealed that beta suppressed phosphorylase and P-H2B histone phosphatase activities of alpha but stimulated the P-H1 histone phosphatase activity, and delta suppressed all the phosphatase activities of alpha 1 beta 1. The gamma subunit stimulated the P-histone phosphatase activity of alpha 1 beta 1 but inhibited the phosphorylase and P-spectrin phosphatase activities. The beta subunit increased the Mg2+ or Mn2+ requirement for P-H2B histone phosphatase activity of alpha, an effect which was counteracted by delta. The effects of heparin, H1 histone, protamine, and polylysine on the phosphorylase phosphatase activity of phosphatases I, III, IV, and alpha were described and discussed in connection with the functions of the subunits.

Lack of evidence for increased lipid peroxidation in ethanol-induced centrilobular necrosis of rat liver

The pathogenetic role of lipid peroxidation in ethanol-induced liver injury was previously supported by demonstration of increased formation of diene conjugates and decreased hepatic levels of reduced glutathione in ethanol-fed animals and alcoholic patients with liver injury. The present study was carried out to investigate whether these findings can be extended to a rat model that was shown to produce a spontaneous ethanol-induced liver injury progressing from steatosis to necrosis and fibrosis (Hepatology 6: 814, 1986). Despite the histological evidence of progression from hepatic steatosis to centrilobular necrosis in these animals, diene conjugate formation in mitochondrial and microsomal lipids was not enhanced when compared to pair-fed controls. In addition, hepatic levels of neither methionine nor glutathione were decreased in the ethanol-fed animals. The fatty acid composition of mitochondrial phospholipids from these animals was similar to that in the controls. However, in the microsomal phospholipids, the level of arachidonate (20:4) was depressed by about 50% as compared to the controls. These results demonstrate the lack of evidence for a pathogenetic relationship between lipid peroxidation and ethanol-induced liver injury progressing to centrilobular necrosis. They further suggest that the decreased levels of 20:4 commonly seen after chronic ethanol intake may not be due to a peroxidative loss.

[Susceptibility of clinical isolates to aztreonam]

Aztreonam (AZT), which has a newly developed and synthetic structure belonging to the group of monobactams, possesses excellent antibacterial activity against a broad range of Gram-negative bacteria (including the beta-lactamase producing strains). Antibacterial activities of AZT were examined and compared with those of 5 antibiotics (cefoperazone (CPZ), latamoxef (LMOX), cefotaxime (CTX), cefmetazole (CMZ) and cefsulodin (CFS) against 296 strains of clinical isolates. The evaluation of antibacterial activities was determined with the inhibition zone diameter obtained by the single disc method. The results can be summarized by three categories as follows: 1. Susceptibility of clinical isolates to AZT and other antibiotics AZT and other 3rd-generation antibiotics (CPZ, LMOX, CTX) showed excellent antibacterial activities against most strains. Especially AZT was more active against Enterobacter cloacae and Serratia marcescens than reference drugs. Against Pseudomonas aeruginosa, the activity of AZT was similar to that of CFS. AZT showed as excellent activity against P. aeruginosa as CFS. 2. Susceptibility of strains isolated from different clinical materials and different clinics AZT showed the highest antibacterial activity against the clinical isolates from sputum, pharynx, urine, pus, bile, puncture fluid, blood and others. AZT exhibited the most potent activity against isolates in the 7 clinics we tested. 3. Susceptibility of strains isolated from inpatients and outpatients AZT demonstrated the highest antibacterial activity (the rate of susceptibility: 87.0%) against strains obtained from inpatients (except for P. aeruginosa). The activity of AZT (81.4%) against P. aeruginosa was as active as that of CFS (81.4%), and it was the highest in all drugs. Antibacterial activity of these antibiotics against bacteria was rated as follows: AZT greater than LMOX greater than CPZ greater than CTX greater than CMZ AZT showed the highest antibacterial activity (100%) against strains isolated in all the materials and at all the clinics tested of outpatients. Antibacterial activity of these antibiotics against isolates from outpatients was rated as follows: AZT greater than CPZ greater than LMOX greater than CTX greater than CMZ.

Time dependent conversion of creatine kinase MM isoforms in man

Subforms of creatine kinase MM isoenzyme (isoforms, pI: MMA = 7.95, MMB = 7.76, MMC = 7.54) in human myocardium and serum were quantified by chromatofocusing. Creatine kinase MMA was a dominant isoform (greater than 94% of MM) in normal (n = 3) and in both infarcted and non-infarcted myocardium (n = 2). To investigate isoform conversion in vitro partially purified MMA was incubated with human plasma at 37 degrees C for 24 h (n = 5). Creatine kinase MMB (0%, 47%, 44% of MM at 0, 12, 24 h respectively) and MMC (0%, 22%, 42%) sequentially appeared in incubation media whereas MMA (100%, 31%, 14%) disappeared rapidly with a mean disappearance rate of -0.00169(0.00021)(SD) min-1. Individual differences in conversion velocity were small (SD less than 5%). To investigate isoform conversion in vivo serum isoforms were analysed in patients with acute myocardial infarction (n = 7). MMA was first dominant (A:B:C = 54:34:12%) in the early stage (6-9 h after the onset of chest pain) followed by MMB dominant (19:42:39%) in the middle stage (24-35 h), and MMC dominant (6:22:72%) in the late stage (54-60 h). Changes in isoform proportion were time dependent regardless of serum creatine kinase activity. These findings are consistent with canine isoform conversion reported previously except that in man the velocity of conversion was slower than in the dog. Thus analysis of serum creatine kinase MM isoforms may allow the onset of acute myocardial infarction to be precisely dated. Moreover, determination of MMA, the isoform native to myocardium with a short serum half life, may be useful in the prompt diagnosis of myocardial infarction.

Ethanol-induced hepatic fibrosis in the rat: role of the amount of dietary fat

We have made a comparison between groups of rats fed ethanol and a diet that received intragastric infusion of ethanol continuously for prolonged periods varying only in the amount of fat in the diet (percentage of total calories as fat was 5, 25, and 35%). A fourth group of rats fed high fat (32% of calories) and a diet marginal in protein, vitamins and minerals was also studied. Control rats were pair-fed dextrose in isocaloric amounts. For rats fed diets containing 5, 25, 32, and 35% fat, the average blood alcohol levels achieved were 216, 224, 266 and 353 mg/100 ml, respectively. Average weight gains of the ethanol fed rats were: 15.4, 19.6, 14.7, and 14.9 g/week, respectively. Serum alanine aminotransferase (ALT) levels of the ethanol-fed rats averaged 123, 292, 144, and 213 units/liter, respectively. ALT levels in pair-fed controls for the rats fed 32% fat averaged 62 and those of chow-fed controls averaged 49 units/liter. Comparison of liver biopsy-semiquantified morphological findings revealed an increased 3-4+ fatty change in the ethanol-fed rats also fed the high fat rats. Moreover, fibrosis was only observed centrilobularly in rats fed diets with varying fat content (5, 25, 32, or 35% of calories): 0/16, 10/17, 4/6, and 3/7 rats, respectively, over a 5-mon period of feeding. Electron microscopy showed that ito cells predominated in the scarred areas. The mechanism for the centrilobular necrosis-fibrosis was investigated in rats given a diet of ethanol plus 32% fat diet by measuring the level of adenine nucleotide in repeated liver biopsies in five pair of rats.(ABSTRACT TRUNCATED AT 250 WORDS)

Increased pancreatic acinar content and secretion of cationic trypsinogen following 30-day continuous ethanol intoxication in rats

The effects of sustained, high blood alcohol levels (216 +/- 120 mg/100 ml, S.D.) for 30 days on cholecystokinin (CCK)-mediated pancreatic exocrine function were studied in a rat model that achieves both maximally controlled, optimal nutrition and high alcohol intake (approximately 40.5% of total calories). In alcohol-fed rats, basal plasma levels of immunoreactive cationic trypsinogen (ICT) were reduced by 50% (P less than 0.05), but intravenous doses (0-30 IDU/kg/hr; 1 IDU = approximately 62.5 ng CCK-8) of cholecystokinin octapeptide (CCK-8) resulted in a 3-fold greater maximal concentration of ICT and an 80% steeper slope of the dose-response curve compared to those of pair-fed control animals. Basal plasma levels of amylase were not different in the two groups at basal conditions and did not change significantly following CCK-8 administration. In vitro studies with isolated pancreatic acini have shown that basal secretion of ICT into the media was similar in the two groups. However, ICT secretion in response to CCK-8 (30-3000 pM) was 2-fold greater in alcohol-fed rats than in pair-fed controls, resulting in a CCK-8 EC50 which was about half that of controls. On the contrary, the basal and maximal amylase secretion from acini isolated from alcohol-fed rats was reduced by 67 and 43%, respectively, causing a reduction in the magnitude of the response curve with almost identical EC50 and slopes. Despite the marked alterations in CCK-stimulated enzyme secretion, radioiodinated CCK-33 binding to receptors on acini isolated from both control and alcohol-fed rats was similar. Cellular concentrations of ICT and amylase, however, revealed similar patterns of alterations: 2 to 3-fold increase in ICT and 70% reduction in amylase in alcoholic acini compared to controls. These results indicate that the inverse changes in amylase and ICT secretions following continuous ethanol administration are probably due to differential effects on enzyme synthesis.

Immunoenzymometric determination of trypsin/alpha 1-protease inhibitor complex in plasma of rats with experimental pancreatitis

The currently available radioimmunoassays of trypsin measure total immunoreactive trypsin (EC 3.1.1.7), which includes both trypsinogen and alpha 1-protease inhibitor-bound trypsin. Hitherto, the only way to differentiate these two forms of trypsin has been to fractionate them on a gel-filtration column. We describe here a solid-phase immunoenzymometric assay that rapidly measures the amount of cationic trypsin bound to alpha 1-protease inhibitor in the plasma of rats with experimental pancreatitis. The assay specifically measures this complex within the range from 0.2 to 5.0 ng without interference by high concentrations of free alpha 1-protease inhibitor. The high correlation (r = 0.985) of the values obtained by size fractionation and by this assay demonstrates the accuracy of the assay, which is the first single-tube method for determining this form of activated cationic trypsin in plasma.

Correlation of trypsin-plasma inhibitor complexes with mortality in experimental pancreatitis in rats

Activation of trypsinogen in acute pancreatitis results in subsequent increases in plasma levels of trypsin bound to the inhibitors alpha 1-protease inhibitor (alpha 1-PI) and alpha-macroglobulin (alpha-M). It seems logical to speculate that plasma levels of these inhibitor-bound forms of trypsin may reflect the degree of intrapancreatic zymogen activation and that determination of such parameters may be of diagnostic and prognostic value. In order to test this hypothesis, the concentrations of trypsinogen and of trypsin bound to alpha 1-PI have been determined in serial plasma samples from rats who died (N = 7) and survived (N = 5) following induction of pancreatitis with taurocholate. Since the other major reaction product of active trypsin in plasma, alpha-macroglobulin-bound trypsin, cannot be measured directly, the plasma levels of trypsin-like amidase activity were determined to estimate the concentration of trypsin-alpha-M complex. Shortly after induction of pancreatitis, elevated levels of trypsinogen were present in plasma, but no alpha 1-PI-bound trypsin could be detected. Trypsin-alpha 1-PI complex continuously increased over the time course of pancreatitis in animals that died. In contrast, the plasma levels of trypsin-alpha 1-PI complex were lower in animals that survived, peaked around 15 hr postinduction at levels (182 +/- 53 ng/ml) significantly lower than those in dying animals (543 +/- 346 ng/ml), and fell during the following 48 hr. There was a significant correlation between plasma trypsin-like amidase activity and plasma alpha 1-PI-bound trypsin. Our data demonstrate that the concentration of activated forms of plasma trypsin in the bloodstream are correlated with mortality in experimental pancreatitis.

Immunoenzymometric determination of trypsin/alpha 1-protease inhibitor complex in plasma of rats with experimental pancreatitis

The currently available radioimmunoassays of trypsin measure total immunoreactive trypsin (EC 3.1.1.7), which includes both trypsinogen and alpha 1-protease inhibitor-bound trypsin. Hitherto, the only way to differentiate these two forms of trypsin has been to fractionate them on a gel-filtration column. We describe here a solid-phase immunoenzymometric assay that rapidly measures the amount of cationic trypsin bound to alpha 1-protease inhibitor in the plasma of rats with experimental pancreatitis. The assay specifically measures this complex within the range from 0.2 to 5.0 ng without interference by high concentrations of free alpha 1-protease inhibitor. The high correlation (r = 0.985) of the values obtained by size fractionation and by this assay demonstrates the accuracy of the assay, which is the first single-tube method for determining this form of activated cationic trypsin in plasma.

Ethanol-induced liver fibrosis in rats fed high fat diet

Severe hepatic steatosis and focal necrosis of hepatocytes have previously been induced in rats by continuous intragastric infusion of ethanol and a diet containing only 5% fat as a per cent of total calories as reported by us previously. Since the ethanol diet fed ad libitum with such a low level of fat has previously failed to produce alcoholic fatty liver, continuously high blood alcohol levels achieved in this model appeared to be key in induction of the progressive pathologic lesions in the liver. In the current study, effects of increased fat intake on alcohol-induced liver injury were investigated. Seventeen pairs of male Wistar rats were implanted with gastrostomy cannulas and infused with a liquid diet containing 25% of total calories as fat plus ethanol or isocaloric dextrose. Ethanol intake was progressively increased from 32% up to 47% of total calories to maintain sustained intoxication for 30 to 120 days. Light and electron microscopic examination of the liver revealed moderate to severe fatty infiltration in all of the ethanol-fed rats, of which 14 had spotty or zonal necrosis in the centrilobular areas accompanied by polymorphonuclear and mononuclear cell infiltration. In addition, fibrosis was observed in association with the necrotic lesions or with large-droplet steatosis. Reticulin and trichrome stains clearly demonstrated fine fibrosis, including perivenular fibrosis as well as septum formation progressing to bridging fibrosis. Furthermore, increased numbers of Ito cells and myofibroblasts were observed in the perivenular fibrotic areas. These results demonstrate striking potentiation of alcohol-induced liver injury by the increased fat intake or by the concomitant decrease in carbohydrate intake.(ABSTRACT TRUNCATED AT 250 WORDS)

Effects of cholecystokinin, food intake and cephalic stimuli on plasma levels of amylase, lipase, and immunoreactive cationic trypsinogen in rats

Plasma levels of amylase, lipase, and immunoreactive cationic trypsinogen (ICT) were monitored in conscious rats to study the effects of cholecystokinin octapeptide (CCK-8) plus secretin administration, cephalic stimuli, and food intake. Stepwise increasing doses of CCK-8 (1, 5, 15, 30 Ivy dog units: IDU/kg/h) caused significant dose-related increases in plasma levels of each enzyme in a similar manner as those previously observed for response patterns of CCK-induced exocrine protein secretion in the same species. ICT showed the greatest response to CCK-8 with a maximal concentration 30 times above basal levels resulting in the steepest slope of the dose-response curve. Plasma lipase showed a maximal response that was 5 times above the basal level, while the plasma amylase level was increased only by 50% at the maximal response. Computed ED50 of CCK-8 for each enzyme confirmed this relative sensitivity of the response: 3.0, 8.7, 11.0 IDU/kg/h for ICT, lipase, and amylase, respectively. Plasma levels of amylase and lipase did not change significantly in response to the intake of either a liquid diet or fiber pellets containing no caloric value. Plasma ICT levels, however, were elevated significantly by 23 and 53% at the time when the liquid diet or fiber pellets were given and when cephalic stimulation appeared maximally induced. The increased levels declined thereafter and were no longer significantly different from the basal levels for postprandial 2 h.(ABSTRACT TRUNCATED AT 250 WORDS)

Comparison of tyrosine protein kinases in membrane fractions from mouse liver and Ehrlich ascites tumor

Tubulin was phosphorylated mainly at tyrosine residues by membranes from mouse liver and Ehrlich ascites tumor with ATP in the presence of MnCl2, ZnCl2, NaVO3, and Nonidet P-40 in an epidermal growth factor (EGF)- and insulin-independent manner. The tyrosine tubulin kinase activity in the tumor membranes is comparable to the activity in liver membranes. Two tyrosine tubulin kinases, namely I (Mr = 64,000) and II (Mr = 46,000), were purified 5-17-fold and were free of the EGF receptor and the insulin receptor. Phosphorylation of endogenous proteins produced major alkali-resistant phosphoproteins of 56 and 53 kDa in kinase I preparations and of 46 and 37 kDa in kinase II preparations. These kinases phosphorylated tubulin stoichiometrically at tyrosine and had a preference of alpha-subunit to beta-subunit of tubulin. Apparent Km values of kinases I and II for tubulin were about 4 and 8 microM and for ATP were about 2 and 4 microM, respectively. Thiol reagents inhibited their reactions. N alpha-p-Tosyl-L-lysine chloromethyl ketone stimulated the reactions at 1 mM but inhibited them at 5 mM. Although kinases I and II also phosphorylated angiotensin II, tyrosine-glutamate copolymers, and heavy chains of anti-pp60src IgG, they differed from each other in preferences for the substrates. More than 95% of the enzyme activities was not immunoprecipitated with the anti-pp60src IgG which cross-reacts with pp60c-src. In comparison with the corresponding liver enzymes, tumor enzymes were more stable to heat and incorporated more phosphate into tubulin, but showed lower activity toward angiotensin II and anti-pp60src IgG.