Lack of α2-Antiplasmin Enhances ADP Induced Platelet Micro-Aggregation through the Presence of Excess Active Plasmin in Mice

Background: The role of 2-antiplasmin (2-AP) on platelet aggregation was investigated using mice deficient in 2-AP (2-AP^–/–) or using wild type mice (2-AP^+/+). Methods: Blood samples were taken from each mouse under anesthesia with ether and platelet rich plasma (PRP) was prepared. Platelet aggregation induced by various doses of ADP (0.3–30 M) was detected using a laser-light scattering (LS) system. Aggregated forms were observed using a scanning electron microscopy (SEM). Results: Dose-dependent platelet aggregation was not different in both types of mice. However, platelet micro-aggregate formation in 2-AP^–/– mice induced by low dose of ADP (1.0 M) markedly increased compared to the situation in wild type mice. Aggregated form detected by SEM showed supported data from LS analysis. When washed platelets of 2-AP^+/+ mice were resuspended in plasma of 2-AP^–/– mice, platelet micro-aggregation was also increased. On the contrary, when washed platelets of 2-AP^–/– mice were suspended in plasma of 2-AP^+/+ mice, platelet micro-aggregation did not change. In separate experiments, tPA (1.0 g/ml) was added to PRP before the stimulation of ADP. tPA had no effect on platelet aggregation in 2-AP^+/+ mice, however platelet micro-aggregation in 2-AP^–/– mice was markedly increased by the treatment with tPA. Moreover, the amount of released ATP from stimulated platelets was increased in 2-AP^–/– mice treated with tPA. Conclusion: Lack of 2-AP increased platelet micro-aggregation, and plasmin plays an important role in the formation of platelet aggregation when 2-AP knockout mice are used. Consequently, the reduction of 2-AP could be a risk factor for the activation of platelets resulting in thrombus formation.     

Glucokinase is not the pancreatic B-cell glucoreceptor

Summary A series of recent experimental findings are reviewed to indicate that glucokinase does not represent the pancreatic B-cell glucoreceptor. (1) Whether in liver, pancreatic islet or insulin-producing tumoral cell homogenates, glucokinase fails to yield a higher reaction velocity with -than -D-glucose. (2) At a high glucose concentration (40 mmol/l), when the phosphorylation of glucose by glucokinase is indeed higher with - than -D-glucose, no preference for -D-glucose is observed in intact islets, as judged from the utilization of D-[5-³H]glucose, production of lactic acid, oxidation of D-[U-¹⁴C] glucose, net uptake of ⁴⁵Ca or release of insulin. (3) The glucose 6-phosphate content of intact islets is higher in the presence of - than -D-glucose. (4) At a low glucose concentration (3.3 mmol/l), when the participation of glucokinase to hexose phosphorylation is minimal, -D-glucose is still better metabolized and stimulates both ⁴⁵Ca net uptake and insulin release more efficiently than -D-glucose, despite the fact that hexokinase yields a higher reaction velocity with - than -D-glucose. (5) In intact islets, -D-glucose is used preferentially to -D-glucose in the pentose cycle pathway as judged from the oxidation of - or -D-[1-¹⁴C]glucose relative to that of - or -D-[6-¹⁴C]glucose. (6) In islets removed from fasted rats, the rate of glycolysis is more severely decreased than expected from the repression of glucokinase. (7) The metabolism of glucose in tumoral insulin-producing cells differs, in several respects, from that in normal pancreatic islets, although the pattern of hexokinase and glucokinase activities is similar in these two types of cells. All these observations point to the participation of regulatory sites distal to glucose phosphorylation in the control of glucose metabolism in islet cells.     

Expression and prognostic roles of integrins and interleukin-1 receptor type I in patients with ductal adenocarcinoma of the pancreas

To Investigate the prognostic indicator, we examined the expression of ₆- and ₅- integrin and interleukin-1 receptor type I (IL-1RI) immunohistochemically, and analyzed the correlation between immunohistochemical findings and clinicopathological factors in pancreatic cancer. In patients with a strongly expressing ₆- integrin subunit or weakly expressing ₅₁-integrin in pancreatic cancer tissues there was a significant association with advanced TNM stage (P = 0.027 and 0.014, respectively), presence of liver metastases (P = 0.032 and 0.002, respectively), and poor prognosis (P = 0.0155 and 0.0056, respectively). In patients with a weakly expressing ₆ integrin subunit or weakly expressing ₅₁-integrin in noncancerous pancreatic tissues there was a significant association with poor prognosis (P = 0.0324 and 0.0396, respectively). Multivariate analysis demonstrated that strong expression of ₆- and weak expression of ₅₁-integrin were found to be independent prognosticators in pancreatic cancer patients. Our present results indicate that ₆₁- and ₅₁-integrin expression can be a significant prognostic indicator in pancreatic cancer.     

Preservation of the anomeric specificity of glucose-induced insulin release in partially pancreatectomized rats

Summary Attenuation, suppression or even inversion of the normal preference of glucose-stimulated insulin release for the -anomer of the hexose was recently proposed to represent a feature of Beta-cell glucotoxicity in Type 2 (non-insulin-dependent) diabetes mellitus. Since recent reports emphasize the possible significance of Beta-cell secretory hyperactivity as a determinant of such a glucotoxicity, the anomeric specificity of glucose-induced insulin release was examined in normoglycaemic partially pancreatectomized rats. About 80–85% of the pancreas was removed, the animals then being given sucrose via their drinking water up to the time of killing. In these animals, -D-glucose was more efficient than -D-glucose in stimulating insulin release from the perfused pancreas, the / ratio in insulin output not being significantly different from that found in control rats. It is concluded, therefore, that the anomeric malaise, taken as a manifestation of Beta-cell glucotoxicity, it attributable to hyperglycaemia rather than to Beta-cell secretory hyperactivity.     

α1-antitrypsin deficiency and liver disease

Summary ₁-Antitrypsin (₁AT) deficiency, one of the most common lethal hereditary disorders among Caucasians, is associated with emphysema in adults, while in children it is associated with liver disease. Produced in the liver and released into the plasma, ₁AT serves as the body's major inhibitor of neutrophil elastase, a powerful proteolytic enzyme capable of degrading extracellular structural proteins. The pathogenesis of the liver disease associated with ₁AT deficiency is not as well understood, but is clearly linked to specific mutations in coding exons of the ₁AT gene, and the resulting accumulation of ₁AT within hepatocytes. At present, therapy for the liver disease associated with ₁AT deficiency is symptomatic, with liver transplantation as a last resort. New strategies are being developed to suppress the accumulation of ₁AT by transferring the normal gene into the liver.     

The effects of parabiosis on serum and kidney glycosidase activities in spontaneously diabetic mice

Summary Spontaneously diabetic non-obese mice of the ICR strain were newly inbred in Shionogi laboratory, Japan. Animals became diabetic suddenly, more frequently and severely in females. Blood glucose levels were 452±73 mg/100 ml with serum insulin levels of < 1.0 U/ml in the fed state. Parabiosis with normal control ICR mice for 2 weeks decreased the blood glucose level to 260±51 mg/ 100ml (P<0.01) and resulted in serum insulin levels of 46.0±18.0 U/ml (P<0.01). Kidney homogenate -N-acetylglucosaminidase and -galactosidase activities were reduced in diabetic mice (42% and 44% decrease respectively) (P<0.025 and P<0.001), and restored almost to normal after 2 weeks of parabiosis. Renal -mannosidase activity was decreased 43% (P<0.001) in the diabetic mice but unaffected by parabiosis. Serum -N-acetylglucosaminidase, -galactosidase and -glucosidase activities were significantly increased in diabetic mice (179%; 233% and 58% increase respectively) (P<0.005, P<0.001 and P<0.001), and returned to normal with parabiosis.     

Enzymatic determination of serum 3α-sulfated bile acids concentration with bile acid 3α-sulfate sulfohydrolase

A newly developed enzymatic method for determining urinary 3-sulfated bile acids was used to measure serum 3-sulfated bile acid levels in 114 patients with hepatobiliary diseases and 56 healthy subjects. The lowest measurable amount of the 3-sulfated bile acids was 0.5 µmol/liter. The standard curves for glycolithocholic acid 3-sulfate, glycoursodeoxycholic acid 3-sulfate, and lithocholic acid 3-sulfate were linear from 0.5 to 250 µmol/liter. Specificity of the assay was satisfactory and intra- and interassay variations ranged from 0.8 to 4.4% and from 1.2 to 7.9%, respectively. Analytical recovery was more than 91%. The values obtained by this assay were well correlated with those by gas-liquid chromatography measurement (r=0.91,P<0.01). The fasting serum 3-sulfated bile acids level in healthy subjects ranged from undetectable to 1.9 µmol/liter (mean±se; 0.9±0.1 µmol/liter). The percentage of 3-sulfated bile acids in total bile acids (sum of 3-sulfated and 3-hydroxy bile acids) in serum was 16.8±1.5%. In subjects with hepatobiliary diseases, serum 3-sulfated bile acids levels were elevated; however, the percentage of 3-sulfated bile acids in total bile acids was decreased and correlated with the severity of hepatocellular insufficiency. This enzymatic assay is simple, rapid, and accurate for the determination of serum 3-sulfated bile acids.     

Production of interleukin-1β and tumour necrosis factor-α in patients with benign or malignant ovarian tumours

Summary To assess the role of interleukin-1 (IL-1) and tumour necrosis factor (TNF) in the physiological host defence mechanisms against malignancies, the production of these cytokines in sera, ascitic and cyst fluids and in the tumour tissues of patients with benign or malignant ovarian tumours was studied. IL-1 was found neither in the sera nor in the ascitic fluids of these patients. It was also virtually absent from the cyst fluid samples. However, a mean value of 790 pg IL-1/g tumour was found. Like IL-1, TNF was virtually absent in the serum samples. It was, however, detectable in the ascitic and cyst fluids and tumour tissues. The TNF concentrations were highest in the tumour tissues, with a mean level of 328 pg/g tumour. When comparing the level of IL-1 and TNF in patients with benign tumours to that seen in patients with malignant tumours, no differences in production were observed, regardless of the origin of the test samples. Our results indicate the production of IL-1 and TNF in patients with ovarian tumours. More importantly, the finding that the production of these cytokines in patients with benign tumours is similar to that in patients with malignant tumours supports the conclusion that the production of these cytokines is more a nonspecific indicator of an inflammatory process than a specific response to a malignant process.Abbreviations IL interleukin - TNF tumour necrosis factor     

Lysosomal enzyme activities in serum and leukocytes from patients with carbohydrate-deficient glycoprotein syndrome type IA (phosphomannomutase deficiency)

From 10 patients with carbohydrate-deficient glycoprotein (CDG) syndrome due to phosphomannomutase (PMM) deficiency, out of 10 lysosomal enzymes, 7 enzyme activities were measured in serum and 9 in leukocytes. In serum there was a 2-fold to 4-fold increase in activity of -glucuronidase, -hexosaminidase, -galactosidase, and arylsulphatase A. In leukocytes, however, several enzymes had reduced activity, particularly -fucosidase, -glucuronidase and -mannosidase. These abnormalities could result from missorting, defective reuptake and/or reduced stability of the enzymes due to the defective glycosylation.     

Niemann–Pick disease type C and defective peroxisomal β-oxidation of branched-chain substrates

An 18-month-old infant presented with hypotonia, motor delay, hepatosplenomegaly, rickets and steatorrhoea. Biochemical investigations revealed typical features of Niemann–Pick disease type C. In addition, there was evidence of defective peroxisomal -oxidation of branched-chain substrates (3,7,12-trihydroxycholestanoic acid and pristanic acid). The steatorrhoea and fat-soluble vitamin malabsorption responded well to bile acid therapy. Possible causes for the double defect are considered.     

Serum zinc and copper in active rheumatoid arthritis: Correlation with interleukin 1β and tumour necrosis factor α

Serum zinc and copper levels and serum interleukin 1 (IL1) and tumour necrosis factor (TNF) levels were evaluated in 57 female patients with active rheumatoid arthritis (RA) to investigate a possible role of IL1 and TNF on zinc and copper homeostasis in RA. Serum zinc levels were significantly lower and serum copper levels significantly higher in RA patients when compared with osteoarthritis or asymmetrical psoriatic oligoarthritis patients and with normal controls. No differences were observed in serum IgM rheumatoid factor positive and serum IgM rheumatoid factor negative patients as regards serum zinc and copper concentration. In RA patients the erythrocyte sedimentation rate and acute-phase proteins correlated negatively with serum zinc and positively with serum copper. IL1 and TNF were found to correlate negatively with zinc and positively with copper in RA patients. Lower levels of zinc may be due to an accumulation of zinc-containing proteins in the liver and in the inflamed joints in RA. Elevated serum copper levels seem to be linked to the increased synthesis of ceruloplasmin by the liver.     

Calcium channel blocker treatment of tumor cells induces alterations in the cytoskeleton,mobility of the integrin αIIbβ3 and tumor-cell-induced platelet aggregation

Summary Calcium channel blockers of the phenylalkylamine (i.e. verapamil), benzothiazepine (i.e. diltiazem) and dihydropyridine (i.e. nifedipine) classes were evaluated for effects on the tumor cell/platelet interactions using Walker 256 carcinosarcoma cells (W256 cells). When W256 cells were pretreated for 15 min with channel blockers at concentrations of 50–200 M, macroscopic tumor-cell-induced platelet aggregation was inhibited (order of potency; nifedipine>diltiazemverapamil). However, ultrastructural analysis revealed limited, focal platelet aggregates associated with tumor cell plasma membranes of verapamil- and diltiazem-treated cells. There was no evidence of platelet activation or platelet association with the tumor cell membrane in cells pretreated with nifedipine. Walker 256 cells possess the integrin _IIb3. Tumor cell _IIb3 was shown to mediate tumor cell/platelet interactions in vitro [Chopra et al. (1988) Cancer Res. 48:3787]. Patching and capping of surface _IIb3 were inhibited by nifedipine>diltiazemverapamil. The degree of inhibition of _IIb3 receptor mobility parallels the inhibition of tumor-cell-induced platelet aggregation. W256 cells are characterized by a well-developed microfilament and intermediate filament network and by the absence of a distinct microtubular network. Calcium channel blockers had no effect on the low polymerization level of tubulin. However, they induced rearrangement of microfilament stress fibers. Intermediate filaments were also rearranged but to varying degrees. The order of effectiveness for alteration of intermediate filament organization was nifedipine>diltiazem while verapamil was ineffective. We propose that the previously reported inhibition of tumor cell/platelet interaction and tumor cell metastasis by calcium channel blockers [Honn et al. (1984) Clin Exp Metastasis 1:61] is due not only to the effects of the Ca²⁺ channel blockers on platelets, but also to their effect on the tumor cell cytoskeleton resulting in an inhibition of the mobility and function of the _IIb3 receptor.Abbreviations CCB calcium channel blocker - _IIb3 platelet glycoprotein IIb/IIIa complex - TCIPA tumor cell induced platelet aggregation - W256 Walker 256 carcinosarcoma This work was supported by Public Health Service grant CA-47115, a grant from Harper Hospital and a grant from the Veterans Administration     

Triplication (/ααα<Superscript>Anti3.7</Superscript>) or deletion (-α<Superscript>3.7</Superscript>/) association in Argentinian β-thalassemic carriers

Prevalence of alpha gene triplication or deletion in -thalassemia carriers was studied in 109 unrelated individuals in Rosario, Argentina. In different populations -^3.7 allele presents a higher prevalence than ^anti3.7; thus, -thalassemia associated with -thalassemia is more frequently observed. Nevertheless, this event was detected in only one case (0.9%), while the association with alpha triplication was present in two subjects (1.8%).     

Uptake and metabolism of radiolabelled GM1-ganglioside in skin fibroblasts from controls and patients with GM1-gangliosidosis

Summary The uptake and metabolism of [3-³H-sphingosine]GM1-ganglioside was measured in cultured skin fibroblasts from controls and patients with infantile, juvenile and adult GM1-gangliosidosis. When dissolved in medium with phosphatidylserine, GM1-ganglioside was efficiently taken up by cultured skin fibroblasts and transferred into lysosomes. A linear increase in GM1-ganglioside endocytosis was shown with phosphatidylserine concentrations of up to 40m/ml. A pulse-chase study revealed that [³H]GM1-ganglioside was metabolized to GM2-ganglioside, GM3-ganglioside, ceramide dihexoside, ceramide monohexoside, ceramide and sphingosine. Sphingosine was recycled to sphingomyelin. In a 20-h pulse study, cell lines from patients with GM1-gangliosidosis of infantile, juvenile and adult types hydrolysed 2–5%, 20–44% and 54–58% of the total endocytosed GM1-ganglioside respectively. These values were lower than in control cells (64.17 ± 5.43% (n=10)). The hydrolysis rates of exogenous [³H]GM1-ganglioside in cultured fibroblasts from patients with various types of GM1-gangliosidosis closely reflected the clinical severity.Abbreviations GM1 Gal13GalNAc14(NeuAc23)Gal14Galc-1-ceramide - GM2 GalNAc14(NeuAc23)Gal14Glc-1-ceramide - GM3 NeuAc23Gal14Glc-1-ceramide - CDH Gal14Glc-1-ceramide     

Modulation of IL-1β, IL-6, IL-8, TNF-α, and TGF-β secretions by alveolar macrophages under NO2 exposure

Activated alveolar macrophages (AMs) secrete interleukine (IL)1, IL-6, IL-8, tumor necrosis factor- (TNF-), and transforming growth factor- (TGF-), whose inflammatory and fibroblast-activating characteristics may play a role in the maintenance of pulmonary inflammatory processes and subsequent fibrosis. Human AMs were transferred to a gas cylinder and exposed to NO₂ in concentrations ranging from 0.1 to 0.5 ppm in synthetic air for 30 min at 37°C. AMs were fixed on a polycarbonate membrane and placed on culture medium. A culture was established, with the exposed AM (nonstimulated or stimulated with 1 g/ml lipopolysaccharide [LPS]), and the remaining cells were used to determine the cytokines. IL-1, IL-6, and IL-8 were quantified by commercial enzyme-linked immunosorbent assay kits (ELISA kits). TNF- was determined with a sandwich ELISA, using the biotin-streptavidin system. NO₂ exposure of nonstimulated AM did not result in changes in IL-1, IL-6, TNF-, and TGF- release, compared to the situation with control experiments. Exposure for 30 min to NO₂ induced a significant decrease of LPS-stimulated IL-1, IL-6, IL-8, and TNF- (p < .05). The release of TGF- was not significantly affected by NO₂ exposure. Cytotoxicity of AM was checked by trypan blue exclusion, with values ranging from 1.3 to 3.0%. NO₂ exposure of LPS-stimulated AM resulted in a functional impairment of AM after NO₂ exposure regarding IL-1, IL-6, IL-8, and TNF-. Neither the spontaneous nor the stimulated release of TGF- were influenced by NO₂.     

Distribution pattern of α and β myosin in normal and diseased human ventricular myocardium

Summary All fibers in three normal, four dilated, and two ischemic human ventricles were classified according to their myosin content using three sets of monoclonal antibodies each specific for one myosin heavy chain isoform (, and ). Numerous fibers contained only myosin heavy chain (denoted as fibers), others contained either and , or and myosin heavy chain (denoted as and fibers, respectively). The percentages of fibers were systematically determined along the walls of seven homologous regions of the ventricular myocardium.In all ventricles, there was an -fiber transmural gradient, with less fiber in the subendocardium than in the subepicardium. More fibers were found in the right than in the left ventricular wall but there was no difference between the mid-portion and the apex of the free wall of each ventricle. The diseased ventricles contained a lower fiber percentage than the normal hearts. fibers were very rare in the normal ventricles (less than 5%) and almost inexistent in pathological hearts. The correlation between the mean fiber percentages of the diseased hearts and their cardiac indices (r=0.88, P<0.05) suggests that the small amount of myosin distributed in a large number of ventricular fibers could play a role in the contractile performance of the heart. In conclusion, this study provides evidence for 1) an fiber transmural gradient, and 2) a lower myosin ratio in discased than in normal human ventricle.This work was supported in part by L'Institut National de la Santé et de la Recherche Médicale 101 rue de Tolbiac, 75013 Paris     

Comparative and combined effects of transforming growth factors α and β, interleukin-1 and interferon-γ on rheumatoid synovial cell proliferation,glycolysis and prostaglandin E production

Summary Enhanced cell proliferation, glycolysis and prostaglandin E production are all characteristic features of rheumatoid synovial tissue. The interrelationships of these three cellular parameters have been examined using rheumatoid synovial fibroblasts and their responses to specific cytokines in vitro. Transforming growth factor (TGF) caused a more than threefold increase in synovial cell proliferation whilst transforming growth factor (TGF), interleukin-1 (IL-1) and interferon- (IFN-) produced only marginal changes. The combined addition of IL-1 with TGF resulted in an enhanced proliferative response comparable with that produced by TGF. Glycolysis, estimated by glucose utilisation and measurements of the glycolytic regulatory metabolite fructose 2,6-bisphosphate was significantly stimulated by TGF, IL-1 and IFN-, but less so by TGF. Prostaglandin E production was significantly increased by IL-1 to an extent much greater than that produced by TGF or TGF, although the combined addition of IL-1 with either TGF or resulted in a synergistic increase in PGE production, a response partly diminished by the addition of IFN-. These findings suggest that the extent to which a cytokine stimulates glycolysis is not consistently related to its mitogenicity, and that cytokine combinations which stimulate high levels of PGE production (a growth inhibitor) will not necessarily be associated with a reduced rate of cellular proliferation in cultured, adherent, rheumatoid synovial fibroblasts.     

Appearance of a functional insulin receptor during rabbit embryogenesis

Summary The domain structure of the insulin receptor was investigated in liver and brown adipose tissue of developing rabbits. The structure of the binding domain (-subunit) was analysed after covalent labelling with a ¹²⁵I photo-reactive insulin analogue. The structure of the tyrosine kinase domain (-subunit) and the transmission of the hormonal signal from the -to the -subunit were analysed by stimulating with insulin the autophosphorylation of the -subunit. Finally, the immunoreactivity of the receptor in developing tissues was assessed with anti-receptor antibodies. The results show that a functional insulin receptor can be detected at the early stages of fetal development in both tissues and is conserved throughout ontogenesis to adulthood.     

Transforming Growth Factor-Alpha (TGF-alpha) Levels in Human Proximal Gastrointestinal Epithelium (Effect of Mucosal Injury and Acid Inhibition)

TGF- inhibits gastric acid secretion andmay play an important role in epithelial repair. Wequantitated regional levels of TGF- in the humanproximal gastrointestinal tract and determined whether they are affected by acid suppression oraspirin-induced injury. Ten healthy volunteers werestudied. After baseline endoscopy with biopsy, fiverandomly received no treatment, aspirin, omeprazole, orcimetidine for one week. Endoscopy was repeated and priorunhealed biopsy sites quantitated. TGF- levelswere measured by RIA. Five additional subjects thencompleted an extended protocol of three weeks' duration. All subjects were free of H. pylori infection.TGF- levels in the antrum, 34.76 ± 5.54 pgTGF-/g DNA were threefold higher than in thegastric body and duodenum (11.03 ± 2.60 and 10.41± 1.64 respectively, P < 0.01). The number of unhealed sites inthe aspirin group was significantly greater than in thecontrol or acid inhibition groups; however, TGF-levels were not different from the surrounding mucosa. TGF- increased in the controls afterbiopsy; the increase was significant in the body at week2 only. Aspirin significantly increased TGF-levels in the gastric body and duodenum after one week. The rise in antral TGF- appeared delayedand blunted by the aspirin treatment compared tocontrol. There was no relationship between the number ofvisible biopsy sites, degree of aspirin-induced injury, and the TGF- level. Acid suppression wasassociated with a significant increase in TGF- inthe gastric body and antrum at one week. Immunochemicalstaining did not demonstrate differences inproliferation in any treatment group compared to controls.TGF- levels vary by location in the proximalgastrointestinal tract, with significantly greaterlevels in the antrum. After biopsy, TGF- levelsincrease; short-term aspirin and acid inhibitors modulatethis effect. Aspirin significantly impaired the healingof endoscopic biopsies in the antrum; however, this wasnot associated with changes in TGF- levels. TGF- levels did not change in responseto acid secretory state. Further studies of mucosallevels of TGF- in response to aspirin-inducedinjury in humans appear warranted.     

Streptozotocin-induced diabetes in the Chinese hamster

Summary Streptozotocin treatment (125 mg/kg) in the Chinese hamster induced hyperglycaemia, hypoinsulinaemia, hyperglucagonaemia and changes in body, liver, pancreas, stomach, kidney and adipose tissue weights. The pancreatic reserves of insulin and glucagon in the diabetic animals were low, but stomach glucagon high. These animals showed high levels of phosphoenolpyruvate carboxykinase and low levels of glucokinase, hexokinase, isocitrate dehydrogenase and malic enzyme, but normal levels of pyruvate kinase in the liver. Increases in lactate dehydrogenase subunit B and isozymes 2, 3 and 4 were also observed in the liver, but not in the epididymal fat pad, of the diabetic animals. N-Acetyl--D-glucosaminidase was elevated in plasma, liver and heart, but not in the kidney of the treated animals. Renal -galactosidase and – glucosidase were depressed, whereas -galactosidase and -glucosidase remained essentially normal. These features indicated that there were considerable differences between the biochemical disorders associated with streptozotocin-diabetes in the Chinese hamster and the published observations in the rat.