Circulating microparticles in patients with coronary heart disease and its correlation with interleukin-6 and C-reactive protein

Microparticles (MPs) are vesicles released from activated or apoptotic cells. MP derive from various cells, most notably platelets, but also leucocytes, lymphocytes, erythrocytes, and endothelial cells. The aim of this study was to investigate endothelial MP (EMP), platelet MP (PMP), lymphocyte MP and monocyte MP and TF-positive MPs (TF⁺ MPs) in patients with coronary heart disease (CHD), and to evaluate the correlation of these MPs with Interleukin-6 (IL-6) and C-reactive protein (CRP). Different cell-derived MPs and TF⁺ MPs were analyzed by flow cytometry in 40 patients with myocardial infarction (MI), 30 unstable angina (UA), 20 stable angina (SA) and 20 healthy individuals, and IL-6 and CRP were determined by ELISA and special protein analyzer, respectively. Compared with SA and control, EMP and PMP was significantly elevated in MI and UA (P < 0.001), and TF⁺ MPs was significantly elevated in MI and UA (P < 0.001). EMP and PMP correlated with IL-6 (r = 0.822, P < 0.001 and r = 0.567, P < 0.001; respectively) or CRP level (r = 0.597, P < 0.001 and r = 0.66, P < 0.001; respectively). Different cell-derived MPs in CHD may indicate the different pathophysiological changes in vessels, and MPs may both participate in the development of thrombosis and enhance the vascular inflammation.     

Changes in cardiac Na<Superscript>+</Superscript>/K<Superscript>+</Superscript>-ATPase expression and activity in female rats fed a high-fat diet

The aim of this study was to investigate whether the presence of endogenous estradiol alters the effects of a high-fat (HF) diet on activity/expression of the cardiac Na⁺/K⁺-ATPase, via PI3K/IRS and RhoA/ROCK signalling cascades in female rats. For this study, female Wistar rats (8 weeks old, 150–200 g) were fed a standard diet or a HF diet (balanced diet for laboratory rats enriched with 42% fat) for 10 weeks. The results show that rats fed a HF diet exhibited a decrease in phosphorylation of the α₁ subunit of Na⁺/K⁺-ATPase by 30% (p < 0.05), expression of total α₁ subunit of Na⁺/K⁺-ATPase by 31% (p < 0.05), and association of IRS1 with p85 subunit of PI3K by 42% (p < 0.05), while the levels of cardiac RhoA and ROCK2 were significantly increased by 84% (p < 0.01) and 62% (p < 0.05), respectively. Our results suggest that a HF diet alters cardiac Na⁺/K⁺-ATPase expression via molecular mechanisms involving RhoA/ROCK and IRS-1/PI3K signalling in female rats.     

Myocardial Na+/H+ exchanger-1 (NHE1) content is decreased by exercise training

The effect of exercise training on myocardial Na⁺/H⁺ exchanger-1 (NHE1) protein expression was examined. Adult female Sprague–Dawley rats were randomly divided into sedentary (S; n?=?8) and exercised (E; n?=?9) groups. Twenty-four hours after the last exercise bout, hearts were weighed and connected to an isolated perfused working heart apparatus for evaluation of cardiac functional performance. Heart weight and heart weight/body weight from E rats was significantly increased by 7.1 and 7.2 % (P?<?0.05), respectively, compared with S hearts. The E hearts displayed 15 % greater cardiac output and 35 % external cardiac work compared with the S group at both low and high workloads (P?<?0.05 for both parameters). Left ventricular tissue from the same hearts was homogenized and NHE1 and Na⁺/Ca²⁺ exchanger (NCX) content determined by Western blotting. E hearts had a 38 % (P?<?0.001) reduction in NHE1 content related to S hearts, and there was no difference in NCX content between groups. Cytochrome c oxidase activity in plantaris increased by 100 % (P?<?0.05) and was assessed as a marker of mitochondria content and to verify training status. Our data indicate that exercise training at an intensity that results in cardiac hypertrophy and improved performance is accompanied by decreased NHE1 content in heart.     

The expression of gastric H+-K+-ATPase mRNA and protein in developing rat fundic gland

The proton pump H⁺-K⁺-ATPase is the final common pathway mediating the production and secretion of hydrochloric acid by gastric parietal cells. The present studies were undertaken to examine whether the expression of gastric H⁺-K⁺-ATPase mRNA and protein changes are associated with the development of H⁺-K⁺-ATPase activity in the rat fundic gland. H⁺-K⁺-ATPase activity was examined in rat fundic gland at different stages from gestational day 18.5 to postnatal 8 weeks. The expression of H⁺-K⁺-ATPase mRNA was detected by in situ hybridization using a digoxigenin-labelled RNA probe with a tyramide signal amplification system. The expression of H⁺-K⁺-ATPase protein was evaluated by immunoblotting and immunohistochemistry using antibodies against H⁺-K⁺-ATPase - and -subunits. We found that H⁺-K⁺-ATPase enzyme activity was detectable from the onset of gland formation (day 19.5 of gestation) and increased with age in the developing rat fundic gland. Expression of mRNA and protein was also discernible at the same time, and a progressive increase in expressions was observed as rats developed. Our results suggested that in developing rat fundic gland, the expression of both mRNA and protein of H⁺-K⁺-ATPase increased with age in a manner that parallels the development of H⁺-K⁺-ATPase enzymebreak activity.     

KCNQ1 loss-of-function mutation impairs gastric acid secretion in mice

The KCNQ1 channel is abundantly expressed in the gastric parietal cells. Although the functional coupling of KCNQ1 with the H⁺/K⁺-ATPase has already been confirmed on the basis of pharmacological kinetics, the effect of a KCNQ1 loss-of-function mutation on gastric acidification remains unclear. In this study, parietal cells and gastric glands from both C57BL/6 J mice (normal control) and J343 mice (mice with a KCNQ1 loss-of-function mutation) were isolated to study the effects of KCNQ1 on gastric acidification. We found that the mutation limited intracellular acidification of parietal cells and H⁺ secretion of the stomach in response to histamine. Thus, a KCNQ1 loss-of-function mutation may impair gastric acid secretion.     

Blood Flow of the Acral Finger Arterioles in Patients With Type 2 Diabetes by Quality Doppler Profiles

Patients with diabetes mellitus exhibit peripheral arterioles lesions that is associated with reduced blood flow. Here, we intended to assess the acral arterioles lesion in patients with type 2 diabetes based on the rate of blood flow by multigate spectral Doppler ultrasonography. Fifty-two patients with type 2 DM were divided into two groups. Group 1 included 13 men and 12 women with an average age of 60.60 ± 14.03 years and a duration of type 2 diabetes for 2.44 ± 1.50 years. Group 2 included 17 men and 11 women with an average age of 64.25 ± 10.84 years and type 2 diabetes for 12.57 ± 6.26 years. Age-matched control subjects (n = 52) were recruited (30 men and 22 woman, mean age of 61.19 ± 10.38 years). A multigate spectral Doppler algorithm was applied to the acral finger of the thumb of the right hand to test the arteriole diameter and hemodynamic parameters, including diameter of the acral finger arterioles (D), area of the blood flow profile of the acral finger arterioles (A _max) and hemodynamic parameters. Patients with diabetes exhibited a significant reduction in the arteriole diameter (1.63 ± 0.18 and 1.57 ± 0.22 mm, respectively, P < 0.001 for both) compared to control subjects (2.09 ± 0.17 mm). A _max were significantly reduced in patients with diabetes (61.35 ± 10.66 mm²/s for group 1 and 46.50 ± 6.59 mm²/s for group 2, P < 0.001 for both) compared to that in control subjects (77.93 ± 12.37 mm²/s). Furthermore, a significant difference in Amax was found between group 1 and group 2 (P < 0.001). The vascular resistance index (RI) was significantly higher in both patient groups 0.58 ± 0.06 for group 1 (P < 0.001) and 0.64 ± 0.07 for group 2 (P < 0.001) than that in control subjects (0.48 ± 0.04). The RI value of the acral finger arterioles differed significantly between group 1 and group 2 (P < 0.01). Diabetic patients exhibited a weak blood flow in the acral finger arterioles. The multigate spectral Doppler technology can be used to test blood flow in the acral finger arterioles and provide hemodynamic data for systematic analyses of the peripheral arteriole lesions in diabetes.     

The Central Analgesic Mechanism of YM-58483 in Attenuating Neuropathic Pain in Rats

Calcium channel antagonists are commonly used to treat neuropathic pain. Their analgesic effects rely on inhibiting long-term potentiation, and neurotransmitters release in the spinal cord. Store-operated Ca²⁺channels (SOCCs) are highly Ca²⁺-selective cation channels broadly expressed in non-excitable cells and some excitable cells. Recent studies have shown that the potent inhibitor of SOCCs, YM-58483, has analgesic effects on neuropathic pain, but its mechanism is unclear. This experiment performed on spinal nerve ligation (SNL)-induced neuropathic pain model in rats tries to explore the mechanism, whereby YM-58483 attenuates neuropathic pain. The left L5 was ligated to produce the SNL neuropathic pain model in male Sprague–Dawley rats. The withdrawal threshold of rats was measured by the up–down method and Hargreaves’ method before and after intrathecal administration of YM-58483 and vehicle. The SOCCs in the spinal dorsal horn were located by immunofluorescence. The expression of phosphorylated ERK and phosphorylated CREB, CD11b, and GFAP proteins in spinal level was tested by Western blot, while the release of proinflammatory cytokines (IL-1β, TNF-α, PGE2) was measured by enzyme-linked immunosorbent assay (ELISA). Intrathecal YM-58483 at the concentration of 300 μM (1.5 nmol) and 1000 μM (10 nmol) produced a significant central analgesic effect on the SNL rats, compared with control + vehicle (n = 7, P < 0.001). However, both could not prevent the development of neuropathic pain, compared with normal + saline (P < 0.001). Immunofluorescent staining revealed that Orai1 and STIM1 (the two key components of SOCCs) were located in the spinal dorsal horn neurons. Western blot showed that YM-58483 could decrease the levels of P-ERK and P-CREB (n = 10, #P < 0.05), without affecting the expression of CD11b and GFAP (n = 10, #P > 0.05). YM-58483 also inhibited the release of spinal cord IL-1β, TNF-α, and PGE2, compared with control + vehicle (n = 5, #P < 0.001). The analgesic mechanism of YM-58483 may be via inhibiting central ERK/CREB signaling in the neurons and decreasing central IL-1β, TNF-α, and PGE2 release to reduce neuronal excitability in the spinal dorsal horn of the SNL rats.     

Effects of long-term ouabain treatment on blood pressure, sodium excretion, and renal dopamine D1 receptor levels in rats

To examine the effects of chronic ouabain treatment on blood pressure (BP), sodium excretion, and renal dopamine D₁ receptor level, male Sprague-Dawley (SD) rats were treated with ouabain (27.8 μg kg⁻¹ d⁻¹) intraperitoneally for 5 weeks, and systolic blood pressure (SBP) were recorded weekly. After 5 weeks, sodium excretion and dopamine D₁ receptor agonist fenoldopam-mediated natriuresis were measured, and the expression and phosphorylation levels of the renal cortical dopamine D₁ receptor were confirmed by Western blot analysis. The effects of ouabain on fenoldopam-mediated inhibition of Na⁺-K⁺-ATPase activity were determined by colorimetric assays in human proximal tubular epithelial cells (HK-2 cells). After 5 weeks, the SBP in ouabain group was significantly higher than that in the control group (P < 0.01), but the sodium excretion and renal cortical D₁ receptor expression levels were reduced, and D₁ receptor phosphorylation levels were increased after ouabain treatment. Intravenous administration of fenoldopam caused an increased sodium excretion in control rats, but failed to induce natriuresis in ouabain-treated rats. In addition, fenoldopam induced a dose–respone (10⁻⁹ to 10⁻⁶ M) inhibition of Na⁺-K⁺-ATPase activity in HK-2 cells,but these effects were significantly diminished in HK-2 cells pretreated with nanomolar concentration of ouabain for 5 days (P < 0.01). We propose that the ouabain-induced reduction of the renal dopamine D₁ receptor function serves as a mechanism responsible for sodium retention, and this contributes to the hypertension induced by chronic ouabain treatment.     

Mechanisms associated to impaired activity of cardiac P-type ATPases in endothelial nitric oxide synthase knockout mice

The effect of long-lasting in vivo restriction of nitric oxide (NO) bioavailability on cardiac and renal P-type ATPases critical for intracellular ion homeostasis is controversial. Previous work has shown in eNOS knockout (eNOS^?/?) mice hearts that Na⁺/K⁺- and Ca²⁺-ATPase activities were depressed but the underlying mechanisms are still unclear. The goal of this study was to characterize potential alterations responsible for impaired enzyme activity in eNOS^?/? mice. Na⁺/K⁺-ATPase activity from crude preparations of adult male eNOS^?/? mice hearts and kidneys was reduced compared with wild-type animals (32 %, p?<?0.05 and 16 %, p?<?0.0001, respectively). Immunoblot analysis showed that although the expression of the predominant (or exclusive, for the kidney) Na⁺/K⁺-ATPase α1 isoform was not significantly changed, there was an important downregulation of the less abundant α2 isoform in the heart (57 %, p?<?0.0001). In addition, although cardiac Ca²⁺-ATPase activity was unaltered, the expression of sarco/endoplasmic reticulum Ca²⁺-ATPase 2 protein in eNOS^?/? mice was very high (290 % compared with wild-type animals, p?<?0.0001) without any significant change in phospholamban expression. Consistent with these findings, the content of cardiac and renal free sulfhydryl groups, essential for the catalytic function of such ATPases, was decreased (23 %, p?<?0.01 and 35 %, p?<?0.05, respectively). Altogether, the present results suggest that the absence of eNOS promotes a compartmentalized altered redox balance that affects the activity and expression of ion transport ATPases.     

A role for membrane transport in modulation of intramuscular free glutamine turnover in streptozotocin diabetic rats

We wished to examine the effects of diabetes on muscle glutamine kinetics. Accordingly, female Wistar rats (200 g) were made diabetic by a single injection of streptozotocin (85 mg/kg) and studied 4 days later; control rats received saline. In diabetic rats, glutamine concentration of gastrocnemius muscle was 33% less than in control rats: 2.60 ± 0.06 μmol/g vs. 3.84 ± 0.13 μmol/g (P < 0.001). In gastrocnemius muscle, glutamine synthetase activity (V_max) was unaltered by diabetes (approx. 235 nmol/min per g) but glutaminase V_max increased from 146 ± 29 to 401 ± 94 nmol/min per g; substrate K_m values of neither enzyme were affected by diabetes. Net glutamine efflux (AZ concentration difference × blood flow) from hindlimbs of diabetic rats in vivo was greater than control values (?30.0 ± 3.2 vs. ?1.9 ± 2.6 nmol/min per g (P < 0.001) and hindlimb NH₃ uptake was concomitantly greater (about 27 nmol/min per g). The glutamine transport capacity (V_max) of the Na-dependent System N^m in perfused hindlimb muscle was 29% lower in diabetic rats than in controls (820 ± 50 vs. 1160 ± 80 nmol/min per g (P < 0.01)), but transporter K_m was the same in both groups (9.2 ± 0.5 nM). The difference between inward and net glutamine fluxes indicated that glutamine efflux in perfused hindlimbs was stimulated in diabetes at physiological perfusate glutamine (0.5 mM); ammonia (1 mM in perfusate) had little effect on net glutamine flux in control and diabetic muscles. In Intramuscular Na⁺ was 26% greater in diabetic (13.2 μmol/g) than control muscle, but muscle K⁺ (100 μmol/g) was similar. The accelerated rate of glutamine release from skeletal muscle and the lower muscle free glutamine concentration observed in diabetes may result from a combination of; (i), a diminished Na⁺ electrochemical gradient (i.e., the net driving force for glutamine accrual in muscle falls); (ii), a faster turnover of glutamine in muscle and (iii), an increased V_max/K_m for sarcolemmal glutamine efflux.     

Calmodulin blocker inhibits Ca++-ATPase activity in secretory ameloblast of rat incisor

Summary The effects of the calmodulin blocker, trifluoperazine (TEP), on membrane-bound Ca⁺⁺ -ATPase, Na⁺ -K⁺ -ATPase (EC 3.6.1.3.) and the ultrastructure of the enamel organ were investigated in the lower incisors of normal and TFP-injected rats. The rats, of about 100 g body weight, were given either 0.2 ml physiological saline or 100 g TFP dissolved in 0.2 ml physiological saline through a jugular vein and fixed by transcardiac perfusion with a formaldehyde-glutaraldehyde mixture at 1 and 2 h after TFP administration. Non-decalcified sections of the enamel organ less than 50 m in thickness, prepared from dissected lower incisors, were processed for the ultracytochemical demonstration of Ca⁺⁺-ATPase and Na⁺-K⁺ -ATPase by the one-step lead method at alkaline pH. In control saline-injected animals the most intense enzymatic reaction of Ca⁺⁺-ATPase was demonstrated along the plasma membranes of the entire cell surfaces of secretory ameloblasts. Moderate enzymatic reaction was also observed in the plasma membranes of the cells of stratum intermedium and papillary layer. Reaction precipitates of Na⁺-K⁺-ATPase activity were localized clearly along the plasma membranes of only the cells of stratum intermedium and papillary layer. The most drastic effect of TFP was a marked disappearance of enzymatic reaction of Ca⁺⁺-ATPase from the plasma membranes of secretory ameloblasts, except for a weak persistent reaction in the basolateral cell surfaces of the infranuclear region facing the stratum intermedium. The cells of stratum intermedium and papillary layer, however, continued to react for Ca⁺⁺-ATPase even after TFP treatment. Similarly, Na⁺-K⁺-ATPase activity in these cells was not inhibited by TFP administration. Ultrastructural examination of secretory ameloblasts revealed that administration of TFP caused no considerable cytological changes and did not act as a cytotoxic agent. These results suggest that secretory ameloblasts may have an active Ca⁺⁺ transport system, which is modulated by an endogenous calmodulin.     

Trans Fatty Acids Enhanced Beta-Amyloid Induced Oxidative Stress in Nerve Growth Factor Differentiated PC12 Cells

The effects of trans fatty acids, elaidic acid (trans-9, C18:1) and linoelaidic acid (trans-9, trans-12 C18:2), at 20 or 40 μM in nerve growth factor differentiated PC12 cells with or without beta-amyloid peptide (Aβ) were examined. Elaidic acid treatment alone did not affect cell viability and oxidative injury associated markers (P > 0.05). However, co-treatments of elaidic acid and Aβ led to more reduction in mitochondrial membrane potential (MMP) and Na⁺-K⁺-ATPase activity, and more increase in DNA fragmentation and 8-hydroxydeoxyguanosine (8-OHdG) production than Aβ treatment alone (P < 0.05). Linoelaidic acid alone exhibited apoptotic and oxidative effects in cells via decreasing MMP and Na⁺-K⁺-ATPase activity, increasing reactive oxygen species (ROS) level, lowering glutathione content and glutathione peroxidase (GPX) activity (P < 0.05). The co-treatments of linoelaidic acid with Aβ further enhanced oxidative damage via enhancing the generation of ROS, nitrite oxide and 8-OHdG, elevating caspase-3, caspase-8 and nitric oxide synthase activities, as well as declining GPX, catalase and superoxide dismutase activities (P < 0.05). These results suggested that the interaction of linoelaidic acid and Aβ promoted oxidative stress and impaired mitochondrial functions in neuronal cells.     

In vitro binding of inorganic mercury to the plasma membrane of rat platelet affects Na+-K+-ATPase activity and platelet aggregation

Hg²⁺ binding to ouabain-sensitive Na⁺-K⁺-ATPase of rat platelet membrane was specific with a K_a of 1.3×10⁹ moles and B_max of 3.8 nmoles/mg protein. The binding of mercury to Na⁺-K⁺-ATPase also inhibits the enzyme significantly (P<0.001), which is greater than its ouabain sensitivity. Further in the cytosol of washed platelets conjugation of reduced glutathione (GSH) to Hg²⁺ is correlated dose dependently (25, 50 and 100 pmoles) to enhanced GSH-S-transferase (GST) activity. It may be concluded from the present in vitro experiments that mercury binds specifically to thiol groups present in the platelet membrane Na⁺-K⁺-ATPase, inhibits the enzyme and induces changes in platelet function, namely, platelet aggregation by interfering with the sodium pump.     

The neuroprotective role of l-cysteine towards the effects of short-term exposure to lanthanum on the adult rat brain antioxidant status and the activities of acetylcholinesterase, (Na+,K+)- and Mg2+-ATPase

Lanthanum (La) is a rare earth element that is widely used for industrial, medical and agricultural purposes. Its neurotoxic effects are linked to its physical and chemical properties and its interaction with certain trace elements and membrane-bound enzymes. The aim of this study was to investigate the effects of short-term La-administration (as LaCl₃, 53 mg/kg) on the adult rat whole brain total antioxidant status (TAS) and the activities of acetylcholinesterase (AChE), Na⁺,K⁺-ATPase and Mg²⁺-ATPase, as well as the potential effect of the co-administration of the antioxidant l-cysteine (Cys, 7 mg/kg) on the above parameters. Twenty-eight male Wistar rats were divided into four groups: A (saline-treated control), B (La), C (Cys),and D (La and Cys). All rats were treated once daily with intraperitoneal injections of the tested compounds, for 1-week. Rats were sacrificed by decapitation and the above mentioned parameters were measured spectrophotometrically. Rats treated with La exhibited a significant reduction in brain TAS (−36%, P < 0.001, BvsA), that was partially limited by the co-administration of Cys (−13%, P < 0.01, DvsA), while Cys (group C) had no effect on TAS. The rat brain AChE activity was found significantly increased by both La (+23%, P < 0.001, BvsA) and Cys (+59%, P < 0.001, CvsA), while it was adjusted to control levels by the co-administration of La and Cys. The activity of rat brain Na⁺,K⁺-ATPase was significantly decreased by La-administration (−28%, P < 0.001, BvsA), while Cys supplementation could not reverse this decrease. The activity of Mg²⁺-ATPase exhibited a slight but statistically significant reduction due to La (−8%, P < 0.01, BvsA), that was further reduced by Cys co-administration (−25%, P < 0.001, DvsA). The above findings suggest that La short-term in vivo administration causes a statistically significant decrease in the rat brain TAS and an increase in AChE activity. Both effects can be, partially or totally, reversed into control levels by Cys co-administration, which could thus be considered for future applications as a neuroprotective agent against chronic exposure to La. The activities of Na⁺,K⁺- and Mg²⁺-ATPase that were inhibited by La, could not be reversed by Cys co-administration. A role for the already reported concentration-dependent interaction of La with Ca-binding sites (such as Ca²⁺-ATPase) might be considered for certain of the above phenomena.     

Aldose reductase,NADPH and NADP+ in normal,galactose-fed and diabetic rat lens

NADPH and NADP⁺ levels were measured in rat lens from normal controls, from galactose-fed and diabetic rats during the first week of cataract formation.The level of NADPH in normal rat lens was determined to be 12.3 ± 0.4 nmol/g wet weight, and that of NADP⁺ 4.6 ± 0.2 nmol/g wet weight. In early cataract formation NADPH levels decreased rapidly during the first 2 days and then remained stable at 76% of control for galactose-fed and 84% for diabetic rats. NADP⁺ levels increased by 38% of control for galactose-fed and 54% for diabetic rats. Calculated NADPH/NADP⁺ ratios dropped from 3.36 ± 0.21 to 1.86 ± 0.16 in galactose fed rats, and from 2.81 ± 0.15 to 1.61 ± 0.16 in diabetic rats (P < 0.001 for both experimental groups). These data are consistent with rapid NADPH oxidation during onset of lens cataracts. No significant changes in aldose reductase enzymatic activity levels were observed in either the galactosemic or the diabetic rats during the times measured.     

Iron toxicity mediated by oxidative stress enhances tissue damage in an animal model of diabetes

Although iron is a first-line pro-oxidant that modulates clinical manifestations of various systemic diseases, including diabetes, the individual tissue damage generated by active oxidant insults has not been demonstrated in current animal models of diabetes. We tested the hypothesis that oxidative stress is involved in the severity of the tissues injury when iron supplementation is administered in a model of type 1 diabetes. Streptozotocin (Stz)-induced diabetic and non-diabetic Fischer rats were maintained with or without a treatment consisting of iron dextran ip at 0.1 mL day^?1 doses administered for 4 days at intervals of 5 days. After 3 weeks, an extensive increase (p < 0.001) in the production of reactive oxygen species (ROS) in neutrophils of the diabetic animals on iron overload was observed. Histological analysis revealed that this treatment also resulted in higher (p < 0.05) tissue iron deposits, a higher (p < 0.001) number of inflammatory cells in the pancreas, and apparent cardiac fibrosis, as shown by an increase (p < 0.05) in type III collagen levels, which result in dysfunctional myocardial. Carbonyl protein modification, a marker of oxidative stress, was consistently higher (p < 0.01) in the tissues of the iron-treated rats with diabetes. Moreover, a significant positive correlation was found between ROS production and iron pancreas stores (r = 0.42, p < 0.04), iron heart stores (r = 0.54, p < 0.04), and change of the carbonyl protein content in pancreas (r = 0.49, p < 0.009), and heart (r = 0.48, p < 0.02). A negative correlation was still found between ROS production and total glutathione content in pancreas (r = ?0.50, p < 0.03) and heart (r = ?0.45, p < 0.04). In conclusion, our results suggest that amplified toxicity in pancreatic and cardiac tissues in rats with diabetes on iron overload might be attributed to increased oxidative stress.     

Immunocytochemical localization of H+?K+-ATPase in the rat colon

Summary The presence and distribution of gastric-type H⁺−K⁺-ATPase were investigated in the rat colon using a monoclonal antibody raised against hog gastric H⁺−K⁺-ATPase. Rat stomach was used as positive control. Rat kidney and ileum, in both of which H⁺−K⁺-ATPase has been reported in the past, were also studied. In stomach, very strong staining was found confined to the parietal cells, and a strong band atM _r∼94 kDa on the immunoblots. In colon a moderate staining was found in the supranuclear region of the epithelial cells, with similar intensity and distribution of staining of the surface and deep mucosa of the crypts, throughout the length of the colon. Another monoclonal antibody, specific to the 31 kDa subunit of H⁺-ATPase, used as a negative control, or omission of the primary antibody, resulted in lack of any staining in either colon or stomach. On immunoblots of homogenates of colonic mucosa, no specific band could be identified, either due to very low expression of the H⁺−K⁺-ATPase or loss of antigenicity of the epitope during the processing steps. No positive staining was observed in rat kidney and ileum, suggesting that they contain isoforms that are structurally different.     

Two novel SNPs in the coding region of the bovine PRDM16 gene and its associations with growth traits

As a zinc-finger protein, PR domain containing 16 (PRDM16) controls brown fat determination by stimulating brown fat-selective genes expression while suppressing the expression of genes selective for white fat cells, whose mutations were associated with myelodysplastic syndrome (MDS) and leukemogenesis in human and murine model of leukemia. To date, no polymorphisms of PRDM16 gene in bovine had been reported. Herein, PCR-SSCP and DNA sequencing methods were employed to screen the genetic variation within PRDM16 gene in 1031 Chinese indigenous bovine. The results revealed two novel silent mutations: XM_001788152: m.1641T>C (547aa), 1881G>A (627aa). Hence, we described the PvuII and HaeIII forced PCR–RFLP methods for detecting these mutations, respectively. In the forced PCR–RFLP analysis with PvuII, the frequencies of bovine PRDM16-C allele varied from 0.044 to 0.506 in four Chinese native breeds. In the forced PCR–RFLP analysis with HaeIII, the frequencies of bovine PRDM16-G allele were 0.474, 0.494, 0.576 and 0.906 for Jiaxian (JX), Nanyang (NY), Qinchuan (QC) and Chinese Holstein (CH) population. Significant statistical differences between genotypic frequencies implied that both of the polymorphic loci were significantly associated with cattle breeds by the chi square test (χ² = 190.058, P < 0.001 and χ² = 118.239, P < 0.001 for PvuII; χ² = 209.842, P < 0.001 and χ² = 108.711, P < 0.001 for HaeIII). The associations of the PvuII and HaeIII forced PCR–RFLPs of bovine PRDM16 loci with growth traits were analyzed in Nanyang breed. The two SNPs were associated with body weight and average daily gain in Nanyang aged 12 months, individuals with genotype TT and AA showed significantly better body weight (P < 0.05) and average daily gain (P < 0.01) at 12 months, respectively.     

Studies on (Na+-K+)-activated ATPase XXXIV. Phosphatidylserine not essential for (Na+-K+)-ATPase activity

An (Na⁺-K⁺)-ATPase preparation, consisting of NaI-treated microsomes from cattle brain, was incubated with a phosphatidylserine decarboxylase preparation from Escherichia coli. This led to a reduction in the phosphatidylserine content from 10.1 % to less than 0.1%, accompanied by an equimolar formation of phosphatidylethanolamine. Since the (Na⁺-K⁺)-ATPase activity was not reduced, it can be concluded that phosphatidylserine is not essential for the Na⁺-K⁺)-ATPase activity.     

Neuroprotective Effect of Atorvastatin Involves Suppression of TNF-α and Upregulation of IL-10 in a Rat Model of Intracerebral Hemorrhage

We evaluated the neuroprotective effects of atorvastatin (2, 5, and 10 mg/kg) on experimentally induced intracerebral hemorrhage (ICH) in adult rats; controls were administered PBS. Plasma TNF-α and IL-10 levels before and after ICH were analyzed at various time points by enzyme-linked immunosorbent assay (ELISA) and neurological behavior of rats was assessed by climbing scores. At 3-days postoperatively, brain water contents and TNF-α/IL-10 expression in brain tissue were determined. Histopathological changes and microglial cells in the brain tissue were evaluated by light-microscopy. Post-ICH neurological deficits differed significantly between sham-operated group A and experimental-ICH group B (P < 0.05). Brain water contents were significantly less in group A than in group B (P < 0.05). Significant differences (P < 0.05) between two groups were observed regarding activated microglia, TNF-α and IL-10 levels. Compared with group B, neurological deficits, brain water contents, pathological changes, and activated microglia were reduced (P < 0.05) in groups C (Experimental-ICH + atorvastatin 2 mg/kg), D (Experimental-ICH + atorvastatin 5 mg/kg) and E (Experimental-ICH + atorvastatin 10 mg/kg). Atorvastatin-induced a dose-dependent reduction of TNF-α and increase of IL-10 levels (P < 0.05). Therefore, it was concluded that atorvastatin improved neurofunctional rehabilitation in rats through the suppression of cytokines-mediated inflammatory response and attenuation of brain damage following intracerebral hemorrhage.