AIMTo observe the effect of nonselective nitro oxide synthase inhibitor N(G)-nitro-L-arginine(L-NA) on mitochondria injury in focal cerebral ischemia rats.

METHODSThe rats were randomly divided into sham, ischemia and L-NA treatment group. The model of focal cerebral ischemia was prepared with thread embolism in rats. L-NA was administrated respectively at 2 h, 6 h, 12 h after middle cerebral artery occlusion (MCAO). Rats were killed and the mitochondria of cerebral tissue were isolated by differential centrifugation after L-NA treatment for 3 days. The swelling and the activity of mitochondria, and the activities of ATPase, SOD, GSH-Px in mitochondria and the contents of NO, MDA in mitochondria were measured. Ultrastructure changes of neuronal mitochondria were examined by electronic microscope in ischemia and L-NA treatment group.

RESULTSThe swelling of mitochondria was markedly increased and the activity of mitochondria was decreased, and the contents of mitochondria NO and MDA were markedly increased, the activity of ATPase, SOD and GSH-Px in mitochondria were decreased significantly after MCAO. Compared with ischemia group, the contents of NO were decreased after ischemia 2h, 6h, 12h administered by L-NA, and the swelling of mitochondria was decreased and the activity of mitochondria was increased, and the activities of ATPase, SOD, GSH-Px in mitochondria were enhanced and the contents of MDA in mitochondria were decreased after ischemia 12 h administered by L-NA. The neuronal cytoplasm and the mitochondria swelled, the cristae were disrupted, dissolved or disappeared in MCAO rats. Administration of L-NA could reduce these changes induced by cerebral ischemia in rats.

CONCLUSIONIt could be concluded that L-NA could beneficially inhibit NO production. But it could't protect brain against damage in ischemia acute stage. It could improve mitochondria energy pump, ameliorate oxidative injury and increase the activities of mitochondria during postischemia, and then could effectively protect brain against damage induced by focal cerebral ischemia.

Animals ; Arginine ; pharmacology ; Brain ; metabolism ; Brain Ischemia ; metabolism ; pathology ; Male ; Mitochondria ; metabolism ; pathology ; Rats ; Rats, Wistar

OBJECTIVETo study the effect of vasopressin on aquaporin 7 (AQP7) expression in rat inner ear and reveal the possible role of aquaporins in the formation of endolymphatic hydrops induced by vasopressin.

METHODSWistar rats were intraperitoneally injected with 50 microg/kg arginine vasopressin once a day for one week. Differentially expressed genes of aquaporins induced by vasopressin injection in rat inner ear were filtered by cDNA microarray. The changes of mRNA expression level of AQP7 in inner ear of rats treated with vasopressin injection were measured by RT-PCR.

RESULTSDifferentially expressed gene AQP7 of aquaporins induced by vasopressin injection was screened out in rat inner ear. The expression level of AQP7 mRNA in inner ear of rats treated with vasopressin injection was significantly lower.

CONCLUSIONVasopressin may down-regulate the expression of AQP7 mRNA in the endolymphatic sac and induce a decreased absorption of endolymph, which decreases the water permeability in the potassium ions recycle pathway in the organ of Corti and disturbs the circulation of endolymph, resulting in endolymphatic hydrops.

Animals ; Aquaporins ; genetics ; metabolism ; Arginine Vasopressin ; metabolism ; Ear, Inner ; metabolism ; Endolymphatic Hydrops ; genetics ; metabolism ; Gene Expression ; Rats ; Rats, Wistar

OBJECTIVECorynebacterium crenatum MT, a mutant from C. crenatum AS 1.542 with a lethal argR gene, exhibits high arginine production. To confirm the effect of ArgR on arginine biosynthesis in C. crenatum, an intact argR gene from wild-type AS 1.542 was introduced into C. crenatum MT, resulting in C. crenatum MT. sp, and the changes of transcriptional levels of the arginine biosynthetic genes and arginine production were compared between the mutant strain and the recombinant strain.

METHODSQuantitative real-time polymerase chain reaction was employed to analyze the changes of the related genes at the transcriptional level, electrophoretic mobility shift assays were used to determine ArgR binding with the argCJBDF, argGH, and carAB promoter regions, and arginine production was determined with an automated amino acid analyzer.

RESULTSArginine production assays showed a 69.9% reduction in arginine from 9.01 ± 0.22 mg/mL in C. crenatum MT to 2.71 ± 0.13 mg/mL (P<0.05) in C. crenatum MT. sp. The argC, argB, argD, argF, argJ, argG, and carA genes were down-regulated significantly in C. crenatum MT. sp compared with those in its parental C. crenatum MT strain. The electrophoretic mobility shift assays showed that the promoter regions were directly bound to the ArgR protein.

CONCLUSIONThe arginine biosynthetic genes in C. crenatum are clearly controlled by the negative regulator ArgR, and intact ArgR in C. crenatum MT results in a significant descrease in arginine production.

Arginine ; biosynthesis ; Bacterial Proteins ; chemistry ; genetics ; metabolism ; Corynebacterium ; genetics ; metabolism ; Gene Expression Regulation, Bacterial ; Repressor Proteins ; chemistry ; genetics ; metabolism

AIMTo investigate the influence of hypoxia on postnatal developing pattern of hypothalamic corticotropin releasing factor(CRF) and arginine vasopressin (AVP) in male and female neonatal rats.

METHODSThe hypoxia was simulated in hypobaric cabin. The content of AVP and CRF was assayed by RIA method.

RESULTSIt was showed the female rats had the similar developing process with male rats, either at 2300 m or at 5000 m altitude. When they developed at simulated 5000 m altitude, the content of their hypothalamic CRF was lower than that of control rats on postnatal day 21, while the content of AVP was higher than control on day 21 and 28.

CONCLUSIONMaybe the difference of the function between hypothalamic CRF and AVP or/and the incoherence of their developing stage contribute to their particular developing pattern at 5000 m altitude.

Altitude ; Animals ; Animals, Newborn ; Arginine Vasopressin ; metabolism ; Corticotropin-Releasing Hormone ; metabolism ; Female ; Hypothalamus ; metabolism ; Hypoxia ; Male ; Rats ; Rats, Wistar

Recently it is known that nitric oxide(NO) generated by an activatedmacrophage plays an important role in tumoricidal or bactericidal activity. Thisstudy was done to know the effects of NO produced by the activated macrophages onthe growth of the murine bladder tumor cell line (MBT-2). For the activation ofmacrophages, RAW 264.7 cell line ( macrophage-derived cell line) and peritonealmacrophages from Balb/c mouse were treated with interferon-r (INF-r),lipopolysaccharide ( LPS) or INF-r plus LPS and for the evaluation of growthinhibition of MBT -2 cell line, tritiated thymidine (3[H] -thymidine)incorporation was measured after coculturing of MBT-2 cell line with macrophageswhich had been activated to produce NO. The results are as follows : l.Peritoneal macrophages from Balb/c mouse could be activated to produce NO onlywhen they are stimulated by the combination of INF-r and LPS (35+/-1.0uM/L). Theycould produce a slight increase amount of NO when they had been stimulated byINF-r (11+/-2.5uM/ L) or LPS (14+/-3.5uM/L) compared to control macrophages(8+/-2.5uM/L). The induction of NO production by INF-r plus LPS could be abrogatedby the use of NG-monomethyl-L- arginine (NGMMA), a competitive inhibitor of NOsynthase (5+/-1.5 M/L). 2. RAW 264.7 cell lines could be activated to produce NOby the treatment of INF-r, LPS, and INF-r plus LPS (40+/-2.5uM/L, 37+/-3.0uM/Land 51+/-2.6uM/L respectively). When they are treated with NGMMA, they produced nomore NO even though they had been stimulated with INF-r plus LPS (14+/-4.0uM/L),and they could produce small .amount of NO(19+/-1.0uM/L) in the absence of thestimulation. 3. The incorporation of 3[H] -thymidine of the MBT-2 and peritonealmacrophages was reduced when the cells had been treated with INF-r plus LPScompared to the control (14,519+/-1,087cpm, 20,716+/-1,474cpm respectively).There was no reduction in the incorporation of 3[H] -thymidine when the cellshad been treated with INF-r or LPS alone. The incorporation of 3[H]-thymidineincreased when the cells had been treated with INF-r plus LPS in the presence ofNGMMA(19,622+/-1,341cpm). 4. The incorporation of 3[H] -thymidine of the MBT-2 and RAW 264.7 cell lines were reduced when the cells had been treated with INF-r, LPS and INF-r plus LPS (19.068+/-144cpm, 15,070+/-122cpm and 7,543+/-85cpm respectively) compared to control( 20,708+/-142cpm). When the cells had been pretreated with NGMMA, the incorporation of 3[H]- thymidine recovered to same degree (12,605+/-108cpm) compared to the cells stimulated with INF-r plus LPS. The above correlation of the NO production from macrophages which had been stimulated by INF-r and/or LPS and the inhibition of growth of the tumor cells suggests that NO produced by stimulated macrophages might be the responsible molecule in the defense system of the body against tumors.
Animals ; Arginine ; Cell Line* ; Macrophages* ; Macrophages, Peritoneal ; Metabolism* ; Mice ; Nitric Oxide ; Nitrogen* ; Thymidine ; Urinary Bladder Neoplasms

The effects of the feed attractants on Whitmania pigra were studied. The average weight of Wh. pigra were 5.0 g. Arginine was selected as feed attractants, xanthan gum was selected as feed substrate. The times of Wh. pigra going into the inducing room were recorded. The water temperature was 22-25 degrees C during the whole experiment. Arginine that had better inducing effect was chosen to carry on in the gradient experiment. The results showed that the best inducing effect was found when the added amount of arginine was 0.3%, which was close to the arginine content of the natural body fluid of Wh. Pigra and Bellamya purificata, 2.97 mg x g(-1).
Animal Feed ; analysis ; Animals ; Arginine ; analysis ; metabolism ; Body Weight ; Feeding Behavior ; Leeches ; growth & development ; physiology

Objective: To verify whether the enzymatic activity of kynureninase (KYNU) could be changed by the Arg188Gln (G/A) mutation. Methods: The total RNA of human hepatic tissue was extracted and the KYNU gene cDNA was amplified by RT-PCR. Primers were designed according to the sequences around the site Arg188Gln of KYNU gene and the Arg188Gln (G/A) mutant KYNU cDNA was generated by site-directed mutagenesis. Both the wild-type and mutant-type KYNU genes were subcloned into pcDNA vectors and the recombinant plasmids were constructed. After being transfected into human embryonic kidney 293 (HEK293) cells, the expression of KYNU recombinant plasmids were assessed by Western blot. The enzymatic activities of KYNU were detected by high performance liquid chromatography (HPLC). Results: The KYNU enzyme activities were expressed in both wild and mutant HEK293 cells. Michaelis constants (Km) of the wild and mutant KYNU were (9.833±0.513) μmol/L and (29.900±0.265) μmol/L, respectively (P<0.05). The maximum velocities (Vmax) of the wild and mutant KYNU were (0.700±0.096) nmol·mg^-1·min^-1 and (0.084±0.003) nmol·mg^-1·min^-1, respectively (P<0.05). Conclusion: Arg188Gln (G/A) mutation can decrease the enzymatic activity of KYNU.
Arginine ; genetics ; Enzyme Activation ; genetics ; HEK293 Cells ; Humans ; Hydrolases ; genetics ; metabolism ; Mutation ; Plasmids

The present study investigated the effect of emodin on the serum metabolite profiles in the chronic constriction injury(CCI) model by non-target metabolomics and explored its analgesic mechanism. Twenty-four Sprague Dawley(SD) rats were randomly divided into a sham group(S), a CCI group(C), and an emodin group(E). The rats in the emodin group were taken emodin via gavage once a day for fifteen days(50 mg·kg~(-1)) on the first day after the CCI surgery. Mechanical withdrawal threshold(MWT) and thermal withdrawal threshold(TWL) in each group were performed before the CCI surgery and 3,7, 11, and 15 days after surgery. After 15 days, blood samples were collected from the abdominal aorta. The differential metabolites were screened out by non-target metabolomics and analyzed with Kyoto Encyclopedia of Genes and Genomes(KEGG) and ingenuity pathway analysis(IPA). From the third day after CCI surgery, the MWT and TWL values were reduced significantly in both CCI group and emodin group, compared with the sham group(P<0.01). At 15 days post-surgery, the MWT and TWL values in emodin group increased significantly compared with the CCI group(P<0.05). As revealed by non-target metabolomics, 72 differential serum metabolites were screened out from the C-S comparison, including 41 up-regulated and 31 down-regulated ones, while 26 differential serum metabolites from E-C comparison, including 10 up-regulated and 16 down-regulated ones. KEGG analysis showed that the differential metabolites in E-C comparison were enriched in the signaling pathways, such as sphingolipid metabolism, arginine biosynthesis, glycerophospholipid metabolism, and tryptophan metabolism. IPA showed that the differential metabolites were mainly involved in the lipid metabolism-molecular transport-small molecule biochemistry network. In conclusion, emodin can exert an analgesic role via regulating sphingolipid metabolism and arginine biosynthesis.
Analgesics/pharmacology* ; Animals ; Arginine ; Emodin/pharmacology* ; Neuralgia/metabolism* ; Rats ; Rats, Sprague-Dawley ; Sphingolipids

Microcystin-leucine arginine (MC-LR), a potentially carcinogenic toxin, is produced by Cyanobacteria such as Microcystis and Ananabacteria during water bloom. Increasing evidence demonstrated that MC-LR induces male reproductive toxicity, mainly by inducing germ cell apoptosis, destroying cell cytoskeleton, interfering with DNA damage repair pathway, and damaging blood-testicular barrier (BTB), which eventually lead to male sterility. Testicular Sertoli cells are the somatic cells that directly contact with spermatogenic cells in seminiferous tubules. They not only regulate immune response to maintain testicular immune homeostasis by secreting a variety of cytokines and immunosuppressive factors, but also provide the protective effects of spermatogenic cells by forming BTB. MC-LR induces inflammation and apoptosis of Sertoli cells, and destroys the integrity of the BTB, and then causes spermatogenesis dysfunction.
Male ; Humans ; Sertoli Cells ; Leucine/pharmacology* ; Arginine/pharmacology* ; Microcystins/metabolism* ; Immunity

Glucose homeostasis is tightly controlled by the regulation of glucose production in the liver and glucose uptake into peripheral tissues, such as skeletal muscle and adipose tissue. Under prolonged fasting, hepatic gluconeogenesis is mainly responsible for glucose production in the liver, which is essential for tissues, organs, and cells, such as skeletal muscle, the brain, and red blood cells. Hepatic gluconeogenesis is controlled in part by the concerted actions of transcriptional regulators. Fasting signals are relayed by various intracellular enzymes, such as kinases, phosphatases, acetyltransferases, and deacetylases, which affect the transcriptional activity of transcription factors and transcriptional coactivators for gluconeogenic genes. Protein arginine methyltransferases (PRMTs) were recently added to the list of enzymes that are critical for regulating transcription in hepatic gluconeogenesis. In this review, we briefly discuss general aspects of PRMTs in the control of transcription. More specifically, we summarize the roles of four PRMTs: PRMT1, PRMT 4, PRMT 5, and PRMT 6, in the control of hepatic gluconeogenesis through specific regulation of FoxO1- and CREB-dependent transcriptional events.
Acetyltransferases ; Adipose Tissue ; Arginine* ; Brain ; Erythrocytes ; Fasting ; Gluconeogenesis ; Glucose* ; Homeostasis ; Liver ; Metabolism* ; Methyltransferases* ; Muscle, Skeletal ; Phosphoric Monoester Hydrolases ; Phosphotransferases ; Protein-Arginine N-Methyltransferases ; Transcription Factors