The efficacy and safety of myo-inositol supplementation for the prevention of gestational diabetes mellitus in overweight and obese pregnant women: A systematic review and meta-analysis / Journal of the ASEAN Federation of Endocrine Societies

Background@#Myo-inositol has emerged as one of the preventive therapies for the development of gestational diabetes mellitus in at-risk populations. This systematic review and meta-analysis was conducted to determine the efficacy and safety of myo-inositol in decreasing the incidence of gestational diabetes in overweight and obese pregnant women.@*Methodology@#This meta-analysis was conducted using the standard Cochrane methodology and reported in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) 2020 guidelines. Inclusion criteria were randomized controlled trials (RCTs) that enrolled overweight and obese pregnant women and used myo-inositol supplementation. The primary outcome was the incidence of gestational diabetes mellitus at 24-28 weeks. Secondary outcomes included cesarean section rate, the incidence of pregnancy-induced hypertension, macrosomia and preterm delivery. Risk ratios (RRs) and 95% confidence intervals (CIs) were used for dichotomous data.@*Results@#Six RCTs were included. Compared to standard micronutrient supplementation, standard dose of myo-inositol (4 g) may reduce the incidence of GDM (RR 0.54; CI [0.30, 0.96]; n = 887 women), but the certainty of evidence is low to very low. With low-dose myo-inositol however, evidence is uncertain about its benefit on the incidence of gestational diabetes mellitus in overweight and obese women with RR 0.71; CI [0.14, 3.50]. No adverse effects were noted. For the secondary outcomes, standard dose myo-inositol appears to reduce the incidence of pregnancy-induced hypertension and preterm delivery, but the certainty of evidence is low to very low.@*Conclusion@#Current evidence is uncertain on the potential benefit of myo-inositol supplementation in overweight and obese pregnant women. While studies show that 4 g myo-inositol per day may decrease the incidence of GDM, pregnancy-induced hypertension and pre-term birth with no associated risk of serious adverse events, the certainty of evidence is low to very low. Future high-quality trials may provide more compelling evidence to support practice recommendations.

Effects of Mlx-8, a phospholipase A2 from Brazilian coralsnake Micrurus lemniscatus venom, on muscarinic acetylcholine receptors in rat hippocampus

Here, we described the presence of a neurotoxin with phospholipase A2 activity isolated from Micrurus lemniscatus venom (Mlx-8) with affinity for muscarinic acetylcholine receptors (mAChRs). Methods: The purification, molecular mass determination, partial amino acid sequencing, phospholipase A2 activity determination, inhibition of the binding of the selective muscarinic ligand [3H]QNB and inhibition of the total [3H]inositol phosphate accumulation in rat hippocampus of the Mlx-8 were determined. Results: Thirty-one fractions were collected from HPLC chromatography, and the Mlx-8 toxin was used in this work. The molecular mass of Mlx-8 is 13.628 Da. Edman degradation yielded the following sequence: NLYQFKNMIQCTNTRSWL-DFADYG-CYCGRGGSGT. The Mlx-8 had phospholipase A2 enzymatic activity. The pKi values were determined for Mlx-8 toxin and the M1 selective muscarinic antagonist pirenzepine in hippocampus membranes via [3H]QNB competition binding assays. The pKi values obtained from the analysis of Mlx-8 and pirenzepine displacement curves were 7.32 ± 0.15, n = 4 and 5.84 ± 0.18, n = 4, respectively. These results indicate that Mlx-8 has affinity for mAChRs. There was no effect on the inhibition ability of the [3H]QNB binding in hippocampus membranes when 1 µM Mlx-8 was incubated with 200 µM DEDA, an inhibitor of phospholipase A2. This suggests that the inhibition of the phospholipase A2 activity of the venom did not alter its ability to bind to displace [3H]QNB binding. In addition, the Mlx-8 toxin caused a blockade of 43.31 ± 8.86%, n = 3 and 97.42 ± 2.02%, n = 3 for 0.1 and 1 µM Mlx-8, respectively, on the total [3H]inositol phosphate content induced by 10 µM carbachol. This suggests that Mlx-8 inhibits the intracellular signaling pathway linked to activation of mAChRs in hippocampus. Conclusion: The results of the present work show, for the first time, that muscarinic receptors are also affected by the Mlx-8 toxin, a muscarinic ligand with phospholipase A2 characteristics, obtained from the venom of the Elapidae snake Micrurus lemniscatus, since this toxin was able to compete with muscarinic ligand [3H]QNB in hippocampus of rats. In addition, Mlx-8 also blocked the accumulation of total [3H]inositol phosphate induced by muscarinic agonist carbachol. Thus, Mlx-8 may be a new pharmacological tool for examining muscarinic cholinergic function.(AU)

Antiallodynic effects of vitamin C and vitamin E in chronic post-ischemia pain rat model / 대한마취과학회지

BACKGROUND: Recent research has shown that reactive oxygen species (ROS) play a significant role in the development and persistence of neuropathic pain through central sensitization via N-methyl-D-aspartate (NMDA) receptor activation. In the present study, we examined whether the intraperitoneal administration of vitamins C and E alone or together could alleviate mechanical allodynia in a chronic post-ischemia pain (CPIP) rat model. METHODS: Vitamins C and E were administered intraperitoneally to 48 male Sprague Dawley rats once per day for 3 days before hindpaw ischemia-reperfusion (I/R) injury was induced. On the third day, the CPIP rat model was produced by inducing ischemia in the left hindpaw by applying an O-ring for 3 h, followed by reperfusion. Three days after reperfusion, hindpaw mechanical allodynia was assessed by measuring the withdrawal response to von Frey filament stimulation. The rats were sacrificed immediately after behavioral testing to determine the phosphorylated NMDA receptor subunit 1 (pNR1) and extracellular-signal-regulated kinases (pERK) levels in the spinal cord. RESULTS: When the antioxidant vitamins C and E were administered intraperitoneally to CPIP rats, I/R injury-induced mechanical allodynia was attenuated, and pNR1 and pERK levels were decreased in the rat spinal cord. Additionally, the co-administration of both vitamins had an increased antiallodynic effect. CONCLUSIONS: The reduced phosphorylated NR1 and ERK levels indicate that vitamins C and E inhibit the modulation of spinal cord neuropathic pain processing. Co-administration of vitamins C and E had a greater antiallodynic effect.

Mercury Promotes Catecholamines Which Potentiate Mercurial Autoimmunity and Vasodilation: Implications for Inositol 1,4,5-Triphosphate 3-Kinase C Susceptibility in Kawasaki Syndrome

Previously, we reviewed biological evidence that mercury could induce autoimmunity and coronary arterial wall relaxation as observed in Kawasaki syndrome (KS) through its effects on calcium signaling, and that inositol 1,4,5-triphosphate 3-kinase C (ITPKC) susceptibility in KS would predispose patients to mercury by increasing Ca2+ release. Hg2+ sensitizes inositol 1,4,5-triphosphate (IP3) receptors at low doses, which release Ca2+ from intracellular stores in the sarcoplasmic reticulum, resulting in delayed, repetitive calcium influx. ITPKC prevents IP3 from triggering IP3 receptors to release calcium by converting IP3 to inositol 1,3,4,5-tetrakisphosphate. Defective IP3 phosphorylation resulting from reduced genetic expressions of ITPKC in KS would promote IP3, which increases Ca2+ release. Hg2+ increases catecholamine levels through the inhibition of S-adenosylmethionine and subsequently catechol-O-methyltransferase (COMT), while a single nucleotide polymorphism of the COMT gene (rs769224) was recently found to be significantly associated with the development of coronary artery lesions in KS. Accumulation of norepinephrine or epinephrine would potentiate Hg2+-induced calcium influx by increasing IP3 production and increasing the permeability of cardiac sarcolemma to Ca2+. Norepinephrine and epinephrine also promote the secretion of atrial natriuretic peptide, a potent vasodilator that suppresses the release of vasoconstrictors. Elevated catecholamine levels can induce hypertension and tachycardia, while increased arterial pressure and a rapid heart rate would promote arterial vasodilation and subsequent fatal thromboses, particularly in tandem. Genetic risk factors may explain why only a susceptible subset of children develops KS although mercury exposure from methylmercury in fish or thimerosal in pediatric vaccines is nearly ubiquitous. During the infantile acrodynia epidemic, only 1 in 500 children developed acrodynia whereas mercury exposure was very common due to the use of teething powders. This hypothesis mirrors the leading theory for KS in which a widespread infection only induces KS in susceptible children. Acrodynia can mimic the clinical picture of KS, leading to its inclusion in the differential diagnosis for KS. Catecholamine levels are often elevated in acrodynia and may also play a role in KS. We conclude that KS may be the acute febrile form of acrodynia.

Histamine receptors; responses and modulations towards agonist and antagonist on the rabbit ileum, in vitro study

This research work deals with the mechanism of action involved in determining the therapeutic potential of histamine and its blockers in gastrointestinal motility. Rabbits of equal weights were used in this study. They were brought from the animal house of BMSI, sacrificed in the Pharmacology Research laboratory. lleum strip were isolated and with special recommended methodology, longitudinal and circular muscles were separated. Individual muscle strip were then exposed separately to the desired drugs in the organ bath and reading were recorded on the polygraph machine. Basic Medical Sciences Institute, Jinnah Postgraduate Medical Centre, Karachi. 1996 to 1998. Histamine increases the contractile effects of longitudinal and circular muscle. H[1] and H[2] blockers potentiate its effects on longitudinal muscle while in circular muscle no change was observed with H[1] blocker whereas H[2] blocker antagonized the histaminic effects. However when H[1] blocker applied directly it increases the amplitude of contraction in longitudinal and circular muscle whereas H[2] blocker decreases the height of contractions. Histamine in the presence of H[1] and H[2] blocker augmented their effects in longitudinal muscle and antagonizes in circular layer. Gastrointestinal motility can be controlled through histamine and its antagonist. New drugs can be formulated on the basis of this study for the regulation of intestinal motility

Superoxide and Nitric Oxide Involvement in Enhancing of N-methyl-D-aspartate Receptor-Mediated Central Sensitization in the Chronic Post-ischemia Pain Model

BACKGROUND: Recent studies indicate that reactive oxygen species (ROS) are involved in persistent pain, including neuropathic and inflammatory pain. Since the data suggest that ROS are involved in central sensitization, the present study examines the levels of activated N-methyl-D-aspartate (NMDA) receptors in the dorsal horn after an exogenous supply of three antioxidants in rats with chronic post-ischemia pain (CPIP). This serves as an animal model of complex regional pain syndrome type-I induced by hindpaw ischemia/reperfusion injury. METHODS: The application of tight-fitting O-rings for a period of three hours produced CPIP in male Sprague-Dawley rats. Allopurinol 4 mg/kg, allopurinol 40 mg/kg, superoxide dismutase (SOD) 4,000 U/kg, N-nitro-L-arginine methyl ester (L-NAME) 10 mg/kg and SOD 4,000 U/kg plus L-NAME 10 mg/kg were administered intraperitoneally just after O-ring application and on the first and second days after reperfusion. Mechanical allodynia was measured, and activation of the NMDA receptor subunit 1 (pNR1) of the lumbar spinal cord (L4-L6) was analyzed by the Western blot three days after reperfusion. RESULTS: Allopurinol reduced mechanical allodynia and attenuated the enhancement of spinal pNR1 expression in CPIP rats. SOD and L-NAME also blocked spinal pNR1 in accordance with the reduced mechanical allodynia in rats with CPIP. CONCLUSION: The present data suggest the contribution of superoxide, produced via xanthine oxidase, and the participation of superoxide and nitric oxide as a precursor of peroxynitrite in NMDA mediated central sensitization. Finally, the findings support a therapeutic potential for the manipulation of superoxide and nitric oxide in ischemia/reperfusion related pain conditions.

Participation of the endoplasmic reticulum protein chaperone thio-oxidoreductase in gonadotropin-releasing hormone receptor expression at the plasma membrane

Chaperone members of the protein disulfide isomerase family can catalyze the thiol-disulfide exchange reaction with pairs of cysteines. There are 14 protein disulfide isomerase family members, but the ability to catalyze a thiol disulfide exchange reaction has not been demonstrated for all of them. Human endoplasmic reticulum protein chaperone thio-oxidoreductase (ERp18) shows partial oxidative activity as a protein disulfide isomerase. The aim of the present study was to evaluate the participation of ERp18 in gonadotropin-releasing hormone receptor (GnRHR) expression at the plasma membrane. Cos-7 cells were cultured, plated, and transfected with 25 ng (unless indicated) wild-type human GnRHR (hGnRHR) or mutant GnRHR (Cys14Ala and Cys200Ala) and pcDNA3.1 without insert (empty vector) or ERp18 cDNA (75 ng/well), pre-loaded for 18 h with 1 µCi myo-[2-3H(N)]-inositol in 0.25 mL DMEM and treated for 2 h with buserelin. We observed a decrease in maximal inositol phosphate (IP) production in response to buserelin in the cells co-transfected with hGnRHR, and a decrease from 20 to 75 ng of ERp18 compared with cells co-transfected with hGnRHR and empty vector. The decrease in maximal IP was proportional to the amount of ERp18 DNA over the range examined. Mutants (Cys14Ala and Cys200Ala) that could not form the Cys14-Cys200 bridge essential for plasma membrane routing of the hGnRHR did not modify maximal IP production when they were co-transfected with ERp18. These results suggest that ERp18 has a reduction role on disulfide bonds in wild-type hGnRHR folding.

Apoptosis of the GABAergic interneuron in the dorsal horn of the chronic post-ischemic pain model / 대한마취과학회지

BACKGROUND: It is well known that the GABAergic inhibitory interneuronal system plays an important role in modulation of the noxious stimulation transmitted from the primary afferent input. Some studies have revealed the role that the GABA inhibitory interneuronal system plays in the modulation of pain transmission and the changes in the GABAergic interneurons that occur during the neuropathic pain. This study was conducted to evaluate the apoptosis of the GABAergic interneuron, which is assumed to contribute to neuropathic pain. METHODS: Male Sprague-Dawley rats weighing 290-310 g were used to create a CPIP (chronic post-ischemic pain) model, which was made by placing a tourniquet on the left hindpaw of the rats. The tourniquet was maintained for 3 hours, after which it was released to allow reperfusion. Thirty minutes prior to reperfusion, N-acetyl-L-cysteine (NAC group) or normal saline (control group) was injected. After reperfusion, mechanical allodynia and cold allodynia were measured. In addition, the release of cytochrome c into the cytosol was evaluated through western blot or immunohistochemistry of the spinal cord. RESULTS: Mechanical and cold allodynia developed and the number of GABA interneurons was reduced in the control group. Additionally, The cytochrome c from the GABA interneuron was released into the cytosol in the control group, but the amount released was reduced in response to treatment with NAC. CONCLUSIONS: The results of this study showed that the GABA interneuron in the Rexed laminae I, II released cytochrome c into the cytosol in CPIP neuropathic pain model, which is known to lead to apoptosis. However, treatment with N-acetyl-L-cysteine prevented this process.

Contralateral allodynia and central change in the chronic post-ischemic pain model rats / 대한마취과학회지

BACKGROUND: Mirror-image allodynia is a mysterious phenomenon that occurs in association with many clinical pain syndromes including complex regional pain syndromes (CRPS). Underlying mechanisms for the development of such pain are still a matter of investigation. Several studies suggest that activation of the N-methyl-D-aspartate (NMDA) receptor is essential for central sensitization as a base for persistent pain. The aim is to assess whether alteration of NMDA receptor expression correlates with the contralateral allodynia in the chronic post-ischemia pain (CPIP) model rats representing CRPS-Type I. METHODS: Application of a tight-fitting tourniquet for a period of 3 hours before reperfusion produced CPIP in male Sprague-Dawley rats. The mechanical paw withdrawal thresholds to von Frey stimuli (using a dynamic plantar aesthesiometer) were measured as pain indicators in ipsilateral and contralateral hindpaws. Phosphorylation of the NMDA receptor 1 subunit (pNR1), assessed with Western blot, was measured in the contralateral L4-6 spinal cord. RESULTS: Ipsilateral and contralateral mechanical allodynia is present at 4 hours after reperfusion, peaked at 3 days, and continued for 7 days after reperfusion. The relative density of pNR1 of CPIP rats significantly decreased in the contralateral L4-6 spinal cord compared to baseline value (P < 0.05). There was significant correlation between paw withdrawal threshold and the relative density of pNR1 (ipsilateral; R2 = 0.75, P < 0.01, contralateral; R2 = 0.60, P < 0.01). CONCLUSIONS: These data suggest that pNR1 is correlated to the contralateral mechanical allodynia in CPIP rats.

Differential Expressions of Apoptosis-related Genes in Lung Cancer Cell Lines Determine the Responsiveness to Ionizing Radiation

Radiotherapy would be the choice of treatment for human cancers, because of high cost-effectiveness. However, a certain population of patients shows a resistance to radiotherapy and recurrence. In an effort to increase the efficacy of radiotherapy, many efforts were driven to find the genes causing the unresponsiveness to ionizing radiation. In this paper, we compared the gene expression profiles of two lung cancer cell lines, H460 and H1299, which showed differential responses to ionizing radiations. Each cell were irradiated at 2 Gy, and harvested after 0, 2, 4, 8, 12 and 24 hours to examine the expressions. Two-way ANOVA analysis on time-series experiments of two cells could select 2863 genes differentially expressed upon ionizing radiation among 32,321 genes in microarray (p<0.05). We classified these genes into 21 clusters by SOM clustering according to the interaction between cell types and time. Two SOM clusters were enriched with apoptosis-related genes in pathway analysis. One cluster contained higher levels of phosphatidyl inositol 3-phosphate kinase (PI3K) subunits in H1299, radio resistant cells than H460, radiosensitive cells. TRAIL receptors were expressed in H460 cells while the decoy receptor for TRAIL was expressed in H1299 cells. From these results, we could characterize the differential responsiveness to ionizing radiation according to their differential expressions of apoptosis-related genes, which might be the candidates to increase the power of radiotherapy.

Differential Expressions of Apoptosis-related Genes in Lung Cancer Cell Lines Determine the Responsiveness to Ionizing Radiation

Radiotherapy would be the choice of treatment for human cancers, because of high cost-effectiveness. However, a certain population of patients shows a resistance to radiotherapy and recurrence. In an effort to increase the efficacy of radiotherapy, many efforts were driven to find the genes causing the unresponsiveness to ionizing radiation. In this paper, we compared the gene expression profiles of two lung cancer cell lines, H460 and H1299, which showed differential responses to ionizing radiations. Each cell were irradiated at 2 Gy, and harvested after 0, 2, 4, 8, 12 and 24 hours to examine the expressions. Two-way ANOVA analysis on time-series experiments of two cells could select 2863 genes differentially expressed upon ionizing radiation among 32,321 genes in microarray (p<0.05). We classified these genes into 21 clusters by SOM clustering according to the interaction between cell types and time. Two SOM clusters were enriched with apoptosis-related genes in pathway analysis. One cluster contained higher levels of phosphatidyl inositol 3-phosphate kinase (PI3K) subunits in H1299, radio resistant cells than H460, radiosensitive cells. TRAIL receptors were expressed in H460 cells while the decoy receptor for TRAIL was expressed in H1299 cells. From these results, we could characterize the differential responsiveness to ionizing radiation according to their differential expressions of apoptosis-related genes, which might be the candidates to increase the power of radiotherapy.

The effects of superoxide dismutase on the expression of c-fos gene in the chronic post-ischemic pain model rats / 대한마취과학회지

BACKGROUND: Chronic post-ischemia pain (CPIP) model is reported to represent the complex regional pain syndrome type I. The administration of non-specific free radical scavengers reduced mechanical allodynia, but it is not evident which type of free radical is responsible for the development of CPIP. This study was investigated to elucidate the role of superoxide on the development of CPIP and the relationship with the expression of c-fos gene. METHODS: Male Sprague-Dawley rats weighing 290-310 g were housed in one cage with food and water ad libitum. CPIP model was made by placing a tourniquet on the left hindpaw of rats. The tourniquet maintained for 3 hours, then released to allow reperfusion. Thirty minutes before reperfusion, superoxide dismutase (SOD) or normal saline (control group) was injected. Mechanical allodynia and cold allodynia were measured at 1, 3, 5, 7, 14 and 28 days after reperfusion and compared. Also, spinal cord was harvested and the expression of c-fos gene was measured through the real time reverse transcription polymerase chain reaction. RESULTS: Superoxide dismutase reduced mechanical allodynia (1, 3, 5 and 14 day) and cold allodynia (1, 3 and 7 day) compared with control rats in left hindpaw. Expression of c-fos was significantly reduced in the SOD rats at the day 14 and 28 compare to the control rats. CONCLUSIONS: The administration of superoxide dismutase suppressed the allodynia and c-fos gene expression of CPIP model rats and it may be suggested that the superoxide has an important role in the development of CPIP.

Study of mutation and single nucleotide polymorphism of PDGFRbeta and SHIP gene in acute myeloid leukemia / 中华血液学杂志

<p><b>OBJECTIVE</b>To investigate the significance of mutation and single nucleotide polymorphism (SNP) of class III receptor tyrosine kinases such as PDGFRbeta and SHIP in acute myeloid leukemia (AML) patients.</p><p><b>METHODS</b>Screening of the mutation and SNP of PDGFRbeta and SHIP by genomic PCR, RT-PCR, directly sequencing and Mass-ARRAY system was carried out in 273 AML patients.</p><p><b>RESULTS</b>The mutations of PDGFRbeta R685C and SHIP Q1153L were detected for the first time in AML patients. The positivity ratio was 0.73% and 0.36% respectively.</p><p><b>CONCLUSION</b>The mutations of PDGFRbeta R685C and SHIP Q1153L may contribute to leukemogenesis of AML.</p>

Dietary administration of inositol and/or inositol-6-phosphate prevents chemically-induced rat hepatocarcinogenesis.

Chemoprevention is considered a rational strategy for dietary approaches to prevention of cancer. Multiple lines of evidence suggest that many of our dietary principles are able to intervene in the multistage carcinogenesis process and phytic acid (inositol hexaphosphate, IP6), a phytochemical present in a variety of plant species, has been shown to prevent various cancers, including those of the mammary gland, colon and liver. However, the mechanism of chemoprevention by IP6 has not been fully elucidated. In the present study, we examined the effects of inositol and/or IP6 supplementation on rat hepatocarcinogenesis initiated by diethylnitrosamine (DEN) and promoted by partial hepatectomy (PH). Supplementation with either inositol or IP6, or their combination, starting one week prior to administration of DEN, resulted in a significant decrease in both the area and the number of placental glutathione S-transferase positive (GST-P+) foci, a preneoplastic marker for DEN-initiated hepatocarcinogenesis. The administration of inositol and/or IP6 in drinking water caused marked enhancement in the glutathione S-transferase (GST) activity. In addition, the production of thiobarbituric acid reactive substances and the catalase activity were significantly reduced in rats supplemented with inositol and /or IP6. Based on these findings, it is likely that the chemopreventive effects of inositol and/or IP6 on rat hepatocarcinogenesis initiated by DEN and promoted by PH are associated with induction of GST activity and suppression of lipid peroxidation.

Efffects of Fluoxetine on ATP-induced Calcium Signaling in PC12 Cells

Fluoxetine, a widely used anti-depressant compound, has several additional effects, including blockade of voltage-gated ion channels. We examined whether fluoxetine affects ATP-induced calcium signaling in PC12 cells by using fura-2-based digital calcium imaging and assay for [3H]-inositol phosphates (IPs). Treatment with ATP (100microM) for 2 min induced [Ca2+]i increases. The ATP-induced [Ca2+]i increases were significantly decreased by removal of extracellular Ca2+ and treatment with the inhibitor of endoplasmic reticulum Ca2+ ATPase thapsigargin (1microM). Treatment with fluoxetine for 5 min blocked the ATP-induced [Ca2+]i increase concentration-dependently. Treatment with fluoxetine (30microM) for 5 min blocked the ATP-induced [Ca2+]i increase following removal of extracellular Ca2+ and depletion of intracellular Ca2+ stores. While treatment with the L-type Ca2+ channel antagonist nimodipine for 10 min inhibited the ATP-induced [Ca2+]i increases significantly, treatment with fluoxetine alone blocked the ATP-induced responses. Treatment with fluoxetine also inhibited the 50 mM K+-induced [Ca2+]i increases completely. However, treatment with fluoxetine did not inhibit the ATP-induced [3H]-IPs formation. Collectively, we conclude that fluoxetine inhibits ATP-induced [Ca2+]i increases in PC12 cells by inhibiting both an influx of extracellular Ca2+ and a release of Ca2+ from intracellular stores without affecting IPs formation.

Alimentos funcionais: [revisão] / Functional foods: [review]

Faz-se uma revisão sumária sobre alimentos funcionais com destaque em seus grupos químicos, sua ação fisiológica e suas fontes na dieta.

A brief survey of functional foods is presented with special emphasis on chemical groups, physiological actions, and dietary sources.

Accumulation of cadmium in rats fed diets containing dietary fiber-rich bakery product

Cadmium is a potentially toxic trace element. The use of fertilizers and pesticides has led to an increase of cadmium level in soil. This might increase the intake of cadmium into agricultural crops. On the other hand, wheat bran and carrots are recommended as important sources of dietary fiber. In this study flat bread was prepared by replacing 50% of the flour with wheat bran. Biscuit was also prepared using 15% of the flour as carrot powder. The contents of cadmium were found to be 0.45, 0.57, 0.12 and 0.098 mg/kg in wheat bran, carrot powder, flat bread and biscuit, respectively. Phytic acid, dietary fiber and minerals [zinc, iron, calcium and cupper] contents of bran, carrot powder as well as flat bread and biscuit as bakery products were also determined. The accumulation of cadmium in the liver, kidneys, brain and plasma of rats fed diets containing the previous products for 9 weeks was measured. The results revealed a higher accumulation of cadmium in the case of the animals fed diets containing carrot powder than those fed diets containing wheat bran. The concentrations of inositol phosphate fractions [IP[3], IP[4], IP[5] and IP[6]] were also determined using HPLC method

Purification and characterization of receptors for myoinositol trisphosphate and myoinositol tetrakis phosphate from Entamoeba histolytica.

The microsomal fraction from the log phase of Entamoeba histolytica cells contains Ins(1,4,5)P3 and Ins(1,3,4,5)P4 binding activity. The binding proteins/receptors for both Ins(1,4,5)P3 and Ins(1,3,4,5)P4 were purified and found to be specific for each ligand. The molecular masses for native proteins for InsP3 and InsP4 are 138 kDa and 130 kDa respectively having subunits of 69 kDa and 64 kDa respectively. That these proteins are associated with Ca2+ release was confirmed by including these proteins separately in proteoliposomes and adding InsP3 and InsP4 in both the cases.

Receptores muscarínicos em cêlulas de sertoli de rato / Muscarinic acetylcholine receptors in sertori cells

O objetivo do presente trabalho foi caracterizar os receptores muscarínicos nas células de Sertoli de rato. Cultura primária de células de Sertoli foram obtidas de ratos com 30 dia de idade. O ensaio da transcriptase reversa seguido da reação em cadeia da polimerase (RT-PCR) foi realizado com DNA complementar obtido a partir do RNA mensageiro das células de Sertoii e primers específicos para os cinco subtipos de receptor muscarínico. Foram amplificados a produtos de tamanhos específicos correspondendo aos cinco subtipos: m1 = 641 -, m2 = 552; m3 = 790; m4 = 51O e m5 = 451 pares de bases. Pelo ensaio de proteção à ribonuclease (RPA), utilizando ribosondas produzidas a partir de sequência distinta entre os cinco subtipos de receptores muscarínicos, localizada na terceira alça intracitoplasmática do receptor, foram detectados quatro transcritos para os receptores muscarínicos, correspondentes aos subtipos m1 = 377; m2 = 547; m3 = 687 e m4 = 519 nucleotídeos. Nas condições utilizadas neste último ensaio, o transcrito m5 não foi detectado. Os estudos de saturação foram realizados em células de Sertoli incubadas com o [3H]Quinuclidinyl benzilate ([3H]QNB) (O,1 nM a 4 nM), por 2 horas a 4§ C, na ausência (ligação total) e na presença (ligação inespecífica) de atropina (l nM). A ligação do [3H]QNB às células de Sertoli foi específica, saturável, dependente de tempo e temperatura de incubação. A análise de Scatchard revelou a presença de um único sítio de ligação para o @HIQNB, com uma constante de dissociação (KD = 1,78 ñ O,32 nM) e densidade de receptores (Bmax) = 221,0 ñ 20,0 fmol/mg de proteína. O antagonista muscarínico, atropina (não seletivo), deslocou a ligação específica do [3H]QNB e a melhor curva que se ajustou aos dados foi uma sigmóide complexa, com um coeficiente de Hill de O,47 ñ O,09, sugerindo a presença de mais de um sítio de ligação e/ou estado de afinidade diferente de um mesmo sítio de ligação. Os valores de PKi para a atropina foram 7,9 ñ O,80 e 3,3 ñ O,23. O acúmulo intracelular de AMP cíclico induzido pelo forskolin (lO-5 M) foi determinado na ausência e presença do carbacol (lO-3 M) e diferentes antagonistas muscarínicos. O forskolin, que estimula diretamente a enzima adenililciclase, produziu um aumento, dependente da concentração, no conteúdo intracelular de AMP cíclico. O aumento de AMP cíclico, induzido pelo forskolin (1O-5 M), foi reduzido pelo carbacol 10-5M, 10-4M e 10-3 M de 23 por cento,...(au)

Differential effect of homocysteic acid and cysteic acid on changes of inositol phosphates and (Ca2+)i in rat cerebellar granule cells

The present study was undertaken to characterize homocysteic acid (HCA)-and cysteic acid (CA)mediated formation of inositol phosphates (InsP) in primary culture of rat cerebellar granule cells. HCA and CA stimulated InsP formation in a dose-dependent manner, which was prevented by the N-methyl-D-aspartate (NMDA) receptor antagonist D,L-2-amino-5-phosphopentanoic acid (APV). CA-, but not HCA-, mediated InsP formation was in part prevented by the metabotropic glutamate receptor antagonist alpha-methyl-4-carboxyphenylglycine ((+/-)-MCPG). Both HCA- and CA-mediated increases in intracellular calcium concentration were completely blocked by APV, but were not altered by (+/-)-MCPG. CA-mediated InsP formation was in part prevented by removal of endogenous glutamate. In contrast, the glutamate transport blocker L-aspartic acid-beta-hydroxamate synergistically increased CA responses. These data indicate that in cerebellar granule cells HCA mediates InsP formation wholly by activating NMDA receptor. In contrast, CA stimulates InsP formation by activating both NMDA receptor and metabotropic glutamate receptor, and in part by releasing endogenous glutamate into extracellular milieu.