Reduced urinary excretion of sulfated polysaccharides in diabetic rats

The aim of the present study was to further understand the changes in renal filtration that occur in the early stages of diabetes mellitus. Diabetes was induced in male Wistar rats by a single injection of streptozotocin. Glycemia, body weight, 24-h urine volume and urinary excretion of creatinine, protein and glycosaminoglycans were measured 10 and 30 days after diabetes induction. All the diabetic animals used in the present study were hyperglycemic, did not gain weight, and presented proteinuria and creatinine hyperfiltration. In contrast, the glycosaminoglycan excretion decreased. Dextran sulfates of different molecular weights (6.0 to 11.5 kDa) were administered to the diabetic rats, and to age-matched, sham-treated controls. Most of the dextran sulfate was excreted during the first 24 h, and the amounts excreted in the urine were inversely proportional to the dextran sulfate molecular weight for all groups. Nevertheless, diabetic rats excreted less and accumulated more dextran sulfate in kidney and liver, as compared to controls. These differences, which were observed only for the dextran sulfates of higher molecular weights (>7 kDa), increased with the duration of diabetes. Our findings suggest differential renal processing mechanisms for proteins and sulfated polysaccharides, with the possible involvement of kidney cells.     

Effect of goniothalamin on the development of Ehrlich solid tumor in mice

In this work the antiproliferative activity of goniothalamin (1), both in racemic and in its enantiomeric pure forms, in a solid tumor experimental model using laboratory animals is described. The antiedematogenic activity displayed by racemic 1 in the carrageenan edema model in mice together with the reduction of Ehrlich solid tumor model suggest a relationship between anticancer and antiinflammatory activities with the antiinflammatory activity favoring the antiproliferative activity itself.     

Mercury Exposure: Protein Biomarkers of Mercury Exposure in Jaraqui Fish from the Amazon Region

Poly-trans-[(2-carboxyethyl)germasesquioxane] (Ge-132) is a water-soluble organogermanium compound that exerts various physiological effects, including anti-inflammatory activity and pain relief. In water, Ge-132 is hydrolyzed to 3-(trihydroxygermyl)propanoic acid (THGP), which in turn is capable of interacting with cis-diol compounds through its trihydroxy group, indicating that this compound could also interact with diol-containing nucleic acid constituents. In this study, we evaluated the ability of THGP to interact with nucleosides or nucleotides via nuclear magnetic resonance (NMR) analysis. In addition, we evaluated the effect of added THGP on the enzymatic activity of adenosine deaminase (ADA) when using adenosine or 2′-deoxyadenosine as a substrate. In solution, THGP indeed formed complexes with nucleotides or nucleosides through their cis-diol group. Moreover, the ability of THGP to form complexes with nucleotides was influenced by the number of phosphate groups present on the ribose moiety. Notably, THGP also inhibited the catalysis of adenosine by ADA in a concentration-dependent manner. Thus, interactions between THGP and important biological nucleic acid constituents might be implicated in the physiological effects of Ge-132.     

Asymmetric total synthesis and antiproliferative activity of goniothalamin oxide isomers

Goniothalamin oxide (1) is a styryl lactone which was isolated from bark and leaves of several Goniothalamus species. This natural product has some interesting biological properties such as larvicidal and tripanocidal activities. However, no studies on the antiproliferative profile of goniothalamin oxide (1) and its stereoisomers have been reported yet. Here, goniothalamin epoxide (1), isogoniothalamin epoxide (2) and their enantiomers were prepared via epoxidation of (R)-and (S)-goniothalamin (4). A 3:2 molar ratio in favor of goniothalamin oxide (1) and ent-1 was observed from (R)- and (S)-4, respectively, when 3-chloroperbenzoic acid (mCPBA) was employed while an increase to 6:1 molar ratio was achieved with (S,S)-Jacobsen’s catalyst. Antiproliferative activity of these epoxides revealed that ent-isogoniothalamin oxide (ent-2) was the most active against the eight cancer cell lines studied. These results indicate that 6S, 7R and 8R absolute configurations are beneficial for the activity of these epoxides.     

A Preliminary and Qualitative Metallomics Study of Mercury in the Muscle of Fish from Amazonas, Brazil

In this study, we report the effect of zinc supplementation on the distribution of elements in kidney tissue of diabetic rats subjected to acute swimming exercise. Diabetes was induced by two subcutaneous injections of 40 mg/kg of streptozotocin within a 24-h period. Zinc was given intraperitoneally at a dose of 6 mg/kg per day for a period of 4 weeks. The rats (n = 80) were equally divided into eight study groups: controls, zinc-supplemented, swimming, diabetic, zinc-supplemented diabetic, zinc-supplemented swimming, diabetic swimming, and zinc-supplemented diabetic swimming. The levels of lead, cobalt, molybdenum, chromium, boron, magnesium, iron, copper, calcium, zinc, and selenium were determined in the kidney tissue samples by ICP-AES. Higher molybdenum, calcium, zinc, and selenium values were found in both swimming and nonswimming diabetic rats. Significantly higher iron values were found in swimming, diabetic, diabetic swimming, and zinc-supplemented diabetic swimming rats (p < 0.001). Diabetic, zinc-supplemented diabetic, diabetic swimming, and zinc-supplemented diabetic swimming rats had the highest copper values. These results show that zinc supplementation normalized the higher levels of molybdenum, calcium, selenium, and iron levels seen in diabetic rats, indicating that zinc may have a regulatory effect on element metabolism in kidney tissue.     

Midazolam and theN-methyl-d-aspartate (NMDA) receptor antagonist 2-amino-7-phosphonoheptanoic acid (AP-7) attenuate stress-induced expression of c-fos mRNA in the dentate gyrus

Summary 1. The effects of restraint stress on c-fos mRNA expression in the dentate gyrus were investigated byin situ hybridization.2. Confirming previous findings, c-fos mRNA expression increased after 30 min of forced restraint.3. This effect was attenuated by a previous i.c.v. injection of the anxiolytic benzodiazepine midazolam (20 nmol/2 µl) or theN-methyl-d-aspartate (NMDA) receptor antagonist 2-amino-7-phosphonoheptanoic acid (AP-7; 5 nmol/2 µl).4. These results suggest that the dentate gyrus is activated during restraint stress and that this activation may be modulated by benzodiazepine -aminobutyric acid_A (GABA_A) or NMDA receptors.     

The peeping response of pigeons (Columba livia) to isolation from conspecifics and exposure to a novel environment

The present study examined the acute behavioral responses of pigeons to separation from conspecifics and exposure to an unfamiliar environment (UE). The effects of (1) repeated exposure to the UE; (2) visual isolation from surroundings, or saline injections; and (3) diazepam treatment (i.p., 0.25, 0.75, 2.5 or 7.5 mg/kg) before the trial were also examined. UE exposure evoked intense ballistic head movements (peeping), gradually replaced with angular head movements (AHM), both associated with immobility of the trunk and legs. These behaviors failed to habituate after three trials (7-day intertrial intervals). Visual isolation from the surroundings and saline injection prior to exposure to the UE increased the AHM and reduced peeping. Doses of diazepam (0.25 and 0.75 mg/kg) that have demonstrated anti-conflict effects in other tests did not affect the behavioral responses to the UE. Diazepam at 2.5 and 7.5 mg/kg doses consistently increased time spent in immobility. These data suggest that peeping, although expressed in potentially threatening or harmful situations appears not to be a fear-motivated behavior or, alternatively, this specific behavioral response is not diazepam sensitive.