Behavioral effects of Bj-PRO-7a, a proline-rich oligopeptide from Bothrops jararaca venom

The heptapeptide Bj-PRO-7a, isolated and identified from Bothrops jararaca (Bj) venom, produces antihypertensive and other cardiovascular effects that are independent on angiotensin converting enzyme inhibition, possibly relying on cholinergic muscarinic receptors subtype 1 (M1R). However, whether Bj-PRO-7a acts upon the central nervous system and modifies behavior is yet to be determined. Therefore, the aims of this study were: i) to assess the effects of acute administration of Bj-PRO-7a upon behavior; ii) to reveal mechanisms involved in the effects of Bj-PRO-7a upon locomotion/exploration, anxiety, and depression-like behaviors. For this purpose, adult male Wistar (WT, wild type) and spontaneous hypertensive rats (SHR) received intraperitoneal injections of vehicle (0.9% NaCl), diazepam (2 mg/kg), imipramine (15 mg/kg), Bj-PRO-7a (71, 213 or 426 nmol/kg), pirenzepine (852 nmol/kg), α-methyl-DL-tyrosine (200 mg/kg), or chlorpromazine (2 mg/kg), and underwent elevated plus maze, open field, and forced swimming tests. The heptapeptide promoted anxiolytic and antidepressant-like effects and increased locomotion/exploration. These effects of Bj-PRO-7a seem to be dependent on M1R activation and dopaminergic receptors and rely on catecholaminergic pathways.

Inhibition of Trypanosoma cruzi proline racemase affects host-parasite interactions and the outcome of in vitro infection

Proline racemase is an important enzyme of Trypanosoma cruzi and has been shown to be an effective mitogen for B cells, thus contributing to the parasite's immune evasion and persistence in the human host. Recombinant epimastigote parasites overexpressing TcPRAC genes coding for proline racemase present an augmented ability to differentiate into metacyclic infective forms and subsequently penetrate host-cells in vitro. Here we demonstrate that both anti T. cruzi proline racemase antibodies and the specific proline racemase inhibitor pyrrole-2-carboxylic acid significantly affect parasite infection of Vero cells in vitro. This inhibitor also hampers T. cruzi intracellular differentiation.

Lipoproteína A, "el colesterol malísimo" / A lipoprotein

La hiperlipidemia por lipoproteína a -LDL más apo a- es un factor de riesgo vascular aterotrombótico, familiar, independiente y poderoso, llamativamente desconsiderado. Este trabajo tiene como objetivo su mejor diagnóstico y tratamiento.

Hidrolisado de colageno: utilizacao biologica em misturas proteicas e seu efeito no tecido cutaneo / Hidrolised collagen: biological utilization in proteics mix and its effect in cutaneous tissue

Estudou-se a adicao de hidrolisado de colageno a racoes com caseina nas proporcoes de 0 por cento, 25 por cento, 50 por cento, 65 por cento, 75 por cento e 100 por cento. As racoes com 25 por cento e 65 por cento de hidrolisado proteico foram acrescidas com prolina e aminoacidos essenciais (tirosina, triptofano, metionina e leucina). As reacoes continham 10 por cento e 20 por cento de proteina. Determinou-se o coeficiente de eficacia proteica, coeficiente de digestibilidade, composicao centesimal, aminograma e avaliou-se histologicamente o figado e rim e a pele. Doseou-se o teor de hidroxiprolina da pele dos animais testados. Verificou-se que: a adicao de 25 por cento de hidrolisado de colageno a caseina nao promoveu modificacao significativa no valor biologico da racao. A adicao de prolina em racao com 25 por cento de colageno para ratos em crescimento nao demonstrou alteracao do peso dos animais. Entretanto com adicao de 65 por cento de colageno houve queda no peso dos animais em relacao ao controle. O figado dos animais estudados (quando utilizados racoes com 10 por cento de proteina), nao demonstrou alteracao significativa em relacao as diferentes adicoes de colageno. Quando a racao foi acrescida de 50 porcento e 65 por cento de hidrolisado de colageno, o doseamento de hidroxiprolina na pele aumentou e os cortes histologicos de tecido cutaneo apresentaram ausencia de hipoderme

Role of media constituents and proline in callus growth, somatic embryogenesis and regeneration of Oryza sativa cv Indica.

Conditions were optimised for efficient callus induction from seeds of four local indica rice cultivars, GR-3, GR-102, Jaya and Te-Tep. Addition of 2,4-D to MS medium at 2.5 mg/l resulted in 100% callus induction. N6 medium was superior to MS medium for callus growth, formation of embryogenic callus as well as regeneration. Cultivar Te-Tep showed highest callus growth while GR-102 the least. Addition of casein hydrolysate enhanced growth of callus but did not yield more embryogenic calli. Supplementation of MS or N6 media with proline, not only increased callus growth but also showed an increase in embryogenic callus formation. GR-102 callus was most embryogenic followed by Te-Tep, GR-3 and Jaya. Histological observation of embryogenic calli revealed the presence of pro-embryo like structures. It was also observed that calli induced on N6 medium supplemented with proline could maintain regeneration potential for a longer period as compared to other media. Cytokinins like BAP or kinetin alone could not initiate shoot formation. Regeneration frequency, and the number of shoots formed per callus increased significantly. Cultivar Te-Tep gave the best response for regeneration followed by Jaya, GR-3 and GR-102.