Maternal voluntary exercise ameliorates learning deficit in rat pups exposed, in utero, to valproic acid; role of BDNF and VEGF and their receptors

In utero exposure to therapeutic doses of valproic acid (VPA) during pregnancy can produce physical malformation and CNS abnormalities in the offspring. There is evidence indicating that even lower doses of VPA during pregnancy could cause cognitive impairment in offspring. It has been demonstrated that maternal exercise has positive effects on offspring's cognitive function. In this study we evaluated the preventive potential of maternal voluntary exercise on cognitive deficits induced by in utero exposure to VPA, in rat pups. Furthermore, the alteration of hippocampal brain-derived neurotrophic factor (BDNF) and vascular endothelial growth factor (VEGF) and their respective receptors were measured. In treatment groups, pregnant rats received VPA (10 and 20 mg/kg) daily on the gestation days (GD) 7 for twelve days with or without access to a running wheel. In control groups, rats received saline with or without access to a running wheel. On postnatal day (PND) 30, learning and memory of rat pups were assessed using the Morris Water Maze (MWM) task. Also, on PND 30, hippocampal BDNF and VEGF were measured by ELISA and western blot analysis respectively. VEGFR (VEGF receptor) and TrkB (Tyrosine receptor kinase B, the receptor for BDNF) expressions were assessed using immunofluorescence staining. Results revealed that maternal voluntary exercise enhanced learning in offspring but had little effect on memory retention. Exposure to VPA during pregnancy disturbed learning and memory in rat pups. Maternal voluntary exercise could ameliorate some aspects of cognitive deficit induced by VPA. TrkB and VEGFR2 expression were enhanced in pups from running mothers. VPA, at both doses, suppressed exercise induced expression of these two receptors. Voluntary exercise and to a much greater extent VPA administration increased hippocampal BDNF. Voluntary exercise of mothers caused an enhance expression of VEGF in rat pups as did VPA administration, although to a smaller amount.

Overview of ribosomal and non-ribosomal antimicrobial peptides produced by Gram positive bacteria

The increasing incidence of antimicrobial resistance bacterial infection and decreasing effectiveness of conventional antibiotics to treatment have caused serious problems worldwide. The demand for new generationantibiotics to combat microbial pathogens is imperative. Cationic antimicrobial peptides (AMPs) with different sources from prokaryotic to complex eukaryotic organisms, with variable length, amino acid composition and secondary structure, have been consideredduring the past decades.  The advantages of large number of AMPs are related to broad spectrum and morphogenetic activities, low resistance rate among microorganismswithout side effect on human cells, rapid killing of bacteria via membrane damage and intracellular targets,and their critical roles in anti-inflammatory. Ribosomal synthesized peptides of Gram positive bacteria with various post translational modificationsrepresent extended types of antimicrobial peptide with different structural and functional diversity. These types of peptides have been considered as new therapeutic agents for pharmaceutical development .In addition, non- ribosomal synthesized peptides are a wide range of peptides , an extremely extensive range of biological activities and pharmacological properties that are not synthesized by ribosomes,  show interesting biological properties ranging from antibiotic to bio surfactants. This review focused on genetics, mechanism of action and modifications, resistance mode of Gram positive bacteria to AMPs and the biotechnological application of ribosomally and non-ribosomally synthesized peptides derived from Gram positive bacteria.

Serotonergic and noradrenergic lesions suppress the enhancing effect of maternal exercise during pregnancy on learning and memory in rat pups

The beneficial effects of exercise on learning and memory are well documented but the effects of prenatal exposure to maternal exercise on offspring are not clear yet. Using a two-trial-per-day Morris water maze for five consecutive days, succeeded by a probe trial 2 days later we showed that maternal voluntary exercise (wheel running) by pregnant rats increased the acquisition phase of the pups' learning. Maternal forced swimming by pregnant rats increased both acquisition and retention phases of the pups' learning. Also we found that the rat pups whose mother was submitted to forced-swimming during pregnancy had significantly higher brain, liver, heart and kidney weights compared with their sedentary counterparts. On the other hand we estimated the cell number of different regions of the hippocampus in the rat pups. We found that both exercise models during pregnancy increased the cell number in cornus ammonis subregion 1 (CA1) and dentate gyrus of the hippocampus in rat pups. To determine the role that noradrenergic and serotonergic neurotransmission and N-methyl-D-aspartate (NMDA) receptors hold in mediation of the maternal exercise in offspring, we used N-(2-chloroethyl)-N-ethyl-2-bromobenzylamine (DSP-4), p-chloroamphetamine (PCA) and MK-801 to eliminate or block the above systems, respectively. Blocking the NMDA receptors, significantly abolished learning and memory in rat pups from all three experimental groups. Elimination of noradrenergic or serotonergic input did not significantly attenuate the learning and memory in rat pups whose mothers were sedentary, while it significantly reversed the positive effects of maternal exercise during pregnancy on rat pups' learning and memory. The presented results suggest that noradrenergic and serotonergic systems in offspring brain seem to have a crucial specific role in mediating the effects of maternal physical activity during pregnancy on rat pups' cognitive function in both models of voluntary and forced exercise.

Effects of diltiazem and verapamil on ADP-induced rabbit platelet shape change and aggregation

1. The effects of diltiazem and verapamil (two structurally different calcium channel blockers) were examined on the rabbit platelets shape change and aggregation induced by adenosine-5'-diphosphate (ADP). 2. ADP was a much more potent stimulator on inducing platelet shape change (ED50 = 1 x 10(-7)) than platelet aggregation (ED50 = 1.78 x 10(-6)). 3. Both drugs similarly inhibited ADP-induced platelet shape change and aggregation at concentrations more than 300 microM. 4. There were no significant differences in inhibitory effects of either diltiazem or verapamil on ADP-induced platelet shape change and aggregation. 5. The inhibitory effects of diltiazem and verapamil on ADP-induced platelet shape change and aggregation at high concentrations may be due to their non specific properties.