Novel KV7 ion channel openers for the treatment of epilepsy and implications for detrusor tissue contraction

Neuronal voltage-gated potassium channels, K_V7s, are the molecular mediators of the M current and regulate membrane excitability in the central and peripheral neuronal systems. Herein, we report novel small molecule K_V7 openers that demonstrate anti-seizure activities in electroshock and pentylenetetrazol-induced seizure models without influencing Rotarod readouts in mice. The anti-seizure activity was determined to be proportional to the unbound concentration in the brain. K_V7 channels are also expressed in the bladder smooth muscle (detrusor) and activation of these channels may cause localized undesired effects. Therefore, the impact of individual K_V7 isoforms was investigated in human detrusor tissue using a panel of K_V7 openers with distinct activity profiles among K_V7 isoforms. KCNQ4 and KCNQ5 mRNA were highly expressed in detrusor tissue, yet a compound that has significantly reduced activity on homomeric K_V7.4 did not reduce detrusor contraction. This may suggest that the homomeric K_V7.4 channel plays a less significant role in bladder contraction and further investigation is needed.

Moderate maternal vitamin A deficiency alters myogenic regulatory protein expression and perinatal organ growth in the rat

Vitamin A deficiency is one of the most common dietary deficiencies in the developing world and is a major health concern where it is associated with increased risk of fetal and infant mortality and morbidity. Early studies in the rat demonstrated that, in addition to respiratory problems, neonates showed evidence of mobility problems in response to moderate vitamin A deficiency. This study investigated whether moderate deficiency of this vitamin plays a role in regulating key skeletal muscle regulatory pathways during development. Thirty female rats were fed vitamin A-moderate (VAM) or vitamin A-sufficient diets from weaning and throughout pregnancy. Fetal and neonatal hindlimb and muscle samples were collected on days 13.5, 15.5, 17.5, and 19.5 of pregnancy and 1 day following birth. Mothers fed the VAM diet had reduced retinol concentrations at all time points studied (P < 0.01), and neonates had reduced relative lung weights (P < 0.01). Fetal weight and survival did not differ between groups but neonatal survival was lower in the VAM group where neonates had increased relative heart weights (P < 0.05). Analysis of myogenic regulatory factor expression and calcineurin signaling in fetuses and neonates demonstrated decreased protein levels of myf5 [50% at 17.5 dg (P < 0.05)], myogenin [70% at birth (P < 0.001)], and myosin heavy chain fast [50% at birth (P < 0.05)] in response to moderate vitamin A deficiency. Overall, these changes suggest that vitamin A status during pregnancy may have important implications for fetal muscle development and subsequent muscle function in the offspring.

Stress plate optical modulator for circular dichroism measurements

The fused silica stress plate modulator described below offers several advantages over the other known electrooptic modulation devices: primarily, high transmission over a broad wavelength range, and large aperture. When operated at its electromechanical resonance frequency of 16.7 kHz, the modulator requires only low voltage, low power drive to operate as a +/-lambda/4 plate. Complete constructional details are given, including a model from which resonance frequencies may be calculated. As part of a circular dichroism apparatus, the modulator has allowed measurement of effects as small as 1 part in 10(5). The possibility of extension of the operating range into the vacuum uv is discussed.