Effect of scapular posterior tilting exercise on scapular muscle activities in men and women with a rounded shoulder posture.

Round-shoulder posture (RSP) is a common postural condition, characterized by protraction, downward rotation, anterior tilting and internal rotation of the scapula. RSP can lead to shoulder dysfunction. Different methods have been proposed for rehabilitating and correcting the altered posture in RSP including stretching, strengthening exercises, and shoulder brace or taping. However, the findings are controversial and studies are ongoing to develop more effective method. The present study is aimed at investigating the effects of scapular posterior tilting (SPT) exercise in different support positions on scapular muscle activities in men and women with RSP. In a prospective observational clinical study, we assessed demographic, basic clinical parameters and study variables of the subjects with RSP (n = 20) (men/women = 9/11) attending Daegu University in Gyeongsan, South Korea. To do so, we compared electromyographic (EMG) activities of lower trapezius and serratus anterior muscles between men and women with RSP during SPT exercise on four different support surfaces to determine any difference in the EMG activities. The results revealed that women showed significant differences in EMG activities in the lower and left upper trapezius and serratus anterior muscles, while men showed significant differences in EMG activity only in the lower trapezius muscle during SPT exercise on four different surfaces (P < 0.05). The post-hoc analysis revealed significantly greater EMG activity values in the lower trapezius and serratus anterior muscles during SPT exercise on the upper body unstable surface and whole-body unstable surface (p < 0.05). Independent t-tests after the Bonferroni correction showed no significant differences in muscle activities between men and women on the four different surfaces (p > 0.0125).

Hypoxia reduces testosterone synthesis in mouse Leydig cells by inhibiting NRF1-activated StAR expression.

Male fertility disorders play a key role in half of all infertility cases. Reduction in testosterone induced by hypoxia might cause diseases in reproductive system and other organs. Hypoxic exposure caused a significant decrease of NRF1. Software analysis reported that the promoter region of steroidogenic acute regulatory protein (StAR) contained NRF1 binding sites, indicating NRF1 promoted testicular steroidogenesis. The purpose of this study is to determine NRF1 is involved in testosterone synthesis; and under hypoxia, the decrease of testosterone synthesis is caused by lower expression of NRF1. We designed both in vivo and in vitro experiments. Under hypoxia, the expressions of NRF1 in Leydig cells and testosterone level were significantly decreased both in vivo and in vitro. Overexpression and interference NRF1 could induced StAR and testosterone increased and decreased respectively. ChIP results confirmed the binding of NRF1 to StAR promoter region. In conclusion, decline of NRF1 expression downregulated the level of StAR, which ultimately resulted in a reduction in testosterone synthesis.

TRPC6 inhibited NMDA current in cultured hippocampal neurons.

N-methyl-D-aspartate (NMDA) receptors play a key role in excitatory synaptic transmission, plasticity and neural development, and they also mediate excitotoxicity that is involved in both acute neuronal damage and chronic neurodegenerative diseases. Regulation of the NMDA channel activity is critical for the pathological processes of these diseases. The canonical transient receptor potential channels (TRPCs) are Ca(2+)-permeable nonselective cation channels with various physiological functions, including promoting neuronal survival. Here, we reported that TRPC6, a member of the TRPC family, inhibited the NMDA-induced current in primary cultured hippocampal neurons. Overexpression of TRPC6 or application of 1-oleoyl-2-acetyl-sn-glycerol, a compound known to activate TRPCs, inhibited the NMDA-induced current in these neurons assayed by the whole-cell patch-clamp recording. Consistently, downregulation of TRPC6 or application of SKF96365, a compound known to inhibit TRPCs, enhanced this current. The peak amplitude of the NMDA current in the neurons isolated from TRPC6 transgenic mice was greatly suppressed than that in the neurons isolated from the wild-type littermates. Furthermore, TRPC6 might activate calcineurin to inhibit the activity of NMDA receptors in cultured hippocampal neurons. Together, these results suggested that TRPC6 might be a novel negative modulator of NMDA receptors.