Figure 9: Hyperpolarization of SMC by yellow light activation can ameliorate PGE2-induced overactivity of NpHR-bladder.
From: Optogenetic Modulation of Urinary Bladder Contraction for Lower Urinary Tract Dysfunction
NpHR-bladder was produced transgenically (Fig. 1a) and subjected to patch clamp test (Fig. 2a) and ex vivo evaluation (Fig. 3a). (a) Representative traces of membrane potential changes of NpHR-SMCs evoked by yellow light (589 nm) stimulation at 0.006, 0.06, 0.6, 6, and 16 mW/mm2 (left). Yellow bar indicates yellow illumination for 1 s. Membrane potential changes evoked by yellow light were strongly dependent upon yellow light intensity (right, n = 5). (b) PGE2 (50 μM) treatment induced an overactive bladder indicated by increase of spontaneous bladder contraction. The spontaneous bladder contraction was suppressed by yellow light (189 mW) illumination for 60 s. (c) Average pressure changes of the NpHR-bladder were compared between the bladders with PGE2 treatment and with PGE2 treatment and yellow light illumination (n = 5). Average pressure change was measured with respect to the average intravesical pressure of bladder sample prior to the PGE2 treatment. Yellow light significantly reduced the increased bladder pressure evoked by PGE2 treatment (p < 0.01, repeated measures ANOVA n = 5). All error bars indicate SE.
