Given a passage, construct a question on the basis of the information present in the passage. Construct the question in such a way that (i) it is unambiguous, (ii) it is answerable from the passage, (iii) its answer is unique (iv) it answer uses text phrases from the passage. Avoid creating questions that (i) can't be answered correctly without actually understanding the passage and (ii) uses the same words or phrases given in the passage.

Physiological roles of apelin and its specific receptor APJ signaling were investigated in vascular smooth muscle cells (VSMCs). The present study determined whether apelin activates myosin light chain (MLC), a major regulatory event in initiating smooth muscle contraction.', 'To assess MLC activation, we performed Western blot and immunohistochemical studies using an antibody against the phospho-MLC. In VSMCs, apelin induces the phosphorylation of MLC in a concentration-dependent manner with a peak at 2 minutes. Pretreatment of VSMCs with pertussis toxin abolishes the apelin-induced phosphorylation of MLC. Inhibition of protein kinase C (PKC) with GF-109203X markedly attenuated the apelin-induced MLC phosphorylation. In addition, methylisobutyl amiloride, a specific inhibitor of the Na+/H+ exchanger (NHE), and KB-R7943, a potent inhibitor for the reverse mode of the Na+/Ca2+ exchanger (NCX), significantly suppressed the action of apelin. In wild-type mice, apelin phosphorylates MLC in vascular tissue, whereas it had no response in APJ-deficient mice by Western blot and immunohistochemistry. Apelin-induced phosphorylation of MLC was accompanied with myosin phosphatase target subunit phosphorylation.
Does apelin stimulate myosin light chain phosphorylation in vascular smooth muscle cells?

It is a matter of debate whether or not ordinary heading of the ball in soccer causes injury to brain tissue.', 'To analyse concentrations of the biochemical markers of brain tissue damage S-100B and neurone specific enolase (NSE) in serum of female elite soccer players in association with a competitive game.', 'Venous blood samples were obtained from 44 female soccer players before and after a competitive game for analysis. The number of headers and trauma events (falls, collisions, etc) was assessed from videotape recordings for each player.', 'Concentrations of both brain damage markers were increased after the game (S-100B, 0.18 (0.11) v 0.11 (0.05) microg/l (p = 0.000); NSE, 10.14 (1.74) v 9.05 (1.59) microg/l (p = 0.001)). There was a significant correlation between changes in S-100B concentrations and both the number of headers (r = 0.430, p = 0.004) and the number of other trauma events (r = 0.517, p < 0.001).
Are serum concentrations of two biochemical markers of brain tissue damage S-100B and neurone specific enolase increased in elite female soccer players after a competitive game?

Topiramate is a novel anticonvulsant known to modulate the activity of several ligand- and voltage-gated ion channels in neurons. The mechanism of action of topiramate, at a molecular level, is still unclear, but the phosphorylation state of the channel/receptor seems to be a factor that is able to influence its activity. We investigated the consequences of phosphorylation of the sodium channel on the effect of topiramate on tetrodotoxin (TTX)-sensitive transient Na(+) current (I(NaT)).', 'I(NaT) was recorded in dissociated neurons of rat sensorimotor cortex using whole-cell patch-clamp configuration.', 'We found that topiramate (100 microM) significantly shifted the steady-state I(NaT) inactivation curve in a hyperpolarized direction. In neurons pre-treated with a PKC-activator, 1-oleoyl-2-acetyl-sn-glycerol (OAG; 2 microM), the net effect of topiramate on steady-state I(NaT) inactivation was significantly decreased. In addition, OAG also slightly shifted the I(NaT) activation curve in a hyperpolarized direction, while perfusion with topiramate had no effect on the parameters of I(NaT) activation.

Does phosphorylation of sodium channels mediated by protein kinase-C modulate inhibition by topiramate of tetrodotoxin-sensitive transient sodium current?