Receptor desensitization happens on a scale of minutes, while AC superactivation is the result of much longer term chronic receptor activation.
Although a lower concentration of H2O2 is used in the latter, its protective effect may be due to a much longer treatment time as the activation of protective signaling by ROS accumulates with time.
In addition, the pharmacodynamic half-life of drugs that change receptor activation levels is much longer than the tens of seconds the network activity is sustained.
The long-chain branched polycarbonates exhibit higher zero-shear viscosities, more significant shear shinning, higher flow activation energies, and much longer relaxation times.
Consistent with this model we find that male gametogenesis started to become insensitive to dantrolene within seconds of activation, but remained sensitive to U73122 for a much longer period (Fig. 5D).
In fact, it has been reported that mβCD induces COX-2 epression and activation in a macrophage cell line, but at a much longer incubation time [53].
Additionally, the activation of Rac1 lasted up to 120 min, and this is much longer than that of RhoA, which returned to its basal level in 30 min.
Owing to the multiple layers of genetic cascades within these intercellular systems, much longer response time might be needed for synthesizing the signalling molecules to achieve efficient cell communication and activation of the downstream genetic modules.
It is envisioned that activation of Nrf2 by this p62-dependent, but Keap1 cysteine-independent mechanism takes a much longer time to attenuate, which leads to heightened cell survival and potential cellular transformation.
Whereas the first two steps are transport-limited, the two latter processes involve large activation energies related to micellar fusion against the sterically stabilizing micellar coronas, which corresponds to much longer time scales of self-assembly.
