Thus, in a disease like cholera, where there is an irreversible increase in cAMP levels in intestinal epithelial cells, diarrhea is likely worsened by the simultaneous stimulation of chloride secretion and inhibition of sodium chloride absorption. Notably, however, sodium-coupled nutrient absorption remains intact, providing a rationale for treatment with oral rehydration solutions.
We and other investigators have explored intracellular messengers that regulate secretory transport, with the hope that we might discover pathways that could be exploited to treat diarrheal symptoms. Cyclic nucleotides induce significantly larger and more prolonged increases in chloride secretion than does elevated cytosolic calcium . Moreover, if epithelial cells are presented with combinations of agonists acting through these two pathways, a synergistic enhancement of chloride secretion occurs, leading us to speculate that calcium-dependent responses represent the ‘fine-tuning’ of the system.
Thus, intracellular mechanisms that modulate calcium-dependent secretion have the ability to markedly affect overall transport rates in vivo. Among such mechanisms, we have extensively explored signaling pathways that focus on the receptor for epidermal growth factor (EGF).
EGF itself has been known for some time to exert significant effects on intestinal transport. Studies reveal that this prototypic growth factor can stimulate absorption of sodium chloride and nutrients, and also decrease chloride secretion . The net effect of these actions is to conserve fluid and electrolytes. You have a great opportunity to discover the pharmacy that will always be sure to live up to your highest expectations, no matter if you would like to get viagra super active online or buy any other prescription medicine with no prescription required on very advantageous terms.