The world's first wiki where authorship really matters (Nature Genetics, 2008). Due credit and reputation for authors. Imagine a global collaborative knowledge base for original thoughts. Search thousands of articles and collaborate with scientists around the globe.

wikigene or wiki gene protein drug chemical gene disease author authorship tracking collaborative publishing evolutionary knowledge reputation system wiki2.0 global collaboration genes proteins drugs chemicals diseases compound
Hoffmann, R. A wiki for the life sciences where authorship matters. Nature Genetics (2008)
 
 
 
 
 

ATP-dependent K+ channels modulate vasoconstrictor responses to severe hypoxia in isolated ferret lungs.

In normo- and hypoglycemic ferret lungs, the pulmonary vascular response to severe hypoxia (PiO2 less than or equal to 10 mmHg) is characterized by an initial intense vasoconstriction followed by marked vasodilation, whereas in hyperglycemic lungs, vasodilation is minimal, causing vasoconstriction to be sustained. In contrast, the response to moderate hypoxia is characterized by a slowly developing sustained vasoconstriction which is unaffected by glucose concentration. To determine the role of ATP-dependent K+ (KATP) channels in these responses, we examined the effects of cromakalim, which opens KATP channels, and glibenclamide, which closes them. During steady-state vasoconstriction induced in isolated ferret lungs by moderate hypoxia, cromakalim caused dose-dependent vasodilation (EC50 = 7 x 10(-7) M) which was reversed by glibenclamide (IC50 = 8 x 10(-7) M), indicating that KATP channels were present and capable of modulating vascular tone. During severe hypoxia in hypoglycemic lungs [( glucose] less than 1 mM), glibenclamide markedly inhibited the secondary vasodilation. Raising perfusate glucose concentration to 14 +/- 0.4 mM had the same effect. As a result, initial vasoconstrictor responses were well sustained. However, neither glibenclamide nor hyperglycemia affected vasoconstrictor responses to moderate hypoxia or KCl, indicating that effects during severe hypoxia were not due to nonspecific potentiation of vasoconstriction. These findings suggest that in the ferret lung (a) severe hypoxia decreased ATP concentration and thereby opened KATP channels, resulting in increased K+ efflux, hyperpolarization, vasodilation, and reversal of the initial vasoconstrictor response; and (b) hyperglycemia prevented this sequence of events.[1]

References

 
WikiGenes - Universities