Regulation of Na+/H+ Exchanger by Urogastrone, a Potent Activator of Cell Proliferation

Title:

Regulation of Na+/H+ Exchanger by Urogastrone, a Potent Activator of Cell Proliferation

Creator:

Barišić, K., Karužić, O., Petrik, J., and Grubišić, T. Ž.

Identifier:

https://cdk.lib.cas.cz/client/handle/uuid:12b3b06b-d4f1-4ddd-b6c4-b026256c7bbd
uuid:12b3b06b-d4f1-4ddd-b6c4-b026256c7bbd
issn:0862-8408

Subject:

Fyziologie člověka a srovnávací fyziologie, fyziologie člověka, human physiology, Na+/H+ exchanger, Kidney brush border membrane vesicles, Epidermal growth factor, Urogastrone, 14, and 612

Type:

article, studie, model:article, and TEXT

Format:

print, bez média, and svazek

Description:

We tested the effects of epidermal growth factor (EGF) on Na+/H+ exchanger (NHE) activity using urogastrone for treatment of Wistar rats and rat kidney tissue slices. NHE activity was monitored in isolated kidney brush border membrane vesicles by following fluorescence quenching of acridine orange. A significant increase of NHE activity was detected as early as 5 min after addition of urogastrone to rat kidney slices in vitro. In Wistar rats treated with urogastrone we also found increased NHE activity (by about 12 %). Both changes of NHE activity were the result of a significant rise of Vmax value and an apparent decrease in Km value in in vitro experiments. The rise of NHE activity caused by urogastrone was sensitive to the inhibitors of transcription and translation. The presence of phosphatase inhibitor, NaF, elevated NHE activity of non-stimulated as well as of urogastrone-stimulated exchanger, suggesting that phosphorylation plays an important role in Na+/H+ exchange. Osmolarity of the medium seems to regulate NHE activity in such a manner that both hyper- and hypoosmolar conditions inhibited NHE activity. The absence of Ca2+ions produced a 60 % decrease of NHE activity. The chemical modification of histidine residues with diethyl pyrocarbonate or SH groups with N-ethylmaleimide inhibited NHE activity., K. Barišić, O. Karužić, J. Petrik, T. Ž. Grubišić., and Obsahuje bibliografii

Language:

English

Rights:

http://creativecommons.org/licenses/by-nc-sa/4.0/
policy:public

Source:

Physiological research | 2002 Volume:51 | Number:5

Harvested from:

CDK

Metadata only:

false