These tools will no longer be maintained as of December 31, 2024. Archived website can be found here. PubMed4Hh GitHub repository can be found here. Contact NLM Customer Service if you have questions.


Pubmed for Handhelds

PUBMED FOR HANDHELDS

Search MEDLINE/PubMed

  • Title: Sodium-azide-evoked noradrenaline and catecholamine release from peripheral sympathetic nerves and chromaffin cells.
    Author: Török TL, Pauló T, Tóth PT, Azzidani AM, Powis DA, Magyar K.
    Journal: Gen Pharmacol; 1989; 20(2):143-9. PubMed ID: 2541042.
    Abstract:
    1. The spontaneous release of [3H]noradrenaline [( 3H]NA) has been measured from rabbit pulmonary arteries and bovine chromaffin cells in the presence of neuronal uptake blocker cocaine (3 x 10(-5) M). 2. The Na+-pump inhibitor sodium-azide (NaN3, 2mM) produced a moderate increase of [3H]NA release from both preparations and relaxed the arteries. The [3H]releasing action of NaN3 was accompanied by a 30% inhibition of 86Rb-uptake into chromaffin cells. 3. In both preparations, ouabain (10(-4) M) markedly increased the release of [3H], contracted the arteries and inhibited the 86Rb-uptake of chromaffin cells by about 75%. A combined application of NaN3 and ouabain produced a similar inhibition of 86Rb-uptake of chromaffin cells and failed to increase further the release of [3H] in comparison to that found in response to ouabain alone. 4. Removal of K+ from the external medium increased both the release of [3H]NA and the tone of pulmonary arteries. NaN3 further increased the transmitter release in "K+-free" solution but relaxed the muscle. In the absence of external K+ and in the presence of azide, ouabain further enhanced the transmitter release but failed to produce significant contraction. 5. Reactivation of the Na+-pump by readmission of K+ (5.9 mM) to the external medium abolished the transmitter releasing action of NaN3 in arteries. 6. It is concluded that in peripheral sympathetic nerves and chromaffin cells, NaN3 inhibits the Na+-pump producing NA and CA release respectively and in nerves even if NA release had already been increased by K+-removal.(ABSTRACT TRUNCATED AT 250 WORDS)
    [Abstract] [Full Text] [Related] [New Search]