English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Tools annual

Global: Zendy Free Plan

Global: Zendy Tools monthly

Global: Zendy Plus monthly

The influence of norepinephrine on the diameter of single pial arteries and arterioles was investigated by adding the drug to the perivascular space with micropipettes. The mock spinal fluid solution in which the norepinephrine was dissolved contained 0, 11, or 22 mEq/liter of bicarbonate. These concentrations of bicarbonate were by themselves found to dilate, cause no change, and constrict the pial vessels, respectively. Concentration-response curves with 11 mEq/liter of bicarbonate over the concentration range of 5 × 10−4 to 5 mmoles/liter of norepinephrine showed significant constriction at 5 × 10−2 mmoles/liter and maximal constriction (40% of diameter) at 2.5 mmoles/liter. In bicarbonate-free solution, the slope of the concentration-response curves was less, and at 22 mEq/liter of bicarbonate norepinephrine had no effect. The pial arteries seemed to be less sensitive than the mesenteric and the cremasteric arteries to norepinephrine. The present data demonstrate the existence of norepinephrine receptors on the pial arterial smooth muscle cells, which satisfies the major requirement for the possible existence of a sympathetic control of cerebral blood flow.

Effect of I-Norepinephrine on the Diameter of Pial Arterioles and Arteries in the Cat