Step I How does histamine cause vasodilation?

[whatdidigetinto]

What's the mechanism?

 

[loveoforganic2]

H2 receptor is on vascular smooth muscle (Gs coupled)

 

[medpack87]

H2 receptor is on vascular smooth muscle (Gs coupled)

Yes.

 

[CaptainSSO]

http://www.ncbi.nlm.nih.gov/m/pubmed/8151062/?i=2&from=/7628185/related

 

[whatdidigetinto]

Thanks guys. So basically histamine acts on H1 receptors to increase vascular permeability, and acts on h2 receptors to vasodilate?

 

[Zzmed]

H2: smooth muscle relaxation (Gs)
H1: systemic vasodilation (Gq)

all these from Wiki.

In pharm I have been taught: H1+H2: dilation and increased permeability of capillaries