someone please answer this..

[jfgavina]

Advertisement - Members don't see this ad

this may be a very simple concept but I need some clarification.

why does epinephrine increase systolic blood pressure and at the same time decrease diastolic blood pressure and renal blood flow?

in FA it is listed that epinephrine acts w/ the same affinity to all receptors, so why the hell does it decrease diastolic blood flow (I suppose that it acts w/ same affinity to alpha and beta-2) and renal blood flow (I suppose it acts w/ same affinity to D-1 and alpha-1)




thanks a lot people

 

[norealname]

The level of systolic blood pressure is mainly controlled by cardiac output, while the diastolic blood pressure is mainly controlled by total peripheral resistance.
As far as I remember, epinephrine mainly acts on the beta-receptors at low-moderate doses, and only starts to have an effect on alpha1-receptors at high doses.

At moderate epinephrine doses, there is major beta-adrenergic activation. Your beta1 activation will increase cardiac output, so systolic bp goes up. Also, beta2 activation will reduce total peripheral resistance, and so your diastolic bp will fall. This will also cause widening of the pulse pressure.

 

[jfgavina]

simple, clear and good.

thanks no real name