D1 receptors & renal vascular smooth muscle?

[WhoisJohnGalt]

I'm looking at FA (in 2006, it's pages 198 & 199), and it says that D1 receptors receive sympathetic output and are responsible for relaxing renal vascular smooth muscle.

My question is, I don't really see how that fits in with fight or flight. I thought that splanchnic organs were supposed to be vasoconstricted so you could shunt your blood to your heart and muscles? It just doesn't really seem to be a good idea to be worried about your kidneys when you're being attacked by the bear. Thanks for any enlightenment you all can offer!

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[lord_jeebus]

I think it is believed that the renal dopamine receptors' primary function involves dopamine produced locally by the kidneys to regulate sodium excretion. I don't think the details of this are fully understood and I don't think you would be expected to know much beyond the fact that these receptors exist and relax vascular SM.

 

[Blues_Rider]

There is increasing evidence that the intrarenal dopaminergic system plays an important role in the regulation of blood pressure. See http://rd.springer.com/article/10.1007/s11906-012-0253-z

You may also be interested in the article "Renal function and genetic variation in dopamine D1 receptor: is the case strong enough?" (http://www.nature.com/ki/journal/v76/n10/full/ki2009328a.html) which claims "The role of dopamine and its receptors in determination of blood pressure has been well established; dopamine regulates vascular smooth muscle contractility and renal sodium transport." with the reference = Wang X, Villar VAM, Armando I et al. Dopamine, kidney, and hypertension: studies in dopamine receptor knockout mice. Pediatr Nephrol 2008; 23: 2131–2146.

 

[Thrombophlebitis]

Are you actually replying to a question that was asked more than 8 years ago?

 

[Dr Cat]

Thank you for your answer Blues Rider. There isn't a whole lot of information on this mechanism and those two articles are very helpful. These threads are permanent and even 10 years later people are still asking the same questions (like me), and the information is definitely evolving. Thank you!!

 

[bumblebee611]

Are you actually replying to a question that was asked more than 8 years ago?

I'm with @Dr Cat. I just Googled this question (after seeing it in First Aid) and found this lovely answer!