Parm Question

[swanguy]

Wondering if someone might enlighten me, I am preparing for an interview and have a couple pharm questions I can't seem to find answers to yet.

1) When dopamine stimulates D1 receptors in the renal vasculature it causes vasodilation, however the mechanism of Increasing cAMP and intracellular calcium is the exact same as say stimulating B1 receptors in the heart that leads to increased intracellular calcium, and therefore an increased contraction. To clarify, my question is why does increased intracellular calcium (after D1 receptor stimulation) in the renal arteries cause vasodialtion instead of vasoconstriction like other areas of the body when calcium is increased intracellularly?

2)Are D2 receptors stimulated the same time D1 receptors are and just counteract D1? (D1 stimulates adenlyly cyclase, D2 inhibits adenylyl cyclase correct?)

Any help is appreciated, thanks.

[SproutRN]

Wondering if someone might enlighten me, I am preparing for an interview and have a couple pharm questions I can't seem to find answers to yet.

1) When dopamine stimulates D1 receptors in the renal vasculature it causes vasodilation, however the mechanism of Increasing cAMP and intracellular calcium is the exact same as say stimulating B1 receptors in the heart that leads to increased intracellular calcium, and therefore an increased contraction. To clarify, my question is why does increased intracellular calcium (after D1 receptor stimulation) in the renal arteries cause vasodialtion instead of vasoconstriction like other areas of the body when calcium is increased intracellularly?

2)Are D2 receptors stimulated the same time D1 receptors are and just counteract D1? (D1 stimulates adenlyly cyclase, D2 inhibits adenylyl cyclase correct?)

Any help is appreciated, thanks.

If my memory serves me correctly cAMP acts differently in certain areas of the body....just as you described. I believe it also causes bronchodilation in the lungs. Anywhooo.....sorry that wasn't much help.

I don't think I'd stress too much over that topic. That is an indepth discussion that will be brought up in your biochem and pharmacology classes. I can't imagine you having a question that in depth during your interview. When I was interviewed I discussed the differences of dopamine and dobutamine. What school is your interview with?

SproutCRNA

[swanguy]

Thanks, I interview with MTSA.

[ltk007]

cAMP is a second messenger, and second messengers have "cell-specific" effects; the increase in Ca++ in one cell doesn't necessarily mean that this is true in other cellular environments.

[NICU_RN_CN]

You have to be careful answering interview questions with elaborate answers. I know you want to make a good impression but, it usually doesn't make you look any smarter and you will be asked about things you cant prepare for or even begin to explain. They want to see you under a little pressure. At least that's the way it is when I sit in on interviews now.

[swanguy]

Thanks to all who replied. I was only studying this material, because MTSA ask you specifically about the mechanism of action of drugs at the cellular level. They expect you to know what you currently use in the ICU. Anyway, the interview went great, and I got in. Thanks to everyone who uses this board. I have followed it for several years and it has given me a lot of helpful information.