acetylcholine and blood pressure

Prep for USMLE Forum

» Log in | Register

Forum

Step 1

Match

Prep4USMLE Forum » USMLE Step 1 Forum » Pharmacology Forum

acetylcholine and blood pressure

Author

4 Posts

peekay
Forum Guru

Topics: 102
Posts: 588

03/27/04 - 02:42 AM

we know that there is no parasympathetic innervtion of the blood vessels but when acetylcholine is given( a direct acting cholinergic agonist) there is drop in b.p by what mechanism

mistral92
Forum Senior

Topics: 4
Posts: 185

03/27/04 - 05:37 AM

Action of acetyl choline mimic the action of vagal nerve stimulation.
there is no parasympathic stimulation BUT there are cholinergic receptors on the blood vessels that respond by causing vasodilation... this is due to an acetyl cholin- induced rise in intracellular CALCIUM caused by the phosphatidyl inositol system that results in the formation of NO from arginine in the endothelial cells (EDRF)...vasodilation occurs.
decrease of HEART rate and stroke volume results from reduction of the firing at the sinoatrial node.

usmleasr
Forum Guru

Topics: 105
Posts: 970

03/27/04 - 09:29 AM

yes it is..only indirect acting sympathomimetics have no effect on blood vessels

peekay
Forum Guru

Topics: 102
Posts: 588

03/27/04 - 04:57 PM

good reasoning mistral92.you are correct

You don't have permission to post.