Bronchodilators Part 2: Mechanisms of Action

We just introduced the concept of bronchodilators, so we know what they are, and their intended targets. But what are the mechanisms by which these drugs interact with beta-2 adrenoceptors and muscarinic receptors? What are the signaling pathways that mediate their effects? Let's get a closer look!
Script by Michael Keith
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[@glennpearson9348]

I have to admit, some of these compounds are impressive tongue-twisters. I can see why they go for so many acronyms. Breathe better, everyone, and thanks again, Professor Dave!

[@revenevan11]

Asthmatics, assemble!!!

[@hank_says_things]

Yeah (puff) just give me a sec (huff) gotta find my salbutamol

[@skawesomeone]

i was just prescribed albuterol lol. cool to see how it works

[@ghostagent3552]

You really should make a video on the Magneto-Turboencabulator this incoming April

[@sciencenerd7639]

thanks, this is an important topic

[@tgeliot]

When you have a "part N" video, can you please put a link to the earlier part(s) in the description? Right now, I'd like to find part 1 of this.

[@ProfessorDaveExplains]

Just check the pharmacology playlist linked in the description it’ll be right before this one.

[@user-qe5pz2dy9t]

Can I know sources you used to write for this video ? because I have a report about salbutamol and I need to added some sources when I write it😢

[@waelfadlallah8939]

Great explanation Prof Dave. I believe at 4:20 the shift mentioned is tilted towards more phosphatase activity rather than kinase activity. Correct me if i am wrong.

[@mikek4025]

Hi, I’m the script writer. That could certainly be the case. If you have seen some compelling data that backs that up thats totally fair. The point I’m trying to get across is these enzymes both contribute to transducing the efficacy of agonists at this receptor! Relative contributions are interesting to discuss.

[@lukas4235]

@@mikek4025
a phosphatase dephosphorylates, a kinase phosphorylates. hence the myosin light chain phosphatase cleaves the phosphate of the myosin light chain which causes smooth muscle relaxation

[@mikek4025]

@@lukas4235 yes

[@charlyzzz]

One thing I don't get is, when I have a long lasting asthma attack, the efficiency of salbutamol decreases with time. What is creating that short-term drug resistance?

[@mikek4025]

Hi, short term resistance is due to a beta2 adrenergic receptor internalisation from the cell surface membrane into intracellular compartments. This means the receptor is no longer present on the membrane to be activated by salbutamol, so the signalling mechanism can’t be transduced. Excellent question

[@Angular777]

I have a question: Do we actually know these reactions take place? Or is it assumed based on waste products and the fact that expected results take place? My chemistry is very rudimentary so sorry if this is a stupid question.

[@scptime1188]

We know how the cells work, and we know how the drugs work and what they are (we made them, duh), so i assume these effects are known to occur. We can use organic chemistry and cell biology to figure out what drugs will do, and make drugs that do what we want. So i assume the uncertainty is very low in terms of what reactions are taking place.

[@mikek4025]

There are some very intricate experiments that can demonstrate these reactions are happening. Short answer is yes we know these reactions happen this way from multiple different experiments, it’s not because of waste products, in most biological systems most proteins and indeed most chemical entities are constantly recycled

[@woodsfamily1100]

Can salbutamol relax the uterine smooth muscle, which contracts during menstrual periods causing pain?

[@DinorwicSongwriter]

Professor Dave, how do I message you directly?

[@siisjwj7647]

God bless you Professor David, very interesting video 👏

[@Vikram798]

Awesome 😎😎😎

[@davidtemple1189]

Hi, Dave!
Science Journalist Dave here.
I keep getting sucked into your old flat Earth videos.
CZcams just keeps pushing them at me.
I have one request. Replace "in actuality"with actually, please. Just a small thing that you may not do anymore anyway. Thanks for all your work.

[@bedheadbozo]

What happened to your channel, you deserve more views

[@ProfessorDaveExplains]

The academic tutorials never get tons of views on the day they are released, they accumulate views over time as students need them for their coursework.

[@yassinschool7017]

I'm sad this Chanel is almost dead :(

[@ProfessorDaveExplains]

November was the best month in the history of my channel.

[@yassinschool7017]

@@ProfessorDaveExplains I'm not being toxic man but really do love this Chanel even my science teacher use u as guide thanks man but wow ty

[@alobster9371]

Yooo I'm EARLY!

[@FelipeSouza-en7vb]

👏👏

[@WeSoap2]

massive resepct from me. you could make another anti-vaccine, political, or flat earth video and ger 40 trillion views, but you stay true to your content instead. respect from me.

[@terrypussypower]

A Salbutamol (Ventolin) inhaler has been my constant companion for almost 40 years! I never go anywhere without my house keys and my inhaler! And if I had to choose between my keys and my inhaler…I’d take the inhaler!

[@namajkatiufputkata]

cocaine is the best bronchodilator!

[@eremite2693]

Disgusting verbalism

[@ProfessorDaveExplains]

Um, what?