Flashcards
Beta-Adrenoreceptors 2 *****
Flashcards do conjunto (18)
- 1—they act on the same tissue --> use same signalling pathway but different effects
- 2how does prostaglandin E1 differ from endocrine hormones?because rather than being secreted from a single gland, they are produced in multiple places in the body
- 3what did Ted Rall point out?unsatisfactory picture of PKA catalytic subunits phosphorylating many non-specific targets throughout the cell
- 4what can be determined about NA signalling based on these principles?there must be something regulating the PKA/cAMP signalling
- 5what does Forskolin do?adenylyl cyclase activator --> bypasses B-receptor
- 6what is the 'off' switch for cAMP?PDE = phosphodiesterases
^metabolise cAMP - 7—black dots/line represent peak voltage gated Ca2+ current.
a= current level
b= in the presence of prostaglandin E1 (no effect on Ca2+ current)
c= in the presence of isoprenaline (B agonist) - produces marked increase in Ca2+
- 8—drugs/solution can be diffused to different parts of the cell (s1,s2)
a = true control
b= the control current without Ca2+ extracellular
c= 1uM ISOPRENALINE delivered to one half of the cell primarily --> theoretically cAMP should be able to diffuse all throughout the cell resulting in a maximal response
d= maximal response seen when ISOPRENALINE applied to both sides of the cell simultaneously
- 9what can we conclude from pervious slide?prostaglandin E1 has no effect on Ca2+ current, but ISOPRENALINE (an adrenaline analogue/ agonist) does despite both acting vis cAMP
- 10what was the conclusion by Fischmeister in his experiment on frog vascular cells?ISO added to one half of the cell only produced half the possible maximal response - B-adrenoreceptor activation on one side of the cell isn't resulting in full activation of target proteins despite cAMP being freely diffusible
SYSTEM IS BEING REGULATED - 11—second addition from other side of the cell makes no difference. if you bypass B-adrenoreceptors FSK addition to a single half of the cell causes a maximal response - cell isn't regulating FSK
- 12give an example of a PDE inhibitor?milrinone
- 13give an example of a non-selective PDE inhibitorIBMX
isomethylxanthine - 14what effectndo PDE inhibitors have?reduce cAMP metabolism --> ^ [cAMP] --> increase in Ca2+ current
- 15—x
- 16name a B1 specific antagonistbisoprolol
- 17name a B2 selective antagonistzinterol
- 18****** FINISH
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- 2nd Year Developmental and Celluar Physiology of the Specialised Cell FlashCards sobre Beta-Adrenoreceptors 2 *****, criado por William Chapman em 23-05-2016.
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- William Chapman
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