Re: frog heart beats - 1920s?

[Ruth Sponsler <jk5554@yahoo.com>]

What is the cite for the frog dissection mentioned? 

(even if it's a 1-paragraph note in a 1920s journal). 

What was the isotope?  



Was there possible contamination with Ca++ in a

concentration that could induce beating after the

heart of the frog had stopped beating?  The reason I

mention this is that if RaCl2 were used back in the

1920s, and had been separated out using Mme. Curie's

method, there was likely some CaCl2 present as well

(in larger mole quantity than the Ra).  



As it happens, Ca++ acts to regulate muscle

contraction with actin, myosin, and ATP (the energy

currency of cells).  From a web site about frog heart

beats:



"Historical experiments: In 1883, Ringer observed that

contraction of isolated frog heart ceases when CaCl2

was omitted from the bathing solution. This was

reversible."  (Ringer, of Ringer's soln.)



Trying this (avoiding having any Ca++ present and

perhaps using an isotope of an element that is not

physiologically active) sounds like something for a

'non-squeamish' science fair participant??





~Ruth 2



(the froggy heartbeat link below is probably not

interesting to most, but it's where the Ringer comment

came from)

http://www.uic.edu/classes/phyb/phyb516/regulationmusclecontru3.htm





 

> Ionizing radiation is essential for biology to

> function. In the early 2oth

> Century experiments such as dissecting a frog to

> provide access to the

> heart, and after death (heart stopping after brain

> death), a drop of water

> with radioactivity restarted the heart.



> Regards, Jim Muckerheide

> ========================





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