Posted by BillP on May 12, 2001 at 14:59:58:
In Reply to: Just a thought on Red Blood Cell rigidity posted by John Walker on May 12, 2001 at 10:52:21:
Wow, John! Thanks for the voluminous information. You absolutely dazzle me with the breadth of your knowledge. You are amazing. I have some questions for you though.
I'm not clear on why you posted this on a scuba diving forum rather than a cell biology discussion group. Why did you leave out the parts showing evidence that 1) spectrin is affected by diving, 2) increased partial pressures of nitrogen causes the effect on spectrin seen with diving, 3) elevated partial pressures of helium and oxygen do NOT have the same effect on spectrin as nitrogen, 4) helium NEGATES the effects that nitrogen has, and 5) this effect of nitrogen on spectrin (and therefore red blood cells) is clinically significant to recreational divers? Those points seem to be missing from your post.
I could come up with an equally long and dazzling (and confusing for the target audience?) explanation as to why very carefully controlled levels of sodium are vital to maintaining life functions, and then conclude that you should NEVER have ANY helium in your breathing mix. But then you'd expect me to come up with some evidence linking the two before you accepted my conclusion, wouldn't you?
But of course you didn't offer any evidence linking alterations in spectrin to diving, and you didn't draw any conclusions, did you? You just tossed out a lot of info to think about. I can't wait for you to get back from Akumal to fill in the blank spaces in your post!
Looking forward to it,
Bill
BTW, the studies that I'm aware of that look at the effect of pressure on spectrin in red cells used pressures of 1000-2000 ATA to see the effects. I certainly hope that you're not diving that deep! I look forward to your studies that show the effects I've mentioned above.