To: tonyt who wrote (15082 ) 2/15/1998 2:04:00 AM From: Torben Noerup Nielsen Read Replies (5) | Respond to of 32384
>"It always amazes me that people can get excited about rat data since >it is not really predictive of how a drug will work in humans," said >analyst Charles Engelberg. I have difficulty taking anyone who makes such blanket statements seriously. It really needs to be qualified quite strongly before it makes sense. Consider what happends if you make a rat breathe cyanide gas. I can promise you that it will die even with very low concentrations. So will a human (Tony, if you do not believe me, you might try it... :-)). The reason for this is that evolution tends to preserve fundamental processes - such as breathing - as much as it can. And I believe that when it comes to breathing, all mammals are pretty close (let the real biologists correct me if I am wrong; there might well be exceptions). This is true for a lot of processes at a cellular level. As far as I am aware, the basic energy transport systems are just about identical in all mammals and so are a lot of other things. I may be wrong, but I believe that differences in basic cellular processes are more the exception than the rule when it comes to mammals and it is such processes we are talking about. Or isn't it? No, I am not trying to say that rat results will always translate directly to humans, but I strongly believe that rat results will at the very least provide a strong starting point for rational drug design; i.e., tailoring a drug that is known to work in very well in rats to make it work very well in humans. Note that it is my understanding gleaned from one of Henry's posts that the rat tumors exhibited the same mutation in their ras gene as that found in the human equivalent. Henry, didn't you quote that from an article? As a side note, it never cease to amaze me how hard a time we have finding drugs that will consistently wipe out fairly simple prokaryotes without harming eukaryotic cells. Yes, I know there are rational answers to this, but I am still amazed. Cheers, Torben