[quote]anonym wrote:
To add to that original post, two other issues come to mind:
- Rat study. 'nuff said.
- The abstract states that “the separated peptides were tested for opioid-like activity by competitive binding to opioid receptor sites in rat brain tissue in the presence of tritium-labeled dihydromorphine.” Now, lifty is correct in saying that these peptides compete with tritium-labeled dihydromorphine for the available receptors; however, where he drifts from sound conclusions based on the information available from abstract to just parroting the authors’ conclusions without supporting evidence is the point at which he infers this somehow equates to activity. It should be noted that receptor affinity does not necessarily equal activity. There is a whole slew of drugs that act as receptor antagonists – many of them competitive, as studied in this paper – that, by virtue of their design, elicit minimal, if any, response after binding to the active site.
So, before we even take the authors at their word that the “activities” were comparable to the degree they specified, we would first need to check how they came to that conclusion. Simply showing that they bound to the receptors isn’t enough, though, I imagine there IS actual evidence of opioid activity floating about. Whether it’s significant is the big question.
And this is why I hate it when people flash abstracts without actually having read the study. No point even bringing it up if it can’t be adequately reviewed.[/quote]
I would expect anyone who throws around studies to at least come up with a similar analysis (based on the information in the abstract).
I will add a couple points though:
- The study was address links between schizophrenia and celiac disease. Because of the celiac disease component, the authors can assume partially digested peptides make it into the circulatory system.
- It is an in vitro study using rat brain homogenate. This does not, in any way, represent a physiological system to study opioid-like activity. This is the primary reason why this study does not mean jack.
BTW, Anonym, the authors do cite references addressing the opioid-like activity. However, they are, again, in vitro assays.