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- Wed Mar 01, 2006 1:04 am
Can someone read this and tell me if it says "bovine pituitary gland extract causes an observable increase in adrenal androgen secretion". I can't tell (I'm a programmer, not a medico).
[i]"Evidence for existence of cortical androgen-stimulating hormone
LN Parker and WD Odell
An animal model using dexamethosone-suppressed, castrated dogs was developed to test the hypothesis that a pituitary hormone other than ACTH modulates adrenal androgen (AA) secretion. Plasma samples were obtained every 15 min during infusions of saline, synthetic alpha 1-24 corticotropin, porcine 1-39 corticotropin (ACTH), or bovine pituitary gland extract (PE) in a wide range of doses. Androstenedione (A), dehydroepiandrosterone (DHA), and cortisol (F) were quantified by radioimmunoassay. When the ratio of AA levels was related to those of F, in order to correct for ACTH content in the PE, the slopes of the dose-response curves for corticotropin and PE were different at the 0.01 level. For A the dose-response slope for the PE was 0.18 +/- 0.5 SE, whereas that of ACTH was 0.02 +/- 0.01. For the DHA response the slopes were 0.17 +/- 0.04 for the PE and 0.04 +/- 0.03 for ACTH. Related studies showed no increase in AA levels in response to luteinizing hormone-releasing hormone, bovine growth hormone (GH), bovine prolactin, ovine thyroid-stimulating hormone (TSH), or synthetic aqueous arginine vasopressin (AVP). We conclude that a pituitary factor other than ACTH, prolactin, GH, luteinizing hormone, follicle-stimulating hormone, TSH, or AVP may be responsible for the observed increase in AA concentrations. [/i]"
| Dr. Shank
- Sat Mar 11, 2006 6:53 pm
Yes, it does.
Basically, all this abstract is trying to say is that there is something in an extract of the bovine pituitary gland that has a relatively greater effect to stimulate the adrenal glands to release adrogens (male-type sex hormones) as compared to cortisol (the main adrenal hormone), than either a synthetic ACTH or a porcine ACTH. Furthermore, this stimulation cannot be duplicated by a variety of known pituitary hormones (What it should have said is that this stimulation cannot be duplicated by a variety of known pituitary hormones by themselves, since the authors apparently did not test them in combination with the other ACTH preparations.). The authors conclude that there must be some unknown something else in the pituitary gland that stimulates the secretion of adrenal androgens (Considering the exhaustive work that has been done to isolate hormones from the pituitary gland, an even more plausible explanation is that there is something about the effects of bovine ACTH that is different from those of the other forms, but their explanation would certainly be a lot more exciting!). My guess is that they are already working feverishly to identify a previously unknown pituitary hormone that stimulates adrenal androgen secretion more than ACTH does. Since publishing this abstract is guaranteed to provoke a rush by big labs everywhere trying to duplicate their results and beat them to the possible identification of a new pituitary hormone, it would be a very safe bet that they are either (1) well along in their own search, (2) or that they are stuck and want to at least establish priority for this one small finding (and hopefully impress grant reviewers enough to get money to continue their search).
How does a computer programer get into such heavy basic science so far removed from his occupation?
By the way, in addition to being an endocrinlogist, I have a Ph.D. in Physiology and Biophysics for my own work on the hypothalamic-pituitary-thyroid-peripheral tissues axis.