I'm leaning away from the aldosterone theory now-- it is still valid, of course, but I have a feeling (based upon the evidence) that most non-responders and negative-responders are that way because of something else (see earlier posts for current theories).
Why are you leaning away from it? We still have all of these theories floating up in the air. Why are you beginning to favor these other theories over this one? I'm just curious what it is that's changing your mind, here. for one, every other aspect of piracetam's pharmacology aside from its role with aldosterone seem less definitive - aldosterone is the one thing that it appears piracetam needs to work. Up until this point, I was under the impression the "aldosterone hypothesis" was created by noting and relating two distant facts: that many of us seem to have pupil fluctuations indicative of aldosterone deficiency, and also that piracetam is ineffective when certain adrenal hormones are not present, which would lead to the idea that aldosterone in specific may be what's altering and leading to a reduction in piracetam's effectiveness/negative symptoms, if not suggesting a deficiency further up in the hormone pathway. I only came across this study just now, which specifically isolates aldosterone in piracteam's function(I don't think it's been posted, apologies if it has):
Aldosterone receptors are involved in the mediation of the memory-enhancing effects of piracetam.
Mondadori C, Häusler A.
Pharmaceutical Research Department, CIBA-GEIGY Limited, Basel, Switzerland.
The blockade of the memory-enhancing effects of piracetam resulting from adrenalectomy can be abolished by substitution with either corticosterone or aldosterone. However, corticosterone substitution does not reinstate these effects if the aldosterone receptors are blocked by the aldosterone antagonist epoxymexrenon.
Conclusion = memory enhancing effects of piracetam are dependent on aldosterone. Other mental markers aren't tested here, so we can't say how much of a global role aldosterone plays. Given the multiple systems at hand (acetylcholine, glutamate), it would seem overly simplistic to believe it's merely aldosterone which the whole boat is floating on.
I'd be curious to hear if any others have noticed symptoms of electrolyte imbalance while on, or after coming off piracetam. I notice symptoms such as apparent dehydration minus the expected thirst, and very dark urine, which i rarely have otherwise. These symptoms are most marked directly after stopping the piracetam, though when I'm stopping it, I'm also usually stopping it for a reason, if that says something. I'll also leak urine after taking a piss in a way which is problematic and which doesn't happen normally. It almost definitely only happens while I'm on the piracetam. maybe the latter could have something more to do with acetylcholine?
The hormone aldosterone regulates kidney removal of sodium and potassium. Lack of aldosterone can result in hyperkalemia with an increase in total body potassium.
on hyperkalemia:
Increased extracellular potassium levels result in depolarization of the membrane potentials of cells. This depolarization opens some voltage-gated sodium channels, but not enough to generate an action potential. After a short while, the open sodium channels inactivate and become refractory, increasing the threshold to generate an action potential. This leads to the impairment of neuromuscular, cardiac, and gastrointestinal organ systems. Of most concern is the impairment of cardiac conduction which can result in ventricular fibrillation or asystole.
This sounds just like the sort of general malaise piracetam seems to cause after a while. It sounds like it can also cause dark urine and dehydration. I'm not saying this is IT, but it does seem like it needs further investigation, IMO.
If anyone really wanted to play guinea pig for the pack, Fludrocortisone, a synthetic aldosterone agonist, is widely available very cheaply over the internet. Extreme caution would be necessary, with a specialist's supervision, regular blood pressure testing, and aldosterone/electrolyte labwork being strongly advised. I'm not sure where I stand on the whole eye fluctuation matter, but if it really was a reliable indicator it would be very handy when trying to gauge Fludrocortisone dose. That and blood pressure. It'd be prudent to test blood pressure at baseline levels, followed by a low dose, perhaps a 1/4 dose of 0.025 mg. Doses used to treat Addison's are within the 0.1 - 0.2 mg range, whether for cat, dog, human, or god. The same dose might be tested every two days. Supposing a week passes without acquiring something like necrotizing angiitis, the dose might then be raised to 0.25 mg daily, followed by careful monitoring of blood pressure, which appears to be the first thing which can go wrong with this medication. If there is any indication of side-effect, it should be stopped immediately.
I'm sure you guys will love the favorable side effect profile:
Most adverse reactions are caused by the drug's mineralocorticoid activity (retention of sodium and water) and include hypertension, edema, cardiac enlargement, congestive heart failure, potassium loss, and hypokalemic alkalosis.
When fludrocortisone is used in the small dosages recommended, the glucocorticoid side effects often seen with cortisone and its derivatives are not usually a problem; however the following untoward effects should be kept in mind, particularly when fludrocortisone is used over a prolonged period of time or in conjunction with cortisone or a similar glucocorticoid.
Musculoskeletal-muscle weakness, steroid myopathy, loss of muscle mass, osteoporosis, vertebral compression fractures, aseptic necrosis of femoral and humeral heads, pathologic fracture of long bones, and spontaneous fractures.
Gastrointestinal-peptic ulcer with possible perforation and hemorrhage, pancreatitis, abdominal distention, and ulcerative esophagitis.
Dermatologic-impaired wound healing, thin fragile skin, bruising, petechiae and ecchymoses, facial erythema, increased sweating, subcutaneous fat atrophy, purpura, striae, hyperpigmentation of the skin and nails, hirsutism, acneiform eruptions, and hives; reactions to skin tests may be suppressed.
Neurological-convulsions, increased intracranial pressure with papilledema (pseudotumor cerebri) usually after treatment, vertigo, headache, and severe mental disturbances.
Endocrine-menstrual irregularities; development of the cushingoid state; suppression of growth in children; secondary adrenocortical and pituitary unresponsiveness, particularly in times of stress (e.g., trauma, surgery, or illness); decreased carbohydrate tolerance; manifestations of latent diabetes mellitus; and increased requirements for insulin or oral hypoglycemic agents in diabetics.
Ophthalmic-posterior subcapsular cataracts, increased intraocular pressure, glaucoma, and exophthalmos.
Metabolic-hyperglycemia, glycosuria, and negative nitrogen balance due to protein catabolism.
Allergic Reactions-allergic skin rash, maculopapular rash, and urticaria.
Other adverse reactions that may occur following the administration of a corticosteroid are necrotizing angiitis, thrombophlebitis, aggravation or masking of infections, insomnia, syncopal episodes, and anaphylactoid reactions.
anyway, I don't think anyone should try this, it seemed more viable until I looked into the side effects in more depth. I'll leave it here for information.
Thankfully I think i may have found a better option.
Lets take a look at corticosterone:
Corticosterone itself doesn't seem to do much, mostly being an intermediate between progesterone and aldosterone while possessing minor glucocorticoid and mineralocorticoid activity. One supplement which has been shown to increase corticosterone levels, and hence aldosterone levels, is carnosine:
Effect of central administration of carnosine and its constituents on behaviors in chicks.
Tomonaga S, Tachibana T, Takagi T, Saito ES, Zhang R, Denbow DM, Furuse M.
Laboratory of Advanced Animal and Marine Bioresources, Graduate School of Bioresource and Bioenvironmental Science, Kyushu University, Fukuoka 812-8581, Japan.
Even though their contents in the brain are high, the function of brain carnosine and its constituents has not been clarified. Both carnosine and anserine inhibited food intake in a dose dependent fashion when injected intracerebroventricularly. The constituents of carnosine, beta-alanine (beta-Ala) and l-histidine (His), also inhibited food intake, but their effects were weaker than carnosine itself. Co-administration with beta-Ala and His inhibited food intake similar to carnosine, but also altered other behaviors. Injection of carnosine induced hyperactivity and increased plasma corticosterone level, whereas beta-Ala plus His induced hypoactivity manifested as sleep-like behavior. This later effect seemed to be derived from beta-Ala, not His. These results suggest that central carnosine may act in the brain of chicks to regulate brain function and/or behavior in a manner different from its constituents.
aside from increasing corticosterone levels, it seems to be a useful and safe supplement in itself:
http://en.wikipedia.org/wiki/Carnosine
http://en.wikipedia....cetyl-carnosine
I'm not sure which would be preferred, but I might guess the latter, unless it is one of the carnosine metabolites which produces the effects (the acetyl version producing less of these metabolites, sustaining its form, and thus being considered better by some people. I'm not sure how to interpret the reports of carnosine causing hyperactivity in humans. I feel this may either be offset by the piracetam, or that this just might seem to go along with what piracetam does to begin with. When piracetam is really working, it wouldn't seem to be a stretch to label the feeling as being somewhat hyperactive, IMO. Not saying corticosterone/aldosterone are involved in this.
we then have magnesium:
Effect of Magnesium Deficiency on Corticosterone in Rats
C. L. RICHER, R. VEILLEUX and P. BOIS
Départmént d’Anatomie, Université de Montréal Montréal Québec, Canada
Abstract
Corticosterone in adrenal glands and plasma was measured by a fluorometric method in rats fed a magnesium-deficient diet, in 2 control groups receiving the same diet supplemented with different quantities of magnesium, and finally in animals fed regular laboratory chow. Eosinophils in blood were also counted. Corticosterone in the magnesium-deficient group showed a statistically significant decrease that was already apparent after 15 hr on the diet and persisted throughout the 20 days of the experiment. The control diet containing the smaller supplement of magnesium was sufficient to maintain body weight gain and to prevent erythema and eosinophilia but corticosterone levels were decreased also in this group. The animals receiving the larger magnesium supplement showed corticosterone levels similar to those of the rats fed laboratory chow. These findings suggest that the reduction of corticosterone is a sensitive index of suboptimal magnesium intake. (Endocrinology 82: 954, 1968)
This seems interestng, considering magnesium's interaction with NMDA/glutamate. It is possible excess ca++ from increased glutamatergic activity is suppressing corticosterone via magnesium reduction? Would someone more knowledgeable than I like to try to dissect the possible relationship here? Whether or not it's a good adjunct to piracetam is another question, considering its NMDA antagonism. This could help or hurt, I'm not sure.
then we've got this:
Changes in Rat Serum Corticosterone After Treatment with Metabotropic Glutamate Receptor Agonists or Antagonists
M. P. Johnson , G. Kelly and M. Chamberlain
Neuroscience Research, Lilly Research Laboratories, Eli Lilly & Company, Lilly Corporate Center, Indianapolis, IN, USA.
Correspondence to: Michael P. Johnson, Neuroscience Research DC0510, Lilly Corporate Center, Indianapolis, IN 46285, USA (e-mail: johnson_michael_p@lilly.com).
Copyright British Neuroendocrine Group
KEYWORDS
mGlu • DHPG • LY393675 • corticosterone • glutamate.
ABSTRACT
Abstract
From previous work, it appears that glutamate can activate the hypothalamic-pituitary-adrenocortical (HPA) axis by an interaction at either ionotopic or metabotropic (G-protein coupled) receptors. For example, (1S,3R)-1-aminocyclopentane-1,3-dicarboxylate (ACPD), a metabotropic glutamate (mGlu) receptor agonist, has been shown to increase the levels of serum corticosterone in rats. The present study was undertaken to further characterize which of the mGlu receptors are substantially involved in control of the HPA axis. The group I mGlu receptor agonists, 3,5-dihydroxyphenylglycine (DHPG), 1S,3R-ACPD, and 2-chloro-5-hydroxyphenylglycine (CHPG) but not the inactive isomer 1R,3S-ACPD were found to dose-dependently increase serum corticosterone 1 h after intracerebroventricular (i.c.v.) injection in male rats. The relative potency, DHPG (EC50 = 520 nmol) > 1S,3R-ACPD (1.4 µmol) = CHPG (2.7 µmol) ≫ 1R,3S-ACPD (≫ 3 µmol) is consistent with activation of group I (mGlu1/5) receptors. The effects of DHPG were long lasting with substantial elevations in corticosterone remaining for at least 3 h. In a similar manner, the group III mGlu receptor agonists, L-AP4 (4-phosphono-2-aminobutyric acid) and L-SOP (serine-O-phosphate), were found to increase serum corticosterone levels at 1 h. In contrast, the mGlu group II selective agonists LY354740 (10 mg/kg, i.p.) and subtype-selective doses of the group II antagonist LY341495 (1 mg/kg, i.p.) did not significantly elevate serum corticosterone. Given the group I agonists results, it was surprising to find that group I selective and mGlu1 selective antagonists given alone also increased serum corticosterone. As with the agonists, the rise in serum corticosterone with LY393675 (an mGlu1/5 antagonist, EC50 = 20 nmol, i.c.v.) and LY367385 (an mGlu1 antagonist, 325 nmol, i.c.v.) were dose-dependent and consistent with their relative affinity for the group I mGlu receptors. The selective mGlu5 antagonist MPEP [2-methyl-6-(phenylethylnyl)pyridine] increased serum cortocosterone but only at high doses (> 30 mg/kg, i.p.). A model involving the high glutamatergic tone on GABAergic interneurons in the paraventricular nucleus of the hypothalamus is discussed as a possible explanation for these results.
Corticosterone has AMPA activity:
Corticosterone Slowly Enhances Miniature Excitatory Postsynaptic Current Amplitude in Mice CA1 Hippocampal Cells
Henk Karst and Marian Joëls
Center for Neuroscience, Swammerdam Institute for Life Sciences, University of Amsterdam, Amsterdam, The Netherlands
Submitted 10 February 2005; accepted in final form 13 July 2005
Corticosteroid hormones are released in high amounts after stress and bind to intracellular receptors in the brain, which in activated form function as transcription factors. We here tested the effect of a high dose of corticosterone on AMPA-receptor–mediated transmission in the CA1 hippocampal area, which is enriched in corticosteroid receptors. To focus on slow gene-mediated effects of the hormone, excitatory postsynaptic currents were measured at least 1 h after a brief application of 100 nM corticosterone to slices from adrenally intact adult mice. The amplitude but not frequency of miniature postsynaptic excitatory currents was found to be significantly enhanced. These effects were mimicked by 100 nM RU 28362, a selective agonist for intracellular glucocorticoid receptors. Evoked AMPA responses at the single cell were significantly enhanced when measured 2–4 h after application of 100 nM corticosterone, but not at earlier moments nor with a longer delay. In summary, the present results show that activation of hippocampal glucocorticoid receptors induces a slow enhancement of AMPA-receptor–mediated responses, at the single-cell level.
In conclusion, I'd predict that carnosine or acetyl-carnosine would be a safe/effective means to increase corticosterone, and hence aldosterone. This would lead to either a reduction or elimination of any aldosterone deficiency, and could potentially have very profound effects when combined with piracetam. Unlike some of the other hormones, Corticosterone is far enough down the pathway to not metabolize into anything other than aldosterone and it's intermediate, preventing risk for hormone imbalance.
I pulled an all nighter last night and I still haven't slept, so excuse any typos, etc.
Edited by brain, 03 February 2010 - 01:50 AM.