I'm not sure what the benefit of injecting GABA would be, since it not supposed to cross the blood-brain barrier and it's actions are on neurons in the brain. It would be detectable in blood if injected, but not if you could give a precursor that increased GABA production in the brain. Anyone know how it functions in the peripheral nervous system vs the CNS?
When injected it produces marked sedation. Perhaps you read that it's inert when administered orally?
GABA is the brain's major inhibitory transmitter (naturally). There are drugs, which we refer to as GABA-mimetic in medicine, which do exactly like the name says, mimic the actions of natural GABA. These include drugs classified as Benzodiazepines, such as Valium, Ativan, and Versed. When given in appropriate doses to people they are used for sedation or to decrease anxiety. Hope this gives you an idea of what it will do it we give GABA to horses. As far as oral doses passing the BBB, it is my understanding that it depends on the pKa of the drug, so if a drug company can make a compound that is un-ionized, then it will be absorbed in the gut. Hope that helps.
If I'm not mistaken, GABA is also an ingredient in the oral product Pro Focus. Does anyone know if this is the case? If so, this and any other oral products containing GABA are now similarly banned by the USEF, in theory, though the same situation of not being able to test for it (yet) would apply. Just wondering. Also wondering if anyone with pharmaceutical knowledge can address the question of sedation of horses with this injectable form (Carolina Gold) vs. an oral product like Pro Focus.
The link above is a study that was published in 2010. Patients were given Oral GABA or a placebo after cardiac surgery. The patients who got the oral GABA were in significantly less pain and needed less morphine.
This study was done in 2011 and looked at the brain waves of humans who took oral GABA versus placebo and there was significantly decreased brain waves in people who took oral GABA.
There does not seem to be any good studies that show exactly how much GABA crosses the blood brain barrier, and it is mentioned that GABA is a large molecule so it has difficulty crossing, but there is recent research that shows it does have effects.
I suggest that you do not give anything that has GABA as an ingredient, whether it is oral or IV… especially when they figure out how to test for it.
There is no strong evidence supporting claims that GABA reaches the brain when given orally, but it is absolutely known to have sedative properties when administered by injection. A very simplified version of how GABA works in the brain:
GABA is an inhibitory neurotransmitter, meaning that it disrupts nerve impulses. This directly produces a calming effect. On a very basic level it can be seen as the body's natural chill pill, or organic valium, if you will.
Someone mentioned glutamate in this or the other thread as being related to GABA. Well, it is, and it's not. GABA is synthesized from glutamate, but they have opposite effects in the CNS. Glutamate is an excitatory neurotransmitter, kind of like our own natural cuppa' Joe.
So, lots of GABA in our neurons, along with hungry GABA receptors at the synapses results in calming in 2 ways - the GABA's direct calming influence and the blocking of glutamate's firing signals.
Neither GABA nor glutamate has been proven to do much of anything when administered orally and it's a stretch (to say the least) to assume that increased GI absorption of either compound will result in CNS changes. IOW, just as it's unlikely for fed GABA to sedate a horse, it's also highly unlikely that feeding glutamate will step up GABA production in the CNS.
We're discussing GABA as if it's the latest and greatest (okay, maybe not so great) new thing. But it's not. We've been mokeying around with GABA in our horses' brains for decades. Magnesium binds to GABA receptors and increases GABA's effects, Taurine protects against glutamate over stimulation (think of how you feel when you've had too much coffee - that's due in part to glutamate over stimulation and GABA deficiency), Serotonin, another neurotransmitter enhances GABA effects and tryptophan is a serotonin precursor. Vitamin B6 is a coenzyme involved in GABA synthesis and theanine, which is in all the new green tea supps., increases glutamate transport and GABA levels. Valerian increases the effect of GABA on its receptors and the entire benzodiazepine family of drugs acts on GABA receptors in one way or another, enhancing the inhibitory effects of GABA on neurons.
I'm sure it's just a matter of time until someone finds another way to influence neurotransmitter activities in the interest of "enhancing a horse's calm".
Waiting for the USEF to issue the penalties to those whose horses have tested positive for GABA....any day now. The August hearings should have taken place. The sooner the announcements are made public the better for the sport. Maybe an end to the sleepy hunters and a return to real horse training. There are lots of rumors about who, what, and when but an official ruling will go a long way to restoring some faith in the USEF for cleaning up the sport.
Last edited by violethorse; Aug. 27, 2012 at 05:46 PM.
An "inhibitory neurotransmitter" does what? Calm a horse? I would assume that is the reason it is banned.
The USEF's position on stuff like that is:  you can't use any calming agent, if it works and/or masks something; and  you can't use any agent, EVEN IF IT DOESN'T DO A THING, if you think it does something.
It was banned because it violated the intent of the rules and adverse effects have been reported in animals undergoing testing of these products. It was not banned because it actually does anything, because ingesting GABA pretty much gets you a mess of semi-digested amino acids and bits of polysaccharide. Injecting it is another story, and bloody frightening, if you ask me.
The lengths people will go to to avoid choosing suitable horses and training them appropriately.
But maybe if horses that showed some animation, liveliness, and initiative were pinned higher, the need for doped-up animals would disappear. That intervention would cost NOTHING!