[quote]Tim Ziegenfuss wrote:
Yes, we (Biotest) are looking into aspartic acid…
Also, 40% may not seem like a big increase, but when timed properly it may help upregulate androgen receptors. For example:
J Steroid Biochem Mol Biol. 2009 Apr;114(3-5):195-9. Epub 2009 Feb 21.
Elevated endogenous testosterone concentrations potentiate muscle androgen receptor responses to resistance exercise.
Spiering BA, Kraemer WJ, Vingren JL, Ratamess NA, Anderson JM, Armstrong LE, Nindl BC, Volek JS, H�¤kkinen K, Maresh CM.
Department of Kinesiology, University of Connecticut, 2095 Hillside Road, Storrs, CT 06269, USA.
Abstract
The purpose of this study was to determine the influence of endogenous circulating testosterone (T) on muscle androgen receptor (AR) responses to acute resistance exercise (RE). Six healthy men (26+/-4 years; 176+/-5 cm; 75.8+/-11.4 kg) performed a knee extension exercise protocol on two occasions separated by 1-3 weeks. Rest preceded one trial (i.e., control [CON] trial) and a high-volume upper-body RE protocol designed to increase circulating T preceded the other trial (i.e., high T [HT] trial). Serial blood samples were obtained throughout each trial to determine circulating T concentrations. Biopsies of the vastus lateralis were obtained pre-RE (REST), 10-min post-RE (+10), and 180-min post-RE (+180) to determine muscle AR content. Circulating T concentrations remained stable during CON. Alternately, HT significantly (p< or =0.05) increased T concentrations above resting values (+16%). Testosterone area-under-the-time curve during HT exceeded CON by 14%. AR content remained stable from REST to +10 in both trials. Compared to the corresponding +10 value, muscle AR content at +180 tended to decrease during CON (-33%; p=0.10) but remained stable during HT (+40%; p=0.17). Muscle AR content at +180 during the HT trial exceeded the corresponding CON value. In conclusion, acute elevations in circulating T potentiated muscle AR content following RE.
Over time, I would expect an effect like that to improve training adaptations.
TZ[/quote]
Dr. Z - I’m just following up to see the status of Biotest’s testing.
I’m curious why you quoted the research on the acute effect of training on AR (2nd study). Are you guys gonna test or have you tested the acute response of this stuff?
The (1st) study you quoted about DAA showed that “the ingested D-Asp also still remains accumulated significantly in the testes 3 days after D-Asp suspension of treatment… we deduce that the persistent increase of testosterone in rat blood is due to the accumulation of D-Asp that persists leading to stimulated testosterone production.” To me that does not show the significance of the acute reponse. Is there something that leads you to believe that the acute response is significant? The methods state that blood was sampled “before treatment, after 6 days of treatment, after 12 days of treatment, and 3 days after suspension of the treatment.” I don’t see a basis to determine the significance of the acute response. Maybe you theorize otherwise. It kinda seems like creatine though, where you have to build up a certain amount.
The study does not answer any questions about how long it would be necessary to cycle off, since test levels remained high 3 days after testing (since the DAA in testes remained there for at least that long, and continued to stimulate LH and test).
Do you have any new recommendations? A penny for your thoughts. Thanks.