This further supports the fact that MGF could be the great mediator for increasing the length of an IGF-1 cycle. This study shows a huge increase in MGF from hGH administration and even though IGF-1 levels due increase, it increased much less than that of MGF. It has been said that LR3 IGF-1 administration can cause decreased hGH levels and therefore less MGF levels. Could be "one" of the reasons for gains tapering off as i have mentioned before.
The effect of recombinant human growth hormone and resistance training on IGF-I mRNA expression in the muscles of elderly men
M. Hameed1, K. H. W. Lange3, J. L. Andersen4, P. Schjerling4, M. Kjaer3, S. D. R. Harridge2 and G. Goldspink1
1 Department of Surgery2 Department of Physiology, Royal Free and University College Medical School, Rowland Hill Street, London NW3 2PF, UK,3 Sports Medicine Research Unit, Bispebjerg Hospital, Copenhagen Muscle Research Centre, Copenhagen, Denmark4 Department of Molecular Muscle Biology, Copenhagen Muscle Research Centre, Copenhagen, Denmark
The expression of two isoforms of insulin-like growth factor-I (IGF-I): mechano growth factor (MGF) and IGF-IEa were studied in muscle in response to growth hormone (GH) administration with and without resistance training in healthy elderly men. A third isoform, IGF-IEb was also investigated in response to resistance training only. The subjects (age 74 ± 1 years, mean ±S.E.M) were assigned to either resistance training with placebo, resistance training combined with GH administration or GH administration alone. Real-time quantitative RT-PCR was used to determine mRNA levels in biopsies from the vastus lateralis muscle at baseline, after 5 and 12 weeks in the three groups. GH administration did not change MGF mRNA at 5 weeks, but significantly increased IGF-IEa mRNA (237%). After 12 weeks, MGF mRNA was significantly increased (80%) compared to baseline. Five weeks of resistance training significantly increased the mRNA expression of MGF (163%), IGF-IEa (68%) and IGF-IEb (75%). No further changes were observed after 12 weeks. However, after 5 weeks of training combined with GH treatment, MGF mRNA increased significantly (456%) and IGF-IEa mRNA by (167%). No further significant changes were noted at 12 weeks. The data suggest that when mechanical loading in the form of resistance training is combined with GH, MGF mRNA levels are enhanced. This may reflect an overall up-regulation of transcription of the IGF-I gene prior to splicing.
The effect of recombinant human growth hormone and resistance training on IGF-I mRNA expression in the muscles of elderly men
M. Hameed1, K. H. W. Lange3, J. L. Andersen4, P. Schjerling4, M. Kjaer3, S. D. R. Harridge2 and G. Goldspink1
1 Department of Surgery2 Department of Physiology, Royal Free and University College Medical School, Rowland Hill Street, London NW3 2PF, UK,3 Sports Medicine Research Unit, Bispebjerg Hospital, Copenhagen Muscle Research Centre, Copenhagen, Denmark4 Department of Molecular Muscle Biology, Copenhagen Muscle Research Centre, Copenhagen, Denmark
The expression of two isoforms of insulin-like growth factor-I (IGF-I): mechano growth factor (MGF) and IGF-IEa were studied in muscle in response to growth hormone (GH) administration with and without resistance training in healthy elderly men. A third isoform, IGF-IEb was also investigated in response to resistance training only. The subjects (age 74 ± 1 years, mean ±S.E.M) were assigned to either resistance training with placebo, resistance training combined with GH administration or GH administration alone. Real-time quantitative RT-PCR was used to determine mRNA levels in biopsies from the vastus lateralis muscle at baseline, after 5 and 12 weeks in the three groups. GH administration did not change MGF mRNA at 5 weeks, but significantly increased IGF-IEa mRNA (237%). After 12 weeks, MGF mRNA was significantly increased (80%) compared to baseline. Five weeks of resistance training significantly increased the mRNA expression of MGF (163%), IGF-IEa (68%) and IGF-IEb (75%). No further changes were observed after 12 weeks. However, after 5 weeks of training combined with GH treatment, MGF mRNA increased significantly (456%) and IGF-IEa mRNA by (167%). No further significant changes were noted at 12 weeks. The data suggest that when mechanical loading in the form of resistance training is combined with GH, MGF mRNA levels are enhanced. This may reflect an overall up-regulation of transcription of the IGF-I gene prior to splicing.