jimbosmith316

MuscleChemistry



The following study focused on pulsatile versus continuous GH. The I.V. route was used and as you can clearly see in my comparison charts because it mimics a pulse clearly better then subcutaneous or intramusclular.

At the time of the study GHRPs/GHRH were not so much studied. So do not take this study to demonstrate that intravenous is best rather focus on pulsation versus continuous.

The following chart comes from a post here: ]GH response curve for small GH doses .27iu, .8iu & 1.6iu[/URL]
[FONT=&quot]At the time GH 1mg = 2.7iu

1iu = 370mcg

So the doses used for this chart in a 100kg man approximate:
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[FONT=&quot]6mcg/kg = 1.6iu
3mcg/kg = .8iu
1mcg/kg = .27iu

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Intravenous growth hormone: growth responses to patterned infusions in hypophysectomized rats, R. G. Clark, J.-O. Jansson, O. Isaksson and I. C. A. F. Robinson,Journal of Endocrinology (1985) 104, 53-61

Young hypophysectomized rats were maintained with chronic indwelling i.v. cannulae attached via swivels to a multichannel pumping system programmed to deliver GH in a continuous or pulsatile pattern for several days.

Continuous i.v. infusions of human GH for 5 days produced dose-dependent increases in body weight and tail length, without increasing food intake. A comparison of GH infusions by the s.c. or i.v. route showed that the direct i.v. route was threefold more effective.

Pulsatile i.v. infusions of human or bovine GH at two doses (12 or 36 mu./day, eight pulses/day, 5-min duration, every 3 h) produced greater increases in body weight than continuous i.v. infusions of GH at the same daily dose.

Continuous infusions of bovine GH produced a lower growth rate in the second of two consecutive 5-day treatment periods, whereas the responses to pulsatile GH did not diminish with time.

Both body weight gain and long-bone growth were affected by the frequency of GH pulses; nine pulses per day were more effective than three pulses per day which in turn produced larger growth responses than one pulse per day.

Keeping GH pulse frequency constant and varying pulse duration (4, 16 or 64 min) did not affect growth rates.

In conclusion, long-term pulsatile i.v. infusions of GH mimic the endogenous secretory pattern, and are most effective when given at the physiologically appropriate pulse frequency.


So from this study you can see continuous infusion creates desensitization greatly while pulsation does not.

The frequency of pulses were the most important factor in increasing growth. 9 better then 3 better then 1 better then continuous. The duration of the pulse didn't matter so long as it was still viewed as a single pulse by the body.

Anyway, although not a human study it is never-the-less one of the early ones among many that are instructive for bodybuilders.
 
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