hey all,
I first always thought that an increase in ADH gives me the HGH-bloat. The following study comes to the conclusion that HGH doesnt increase ADH(1), but caused by an activation of the renin-angiotensin system.

exoGH increases somatostatin, the kidney got side specific receptors for somatostatin which may activate the renin-angiotensin system(2). This may cause the HGH bloat and can be inhibited by an ace-inhibitor.

1- "The antinatriuretic action of biosynthetic human growth hormone in man involves activation of the renin-angiotensin system.
Garvan Institute of Medical Research, St. Vincents Hospital, Darlinghurst, Sydney, Australia.

Previous studies using human pituitary extracts have not resolved whether the sodium retaining effects of human growth hormone (hGH) are mediated in part by increased aldosterone secretion. We have studied the effects of an authentic biosynthetic GH (bio-hGH) preparation on sodium metabolism and on the activity of the renin-angiotensin system. Six young men were administered this preparation at 0.2 U/kg/d subcutaneously for five consecutive days. Twenty-four-hour urine collections were obtained for measurement of sodium excretion and osmolality and blood collected for quantitating changes in sodium, osmolality, plasma renin activity (PRA), aldosterone, and arginine vasopressin (AVP) concentrations. Bio-hGH administration resulted in a fall in 24-hour urinary sodium excretion (197 +/- 38 to 42 +/- 20 mmol, mean +/- SD, P less than .005), a reduction in urine volume (1,652 +/- 182 to 848 +/- 348 mL, P less than .05) but not osmolality. PRA increased significantly from 1,118 +/- 73 to 3,608 +/- 1,841 fmol angiotensin 1 L/s (P less than .005), which was associated with a sevenfold increase in plasma aldosterone concentration (52 +/- 12 to 402 +/- 99 pg/mL, P less than .001). Plasma osmolality and AVP concentrations did not change significantly. The results show that Bio-GH-induced retention of sodium involves the activation of the renin-angiotensin system. This mechanism may explain in part the occurrence of plasma volume expansion and hypertension in acr*****ly and suggests a risk of fluid retention and possibly hypertension in subjects receiving supraphysiological doses of bio-hGH for treatment of short stature.
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