Time period in which exogenous GH shuts down endogenous release->nandi,others PLEASE

Posted by: jboldman

show us.

jb

sure

to begin

Igf can be increased 3-5 fold.

J Clin Endocrinol Metab. 2003 Nov;88(11):5221-6.

High dose growth hormone exerts an anabolic effect at rest and during exercise in endurance-trained athletes.

Healy ML, Gibney J, Russell-Jones DL, Pentecost C, Croos P, S�nksen PH, Umpleby AM.

------------------ Baseline --------- 1Wk-----------4 Wk--------- <>Placebo-

IGF-I (nmol/liter) 24.6 � 3.0 / 89.6 � 12.21/ 106.3 � 16.41<> 25.8 � 2.7-- 25.4 � 2.7-- 25.2 � 2.6

ft3 (pmol/liter) 5.1 � 0.3 6.0 � 0.12 6.1 � 0.22 4.8 � 0.2 4.9 � 0.2 4.8 � 0.1

fT4 (pmol/liter) 15.5 � 1.5 11.5 � 1.02 10.6 � 0.92 15.8 � 1.6 15.6 � 1.7 15.8 � 1.5

Testosterone(nmol/liter) 18.3 � 3.2 18.5 � 3.4 18.5 � 3.3 16.7 � 2.6 16.3 � 2.6 16.4 � 2.2

Glucose (mmol/liter) 4.7 � 0.3 5.5 � 0.5 5.3 � 0.2 4.5 � 0.4 4.2 � 0.2 4.4 � 0.3

Insulin (mU/liter) 7.9 � 1.6 22.6 � 3.92 16.0 � 9.32 6.0 � 0.3 5.6 � 1.9 9.3 � 2.4

HOMA IR 1.4 � 0.2 5.1 � 1.02 3.3 � 0.62 1.1 � 0.4 1.0 � 0.3 1.6 � 0.5

Total cholesterol (mmol/liter) 4.3 � 0.3 4.0 � 0.5 4.1 � 0.3 3.4 � 0.3 3.3 � 0.3 3.5 � 0.6

Triglyceride 1.1 � 0.2 2.0 � 0.5 1.3 � 0.1 0.6 � 0.1 0.7 � 0.1 0.5 � 0.1

LDL cholesterol (mmol/liter) 2.6 � 0.3 2.2 � 0.3 2.3 � 0.3 1.6 � 0.4 1.6 � 0.3 1.6 � 0.5

HDL cholesterol (mmol/liter) 1.2 � 0.1 1.0 � 0.1 1.1 � 0.1 1.5 � 0.1 1.5 � 0.1 1.7 � 0.2

Body weight (kg) 74.4 � 1.1 76.5 � 1.72 77.9 � 1.62 74.9 � 3.4 74.9 � 3.4 74.7 � 3.3

Lean body mass (kg) 57.6 � 1.1 61.0 � 1.22 61.6 � 2.5 61.8 � 2.4

Total body fat (kg) 11.4 � 1.4 11.6 � 1.7 9.8 � 1.9 10.1 � 2.0

Trunk fat (kg) 4.7 � 0.7 4.5 � 0.9 2.8 � 0.9 2.8 � 0.9

----------------------------

Handbook of Physiology. Sect 7: Endocrinology. Vol IV.
The Pituitary Gland and Its Neuroendocrine Control.
American Physiological Society.

Regulation of somatrotrophic hormone secretion.

Reichlin S.

Clin Endocrinol (Oxf). 1989 Apr;30(4):443-50.

The half-life of exogenous growth hormone after suppression of endogenous growth hormone secretion with somatostatin.

Hindmarsh PC, Matthews DR, Brain CE, Pringle PJ, di Silvio L, Kurtz AB, Brook CG.

Frontiers in Neuroendocrinology, Vol 10.

Some clinical considerations of growth hormone and growth hormone-releasing hormone.

VanceML, Thorner MO.

Science. 1981 Jun 12;212(4500):1279-81.

Somatomedin-C mediates growth hormone negative feedback by effects on both the hypothalamus and the pituitary.

Berelowitz M, Szabo M, Frohman LA, Firestone S, Chu L, Hintz RL.

Endocrinology. 1983 Oct;113(4):1319-24.

Human growth hormone and somatomedin C suppress the spontaneous release of growth hormone in unanesthetized rats.

Abe H, Molitch ME, Van Wyk JJ, Underwood LE.

Neuroendocrinology. 1994 Mar;59(3):251-64.

Growth hormone-releasing hormone and somatostatin neurons within the porcine and bovine hypothalamus.

Leshin LS, Barb CR, Kiser TE, Rampacek GB, Kraeling RR.

Biochem Biophys Res Commun. 1982 Nov 30;109(2):562-7.

Physiological roles of somatocrinin and somatostatin in the regulation of growth hormone secretion.

Wehrenberg WB, Ling N, B�hlen P, Esch F, Brazeau P, Guillemin R.

C R Seances Acad Sci III. 1982 Nov 29;295(11):651-4.

Somatomedin inhibition of the growth hormone secretion stimulated by the hypothalamic factor somatocrinin or the synthetic peptide hpGRF.

Brazeau P, Guillemin R, Ling N, van Wyk J, Humbel R.

Endocrinology. 1984 Nov;115(5):1952-7.

The interrelationship of growth hormone (GH)-releasing factor and somatostatin in generation of the ultradian rhythm of GH secretion.

Tannenbaum GS, Ling N.

Domest Anim Endocrinol. 2004 Apr;26(3):177-88.

Rapid suppressing action of insulin-like growth factor-I (IGF-I) on GH release from anterior pituitary cells of goats.

Katoh K, Shimoguchi R, Ishiwata H, Obara Y.

Clearly Established.

Eur J Endocrinol. 2019 Jun;156(6):647-53.

Pharmacokinetics and pharmacodynamics of GH: dependence on route and dosage of administration.

Keller A, Wu Z, Kratzsch J, Keller E, Blum WF, Kniess A, Preiss R, Teichert J, Strasburger CJ, Bidlingmaier M.

Hospital for Children and Adolescents, University of Leipzig, Oststr. 21-25, D-04317 Leipzig, Germany.

OBJECTIVE: Pharmacokinetic and pharmacodynamic data after recombinant human GH (rhGH) administration in adults are scarce, but necessary to optimize replacement therapy and to detect doping. We examined pharmacokinetics, pharmacodynamics, and 20 kDa GH after injection of rhGH at different doses and routes of administration. DESIGN: Open-label crossover study with single boluses of rhGH. METHODS: Healthy trained subjects (10 males, 10 females) received bolus injections of rhGH on three occasions: 0.033 mg/kg s.c., 0.083 mg/kg s.c., and 0.033 mg/kg i.m. Concentrations of 22 and 20 kDa GH, IGF-I, and IGF-binding proteins (IGFBP)-3 were measured repeatedly before and up to 36 h after injection. RESULTS: Serum GH maximal concentration (C(max)) and area under the time-concentration curve (AUC) were higher after i.m. than s.c. administration of 0.033 mg/kg (C(max) 35.5 and 12.0 mu g/l; AUC 196.2 and 123.8). C(max) and AUC were higher in males than in females (P < 0.01) and pharmacodynamic changes were more pronounced. IGFBP-3 concentrations showed no dose dependency. In response to rhGH administration, 20 kDa GH decreased in females and remained suppressed for 14-18 h (low dose) and 30 h (high dose). In males, 20 kDa GH was undetectable at baseline and throughout the study. CONCLUSIONS: After rhGH administration, pharmacokinetic parameters are mainly influenced by route of administration, whereas pharmacodynamic variables and 20 kDa GH concentrations are determined mainly by gender. These differences need to be considered for therapeutic use and for detection of rhGH doping.

this is very good stuff you beat me to it! sounds like im is the route to go here.

jb

going to metaphysical realms.............

quote:

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[i]In males, 20 kDa GH was undetectable at baseline and throughout the study. [/B]

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Is this the endogenous GH? Or is it only present in females? I think I'm missing something here.

20 kDa GH and 22 kDa GH are the two forms of endo gh, with 22 kDa GH being prominent. non 22 kDa GH is thought to be responsible for short stature so perhaps it is less pronounced in men. The conclusion of this study goes on to say,"Conclusions: After rhGH administration, pharmacokinetic parameters are mainly influenced by route of administration, whereas pharmacodynamic variables and 20 kDa GH concentrations are determined mainly by gender. These differences need to be considered for therapeutic use and for detection of rhGH doping. "

jb