Growth hormones, orally administrable

Type IV poly(ortho esters) are very similar in structure to type II poly(ortho esters), but they do not need to have excipients in the formulation due to the incorporation of no acidic moieties in the polymer backbone (Ng et al. 1997). Rods of poly(ortho ester) loaded with recombinant human-growth hormone and bovine serum albumin have been created. The rods are the products of polymer-protein mixture extrusion at a temperature between 50° and 70°C. Particles have also been produced from these rods (Heller et al. 2000). The size of these particles, >106 pm, was much larger than would be expected to be absorbed by the gastrointestinal lining (Florence 1997). If the particle size can be reduced, this type of polymer system may be made to be acceptable for oral administration. 

Jacobs AJ, Odom MJ, Word RA, Carr BR. Effect of oral 182. contraceptives on adrenocorticotropin and growth hormone secretion following CRH and GHRH administration. Contraception 1989 40(6) 691-9. 

Serum growth hormone levels were dose-dependently increased after oral and intravenous administration. Moreover, an increase of insulin-like growth factor and serum cortisol was found. Clearly, the pituitary incubation method can only identify compounds which are suitable for further in vivo characterization, because the responses found in test animals at the target organ level are vast different from those found at the pituitary cell level. 

Orally administrable nonpeptide oxindole derivatives, (HI), prepared by Tokunago (4) were effective in stimulating the release of growth hormone factor. 

Tryptophan administration orally to 14 normal subjects induced a rise in plasma glucose accompanied by a rise in plasma glucagon levels and also by increased concentrations of circulating insulin and growth hormone.84 The increase in plasma glucose due to tryptophan in humans differs from the reported hypoglycemic effect in rats. 

The only potential human health concern related to cows treated with BST was the possible increase in the level of a second peptide hormone related to the action of growth hormone, insulin-like growth factor-I (IGF-I). IGF-I is a 70 amino acid peptide and, in many respects, is structurally similar to insulin. When the milk from BST-treated cows was assayed for IGF-I, it had concentrations comparable to that found in human breast milk and well within normal levels of biological exposure. Since it is a large peptide similar to insulin and BST, IGF-I also is not absorbed after oral administration for all the reasons discussed above. However, there was still concern regarding its presence in infant formula because of the increased exposure and vulnerability of babies. Further studies showed that any IGF-I present in milk from normal or BST-treated cows was destroyed in the formula manufacturing process. Again the safety of BST-treated milk was demonstrated ... 

Bowers, C.Y., D.K. Alster J.M. Frentz. 1992. The growth hormone-releasing activity of a synthetic hexapeptide in normal men and short statured children after oral administration. J. Clin. Endocrinol. Metab. 74 292-8. 

Overall, nutrition therapy is a component of medical treatment that includes oral, enteral, and parenteral nutrition (PN). However, a meta-analysis provided no evidence that nutritional support has a significant effect on anthropometric measures, lung function, or exercise capacity in patients with stable COPD (25,26). By contrast, repeated administration of ghrelin, a novel growth hormone- releasing peptide that is reduced in COPD (27), may improve body composition, muscle wasting, and functional capacity in cachectic patients with COPD, thus possibly reversing some of the systemic aspects of COPD (28). 

Isidori A, Lo Monaco A, Cappa M. A study of growth hormone release in man after oral administration of amino acids. Curr Med Res Opin 1981 7 475-481. 

Chapman, I.M., Pescovitz, O.H., Murphy, G, et al. (1997) Oral administration of growth hormone (GH) releasing peptide-mimetic MK-677 stimu-... 

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