Isolation, purification, and characterization of gamma-lipotropic hormone from sheep pituitary glands

The isolation and characterization of a new biologically active polypeptide from sheep pituitary glands is described. Considerable evidence suggests that the structure of the new molecule, designated γ-lipotropin, is identical with the N-terminal portion (sequence 1–58) of β-lipotropin and, therefore, that γ-lipotropin contains at its C-terminus the amino acid sequence of β-melanophore-stirnulating hormone (β-MSH). The implications of these results are discussed in relation to the mechanism of pituitary peptide biosynthesis and to the structure–activity relationships between sheep β-MSH and lipotropic hormones.

Retention of the biological potency of human pituitary growth hormone after reduction and carbamidomethylation

The reduced alkylated derivative of human pituitary growth hormone was prepared by reacting the native hormone in 8M urea solution, first with mercaptoethanol and then with iodoacetamide. On the basis of amino acid analyses, the product isolated after gel filtration on Sephadex G-100 is completely devoid of unreduced cystine but otherwise has a composition identical to that of the native hormone. When assayed in both the rat tibia test and the pigeon crop-sac assay,it appears that the full potency of the native hormone is retained in the reduced alkylated derivative.

Achondroplastic dwarfism. Effects of treatment with human growth hormone

Two male patients with achondroplastic dwarfism aged 7-5/12 and 14(1/2) years were treated with human growth hormone 5 mg daily. Both showed nitrogen retention on balance studies, the older second patient to a marked degree. In the younger patient, height increased from 95.4 to 106.3 cm on hgh 5 mg daily alone for 14 out of 24 months. The rate of growth approximately doubled during the first two treatment periods as compared with the pre-treatment rate. In the second older patient hgh was administered 5 mg daily intramuscularly for 21 out of 33 months. Growth from 129.6 cm to 137.8 cm occurred with the rate increasing following the addition of Na-1-thyroxine to the routine. This increased growth rate occurred during the post-puberty deceleration phase. Bone ages, interpreted from changes in the phalanges and metacarpals, increased from 4(1/2) to 6 years during 16 months in Case 1, and from 13(1/2) to 18 years in 33 months in Case 2. Transient adolescent gynecomastia appeared in Case 2. No local or general toxic effects were noted. These results are suggestive, but whether or not the eventual height of an achondroplastic dwarf can be significantly altered must await further studies.