A new bioassay for human growth hormone based on incorporation of labelled proline into skin

An in-vivo bioassay for human growth hormone (hGH) has been developed, based on the dose-related enhancement of radioactivity in skin of hypophysectomized rats given daily s.c. injections of hGH and a single i.p. injection of labelled proline. The measured radioactivity, taken as the response, was shown to be independent of the site at which the skin was sampled. Valid dose–response relationships were obtained after as little as 3 days of treatment with GH. The assays by this method are shown to be more precise than the widely used weight-gain and tibial-width bioassays. Assays carried out gave an average index of precision of 0·036.

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Reduced and S-carboxymethylated human growth hormone: a probe for diabetogenic action

AJP Endocrinology and Metabolism ◽

10.1152/ajpendo.1984.247.5.e639 ◽

1984 ◽

Vol 247 (5) ◽

pp. E639-E644

Author(s):

C. M. Cameron ◽

J. L. Kostyo ◽

J. A. Rillema ◽

S. E. Gennick

Keyword(s):

Growth Hormone ◽

Amino Acid ◽

Human Growth Hormone ◽

Human Growth ◽

Mouse Mammary Gland ◽

Amino Acid Incorporation ◽

Acid Incorporation ◽

Hypophysectomized Rats

The biological activity profile of reduced and S-carboxymethylated human growth hormone (RCM-hGH) was determined to establish its suitability for study of the diabetogenic property of hGH. RCM-hGH was found to have greatly attenuated in vivo growth-promoting activity in the 9-day weight-gain test in hypophysectomized rats (approximately 1%) and to have a similar low order of in vitro activity in stimulating amino acid incorporation into the protein of the isolated rat diaphragm. RCM-hGH also only had approximately 1% of the in vitro insulin-like activity of the native hormone on isolated adipose tissue from hypophysectomized rats. In contrast, RCM-hGH retained substantial in vivo diabetogenic activity in the ob/ob mouse, appearing to have approximately 50% of the activity of the native hormone. RCM-hGH was also found to retain significant, although attenuated (25%), in vitro lactogenic activity when tested for the ability to stimulate amino acid incorporation into a casein-rich protein fraction in mouse mammary gland explants. Because RCM-hGH exhibits a high degree of diabetogenic activity, although lacking significant anabolic or insulin-like activities, it will be useful as a "monovalent" probe for the study of the molecular mechanism of the diabetogenic action of GH.

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IN VITRO AND IN VIVO EFFECT OF GROWTH HORMONE ON ALDOSTERONE SECRETION

Canadian Journal of Biochemistry and Physiology ◽

10.1139/y60-133 ◽

1960 ◽

Vol 38 (1) ◽

pp. 1069-1075

Author(s):

O. J. Lucis ◽

E. H. Venning

Keyword(s):

Growth Hormone ◽

Adrenal Gland ◽

Human Growth Hormone ◽

Human Growth ◽

Secretion Rate ◽

Aldosterone Secretion ◽

Hypophysectomized Rats

Porcine, monkey, and human growth hormone have no effect on the in vitro secretion of aldosterone by the rat adrenal gland. When monkey growth hormone is injected into hypophysectomized rats, the adrenals of these animals secrete, under in vitro conditions, increased amounts of aldosterone with no change in the secretion rate of corticosterone. The plasma of these rats contains a substance which appears to stimulate the secretion of aldosterone in the adrenals of normal rats.

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