INACTIVITY OF ACID-EXTRACTED GROWTH HORMONE INJECTED IN AQUEOUS SUSPENSION
Autor: | E. A. Lazo-Wasem, Joan Michalski, Claire E. Graham |
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Rok vydání: | 1958 |
Předmět: | |
Zdroj: | Endocrinology. 63:831-835 |
ISSN: | 1945-7170 0013-7227 |
Popis: | The somatotropic activity of alkali- and acid-extracted growth hormone stored at various pH's was tested. The U.S.P. Growth Hormone Reference Standard, an alkali-extracted preparation, was found to lose most of its activity when stored at pH 3. Maximum stability was found at pH 11. No significant loss in activity was found between pH 5 and pH 11. Acid-extracted growth hormone showed the same activity at pH 3 or pH 11, but full activity was only found when the material was injected as a clear solution. Aqueous suspensions of acid-extracted growth hormone were found to be inactive. This effect was also evident after intravenous assay. It is concluded that alkali-extracted growth hormone such as the U.S.P. Growth Hormone Reference Standard should never be exposed to pH's below 5 or above 11, while acid-extracted growt hormone, although not affected adversely by pH's as low as 3, should only be injected as a clear solution. |
Databáze: | OpenAIRE |
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