Endocrine factors in the development of transplantable adrenal cortical tumors. I. Inhibition of the growth rate by corticotropin (ACTH)
✍ Scribed by Silvio Fiala; Anna E. Fiala
- Publisher
- John Wiley and Sons
- Year
- 1968
- Tongue
- French
- Weight
- 1003 KB
- Volume
- 3
- Category
- Article
- ISSN
- 0020-7136
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✦ Synopsis
The growth rate of transplantable atlrenocortical tumors in male LAF I mice was fi)irnd to be inhibited in hypophysectomized and in adrenalectomized animals. Castration and sex hormones did not affect the growth of these tumors. /ti intact mice a striking inhibition of the growth rate of adrenocortical tumors was brought about by the administration of ACTH. Evidence was obtained that ACTH inhibited growth by a direct action on the tumor cells. When expressed in t e r m of units of DNA, the biochemical and cytochemical eflects on adrenocortical tunior cells appeared qualitatively similar t o the effects of this hormone on the normal adrlrenal cortex. A single injection of ACTH stimulated the activity of glucose-6-phosphate dehydrogenase. Repeated administration of ACTH produced an increased oxygen uptake by sliced tissue and a moderate accuniulation of RNA in the microsomal fraction. Water extracts of acetone powdered, ACTHtreated, adrenocortical tumors had lower dCMP-deaniinase activity than extracts from untreated tuniors. When expressed in terms of units of DNA, the homogenates of ACTH-treated adrenocortical tumors had a higher succinoxidase activity and the sliced tissue had a lower rate of anaerobic glycolysis than did corresponding saniples of untreated adrenocortical tumors.