Mitotic activity in the pancreatic islets of the rat under pituitary growth hormone and adrenocorticotropic hormone treatment

1953 ◽  
Vol 66 (1) ◽  
pp. 147-150 ◽  
Author(s):  
Cesare Cavallero ◽  
Leonardo Mosca
Keyword(s):  
Growth Hormone ◽  
Pancreatic Islets ◽  
Mitotic Activity ◽  
Adrenocorticotropic Hormone ◽  
Hormone Treatment ◽  
Pituitary Growth Hormone

THE EFFECTS OF GROWTH HORMONE AND CORTICOTROPHIN UPON THE ADRENAL WEIGHT AND ADRENOCORTICAL MITOTIC ACTIVITY IN THE HYPOPHYSECTOMIZED RAT

1955 ◽  
Vol 12 (3) ◽  
pp. 174-184 ◽  
Author(s):  
D. B. CATER ◽  
M. P. STACK-DUNNE
Keyword(s):  
Growth Hormone ◽  
Cell Division ◽  
Mitotic Activity ◽  
Great Increase ◽  
Adrenal Weight ◽  
Synergic Effect ◽  
Single Test ◽  
Pituitary Growth Hormone ◽  
Artificial Mixtures ◽  
Stimulation Of

SUMMARY 1. Treatment of rats 17–24 days after hypophysectomy with pituitary growth hormone for 3 days causes a definite, although limited, increase in adrenal weight. When growth hormone and corticotrophin are given simultaneously, the increase in adrenal weight is greater than the sum of the effects with the hormones separately. The larger the dose of corticotrophin the greater the synergic effect. 2. The action of growth hormone on the adrenal is characterized by a striking stimulation of cell division with relatively little effect on adrenal weight. Corticotrophin also stimulates adrenocortical mitotic activity, but to obtain mitotic activity equivalent to that with growth hormone, doses must be given sufficient to cause a great increase in adrenal weight. This is true whether corticotrophin is injected in saline or in a beeswax/arachis oil mixture. 3. The characteristic activity of each preparation in stimulating the adrenal can be expressed in terms of a quotient, Qmw, the ratio of mitosis-stimulating activity to increase of adrenal weight in a single test. This index is effectively independent of the absolute responses. For growth hormone, Qmw is high; for biologically pure corticotrophin, it is low. Artificial mixtures of the two hormones give intermediate values of the quotient; crude corticotrophin preparations give values higher than those for purified preparations.

THE EFFECT OF PITUITARY GROWTH HORMONE ON THE LEVEL AND TURNOVER OF NUCLEIC ACIDS AND PHOSPHOLIPIDS OF THE RAT'S LIVER

1957 ◽  
Vol 15 (3) ◽  
pp. 235-242 ◽  
Author(s):  
A. L. GREENBAUM ◽  
C. N. GRAYMORE ◽  
T. F. SLATER
Keyword(s):  
Growth Hormone ◽  
Turnover Rate ◽  
Deoxyribonucleic Acid ◽  
Control Level ◽  
Hormone Treatment ◽  
Phospholipid Content ◽  
Lag Phase ◽  
Turnover Rates ◽  
Pituitary Growth Hormone ◽  
Cytoplasmic Rna

SUMMARY The levels of deoxyribonucleic acid (DNA), ribonucleic acid (RNA), phospholipid and phosphoprotein and the turnover rates of DNA, nuclear and cytoplasmic RNA, and phospholipid, have been studied in the livers of rats treated with growth hormone for 12 hr or 3 days. There was no change in either the level or turnover of DNA. After a lag phase the level of RNA rose some 30% above control level and similar rises were noted in the turnover rate. The phospholipid content and turnover also increased as a result of the hormone treatment. There was a fall in the level of the phosphoprotein fraction. These results are discussed in relation to the increased rate of protein synthesis found in growth hormone-treated rats.

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