scholarly journals The time of onset of mitotic activity in the adrenal cortex of the hypophysectomized rat following injections of growth hormone

1955 ◽  
Vol 127 (2) ◽  
pp. 273-279 ◽  
Author(s):  
D. B. Cater ◽  
M. P. Stack-Dunne
1971 ◽  
Vol 51 (3) ◽  
pp. 473-481 ◽  
Author(s):  
H. M. LLOYD ◽  
J. D. MEARES ◽  
JOAN JACOBI ◽  
FRANCES J. THOMAS

SUMMARY A single 12 mg dose of stilboestrol dipropionate given to 100-day-old male rats resulted in increased pituitary mitotic activity, pituitary weight and serum growth hormone; the latter rose from a mean value of 20 ng/ml to a maximum of 342 ng/ml 9 days later. Serum growth hormone and pituitary mitotic activity then gradually diminished but were still slightly increased on day 28. Serum growth hormone and pituitary weight were significantly correlated during the periods of rapidly rising and of sustained high levels of serum growth hormone. Indices of mitotic activity were correlated with serum growth hormone during the periods of rapidly rising and of falling levels of serum growth hormone.


1973 ◽  
Vol 58 (2) ◽  
pp. 227-231 ◽  
Author(s):  
H. M. LLOYD ◽  
J. D. MEARES ◽  
JOAN JACOBI

SUMMARY The effects of a single injection of 1 mg diethylstilboestrol dipropionate on pituitary mitotic activity and on secretion of growth hormone and prolactin were investigated in male rats on each of the first 15 days following the single dose and then at intervals for a total period of 63 days. Mitotic activity increased to a maximum on day 4 and then gradually diminished. Serum growth hormone was moderately increased during the 2nd week and serum prolactin showed a gradual rise with a return to normal on day 63. In the pituitary gland, growth hormone concentration diminished until day 28, whereas prolactin rose quickly at first, maintained a raised level and increased further on day 43. During the first 12 days, pituitary weight was significantly correlated with serum growth hormone and prolactin concentration. During days 13–28, serum prolactin, but not growth hormone, was significantly correlated with the pituitary mitotic index.


Blood ◽  
1952 ◽  
Vol 7 (2) ◽  
pp. 193-206 ◽  
Author(s):  
GERALD F. HUNGERFORD ◽  
WILLIAM O. REINHARDT ◽  
CHOH HAO LI

Abstract The endocrine influences of hypophysectomy, adrenalectomy, and the administration of pituitary and adrenal hormones on the level of thoracic duct lymphocytes have been studied in test animals under standardized conditions. The following effects have been noted: 1. Numbers of thoracic duct lymphocytes are elevated after either hypophysectomy or adrenalectomy in the rat. 2. After the administration of either ACTH protein or pepsin peptide mixtures to normal or hypophysectomized rats, the number of thoracic duct lymphocytes is significantly reduced. This effect was not noted in adrenalectomized rats. These effects were observed two hours after administration of the ACTH preparations. If a shorter time elapsed, no effect was noted with the ACTH protein, nor was any effect noted with an ACTH acid peptide mixture under the conditions employed. 3. Administration of epinephrine to normal or hypophysectomized rats, singly or in combination with ACTH protein (in which case its effect was potentiated), produced a significant reduction in the number of thoracic duct lymphocytes. This effect was not observed in the adrenalectomized rat, suggesting that epinephrine may act directly in producing this effect. 4. Growth hormone (beef anterior pituitary), Pitressin, Pitocin, Adrenal Cortex Extract, cortisone acetate, and desoxycorticosterone glucoside did not alter the levels of thoracic duct lymphocytes under the conditions of these experiments.


1955 ◽  
Vol 12 (3) ◽  
pp. 174-184 ◽  
Author(s):  
D. B. CATER ◽  
M. P. STACK-DUNNE

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.


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