Growth Hormone Activity of the Anterior Pituitary Lobe of the Male Rat at Various Ages

Nature ◽  
1961 ◽  
Vol 192 (4806) ◽  
pp. 976-977 ◽  
Author(s):  
R. H. BOWMAN
1977 ◽  
Vol 85 (1) ◽  
pp. 1-10 ◽  
Author(s):  
E. C. Griffiths ◽  
S. L. Jeffcoate ◽  
D. T. Holland

ABSTRACT With the availability of a sensitive and specific radioimmunoassay for growth hormone-release-inhibiting hormone (somatostatin or GH-RIH), it has been possible to investigate the presence of peptidase enzymes capable of inactivating this hypothalamic hormone in the hypothalamus and other brain areas of the rat. It was found that both supernatant and particulate fractions from male rat hypothalami rapidly inactivated somatostatin and that the enzymes involved have an optimum pH of 7.3. Peptidase activity was significantly higher in the supernatant than in the particulate fraction from the hypothalamus, thalamus, cortex and cerebellum. Besides confirming the presence of peptidases inactivating the release-inhibiting hormone in the hypothalamus (the site of somatostatin synthesis and release), the results may indicate that somatostatin has a functional significance outside the hypothalamus-anterior pituitary axis but within the central nervous system.


1970 ◽  
Vol 63 (2) ◽  
pp. 378-384 ◽  
Author(s):  
D. R. Hodges ◽  
W. H. McShan

ABSTRACT Electrophoretic analyses of rat, mouse, human and cow anterior pituitary homogenates with subsequent bioassays for hormonal activity have been reported. Comparison of the behaviour of the hormonal activities from rat anterior pituitary secretory granules and that reported for pituitary homogenates was made following disc electrophoresis on polyacrylamide gels. Bioassays of gel segments for the six anterior pituitary hormones resulted in the localization of the activities of five of the six hormones. ACTH activity was not detected. Growth hormone and prolactin were associated with the major cathodal and anodal discs respectively. Luteinizing hormone and thyroid stimulating hormone activities had similar mobilities and were located in a zone just above growth hormone. The activity was not restricted to a discrete, stainable disc in either case. Follicle stimulating hormone activity was detected in a narrow segment containing only one disc a few millimeters below growth hormone. Comparison of the mobilities of the hormones from homogenates and secretory granule extracts suggests that they have essentially similar electrophoretic characteristics at basis pH.


1969 ◽  
Vol 45 (2) ◽  
pp. 245-256 ◽  
Author(s):  
F. J. EBLING ◽  
ERIKA EBLING ◽  
J. SKINNER

SUMMARY Testosterone implants releasing about 0·2 mg./day had no effect on sebum production in hypophysectomized-castrated rats, even though treatment by a similar dose of testosterone has been shown to effect a marked increase in sebaceous activity in rats with intact pituitaries. A preparation of porcine growth hormone, and a preparation of prolactin (luteotrophin) which had no growth hormone activity, were each capable of fully restoring the response of the sebaceous gland in hypophysectomized male rats to testosterone, though the pituitary hormones had no effect by themselves. The stimulation of sebaceous activity was measured both by the increase in sebum production and by the increased incidence of cell division in the sebaceous glands. The responses of the preputial glands and seminal vesicles to testosterone were independent of the presence of the pituitary, and were not significantly enhanced by the hypophysial hormones.


1961 ◽  
Vol 37 (2) ◽  
pp. 176-182 ◽  
Author(s):  
Elliott J. Collins ◽  
Vernon F. Baker

ABSTRACT The characteristics and nature of the effect of growth hormone on the incorporation of radio-sulfate into the costal cartilage of hypophysectomized rats has been studied. The time-response studies indicate that a reliable estimation of growth hormone activity can be ascertained within a 24 hour period, and a reproducible dose-related response can be obtained at dosage levels ranging from 12-48 μg. Growth hormone stimulates the synthesis of organic sulfates and accumulation of inorganic sulfates within 48 hours.


1965 ◽  
Vol 49 (1) ◽  
pp. 1-16 ◽  
Author(s):  
M. Apostolakis

ABSTRACT A method for the extraction of prolactin from human pituitary glands is described. It is based on acetone drying, distilled water extraction, acetone and isoelectric precipitation. Two main products are obtained: Fraction R8 with a mean prolactin activity of 12.2 IU/mg and fraction U8 with a mean prolactin activity of 8.6 IU/mg. The former fraction does not contain any significant gonadotrophin activity and the latter contains on an average 50 HMG U/mg. In both cases contamination with ACTH and MSH is minimal. The growth hormone activity of both these fractions is low. It is postulated that in man too, prolactin and growth hormone are two distinct hormones. A total of 1250 human pituitary glands have been processed by this method. The mean prolactin content per pituitary gland has been found to be 73 IU.


Metabolism ◽  
1967 ◽  
Vol 16 (9) ◽  
pp. 830-845 ◽  
Author(s):  
A.C. Nadler ◽  
M. Sonenberg ◽  
M.I. New ◽  
C.A. Free

1973 ◽  
Vol 134 (4) ◽  
pp. 1103-1113 ◽  
Author(s):  
A. Betteridge ◽  
M. Wallis

The effect of insulin on the incorporation of radioactive leucine into growth hormone was investigated by using rat anterior pituitary glands incubated in vitro. A 50% stimulation over control values was observed at insulin concentrations above 2μm (280munits/ml). The effect was specific for growth hormone biosynthesis, over the range 1–5μm-insulin (140–700munits/ml). Lower more physiological concentrations had no significant effect in this system. Above 10μm (1.4 units/ml) total protein synthesis was also increased. The stimulation of growth hormone synthesis could be partially blocked by the addition of actinomycin D, suggesting that RNA synthesis was involved. Insulin was found to stimulate the rate of glucose utilization in a similar way to growth hormone synthesis. 2-Deoxyglucose and phloridzin, which both prevented insulin from stimulating glucose utilization, also prevented the effect of insulin on growth hormone synthesis. If glucose was replaced by fructose in the medium, the effect of insulin on growth hormone synthesis was decreased. We conclude that the rate of utilization of glucose may be an important step in mediating the effect of insulin on growth hormone synthesis.


1953 ◽  
Vol 54 (3) ◽  
pp. 407-413 ◽  
Author(s):  
A. L. Greenbaum ◽  
Patricia McLean

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