Circulating levels of growth hormone, insulin-like growth factor-I and prolactin in normal, growth retarded and anencephalic human fetuses

1995 ◽  
Vol 18 (5) ◽  
pp. 346-353 ◽  
Author(s):  
M. Arosio ◽  
D. Cortelazzi ◽  
L. Persani ◽  
E. Palmieri ◽  
G. Casati ◽  
...  
Keyword(s):  
Growth Hormone ◽  
Growth Factor ◽  
Normal Growth ◽  
Insulin Like Growth Factor ◽  
Human Fetuses ◽  
Factor I ◽  
Growth Factor I ◽  
Circulating Levels

Insulin-like growth factor I and growth hormone in canine starvation

1985 ◽  
Vol 108 (2) ◽  
pp. 161-166 ◽  
Author(s):  
J. Eugen Eigenmann ◽  
Jan. J. de Bruijne ◽  
E. Rudolf Froesch
Keyword(s):  
Growth Hormone ◽  
Growth Factor ◽  
Insulin Like Growth Factor ◽  
Drastic Reduction ◽  
Factor I ◽  
Igf I ◽  
Growth Factor I ◽  
Plasma Gh ◽  
Circulating Levels ◽  
Secretory Capacity

Abstract. The roles of plasma insulin-like growth factor I (IGF I) and growth hormone (GH) were studied in 7 beagle dogs before and during starvation and during refeeding. IGF I levels significantly decreased from 75.2 ± 5.9 ng/ml at 7 days prior to the start of starvation to 9 ± 1.7 ng/ml at 19 days after the commencement of starvation (mean ± sem; P < 0.0001). During refeeding IGF I significantly rose from 9 ± 1.7 ng/ml to 55.5 ± 7.5 ng/ml within 9 days (mean ± sem; P < 0.002). During starvation plasma GH levels significantly increased (P < 0.05) and these elevated levels returned to normal during refeeding. The dogs' GH secretory capacity significantly increased during starvation (P = 0.012) and became normal again during refeeding. The following conclusions can be drawn from this study: 1) starvation in the dog leads to a significant and drastic reduction of the circulating levels of IGF I, and 2) starvation in the dog, as in man, leads to increased circulating GH levels and to an increased GH-secretory capacity possibly brought about by a lack of a negative feedback normally exerted by IGF I.

Influence of circulating insulin-like growth factor-I compared with that of intrarenal insulin-like growth factor-I on proximal nephron receptor density in rats

1992 ◽  
Vol 83 (2) ◽  
pp. 233-239 ◽  
Author(s):  
Michael K. Hise ◽  
Quintina Corteza ◽  
David K. Klassen ◽  
John H. Sadler
Keyword(s):  
Growth Hormone ◽  
Growth Factor ◽  
Dietary Protein ◽  
Dominant Role ◽  
Scatchard Analysis ◽  
Insulin Like Growth Factor ◽  
Receptor Density ◽  
Factor I ◽  
Growth Factor I ◽  
Circulating Levels

1. We examined the effects of dietary protein manipulations in partially nephrectomized (one and one-third nephrectomy) and normal rats to gain perspective on the relative importance of circulating versus intrarenal (collecting tubule) insulin-like growth factor-I in the control of proximal nephron receptor density. In addition, we studied the factors that influence liver insulin-like growth factor-I secretion in partially nephrectomized rats. 2. Dietary protein restriction (6% versus 40%) lowered circulating levels of insulin and insulin-like growth factor-I in both normal and partially nephrectomized rats up to 3 weeks after institution of the diets; however, growth hormone levels were little changed. Reduced renal mass stimulated intrarenal production of insulin-like growth factor I regardless of the diet. 3. Scatchard analysis revealed that the density of insulin-like growth factor-I receptors on glomerular and proximal tubule basolateral membranes increased when circulating levels of insulin-like growth factor-I were diminished, despite raised levels of intrarenal insulin-like growth factor-I, in partially nephrectomized rats. 4. Circulating insulin-like growth factor-I, rather than the tissue level, plays the dominant role in the control of proximal nephron receptor density under physiological conditions. Insulin, but not growth hormone, may play a role in liver insulin-like growth factor-I secretion in partially nephrectomized rats during dietary manipulations.

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