Mild Calorie Restriction Does Not Affect Testosterone Levels and Testicular Gene Expression in Mutant Mice

2007 ◽  
Vol 232 (8) ◽  
pp. 1050-1063 ◽  
Author(s):  
Juliana S. Rocha ◽  
Michael S. Bonkowski ◽  
Luiz R. França ◽  
Andrzej Bartke
Keyword(s):  
Growth Factor ◽  
Calorie Restriction ◽  
Hormone Receptor ◽  
Reproductive Organs ◽  
Luteinizing Hormone Receptor ◽  
Calorie Intake ◽  
Testicular Function ◽  
Insulin Like Growth Factor ◽  
Somatotropic Axis ◽  
Testosterone Levels

The hypothalamic-pituitary-gonadal (HPG) axis and the somatotropic axis are influenced by nutritional factors. Calorie restriction (CR) extends lifespan but suppresses both the HPG and the somatotropic axes. Since most CR studies use a fairly severe (40%–60%) reduction of calorie intake, we hypothesized that a milder CR (20%) might not be deleterious to reproduction in male mice. To test this hypothesis, we evaluated the effects of 20% CR on testicular testosterone content and on testicular expression of genes that are relevant to testicular function and reproductive competence, including insulin-like growth factor-I, cytochrome P450 aromatase (Cyp19a1), androgen receptor, luteinizing hormone receptor, follicle-stimulating hormone receptor, cytochrome P450c17 and 3-β-hydroxysteroid dehydrogenase/isomerase. To relate CR effects to the activity of the somatotropic axis, we have used growth hormone–resistant GHR knockout mice as well as transgenic mice overexpressing GH. Mild CR did not affect testosterone levels in testis homogenates and had little effect on expression of the examined genes in the reproductive organs. Altered activity of the GH/insulin-like growth factor–1 axis had a major impact on the parameters analyzed. The results also suggest that expression of several key genes involved in the control of testicular function is preserved under conditions of mild CR and encourage speculation that mild regimens of CR can produce longevity benefits without impairing reproduction.

scholarly journals A Role of Insulin-Like Growth Factor I in Luteinizing Hormone Receptor Expression in Granulosa Cells1

Endocrinology ◽  
1999 ◽  
Vol 140 (11) ◽  
pp. 4965-4971 ◽  
Author(s):  
Takashi Hirakawa ◽  
Takashi Minegishi ◽  
Kazuko Abe ◽  
Hiroshi Kishi ◽  
Yoshito Ibuki ◽  
...  
Keyword(s):  
Growth Factor ◽  
Luteinizing Hormone ◽  
Hormone Receptor ◽  
Receptor Expression ◽  
Luteinizing Hormone Receptor ◽  
Insulin Like Growth Factor ◽  
Factor I ◽  
Growth Factor I ◽  
Hormone Receptor Expression

scholarly journals Insulin-like growth factor 1 receptor regulates hypothermia during calorie restriction

2017 ◽  
Vol 114 (36) ◽  
pp. 9731-9736 ◽  
Author(s):  
Rigo Cintron-Colon ◽  
Manuel Sanchez-Alavez ◽  
William Nguyen ◽  
Simone Mori ◽  
Ruben Gonzalez-Rivera ◽  
...  
Keyword(s):  
Growth Factor ◽  
Body Temperature ◽  
Calorie Restriction ◽  
Core Body Temperature ◽  
Insulin Like Growth Factor ◽  
Hypothalamic Nuclei ◽  
The Central Nervous System ◽  
Temperature Homeostasis ◽  
Core Body ◽  
The Brain

When food resources are scarce, endothermic animals can lower core body temperature (Tb). This phenomenon is believed to be part of an adaptive mechanism that may have evolved to conserve energy until more food becomes available. Here, we found in the mouse that the insulin-like growth factor 1 receptor (IGF-1R) controls this response in the central nervous system. Pharmacological or genetic inhibition of IGF-1R enhanced the reduction of temperature and of energy expenditure during calorie restriction. Full blockade of IGF-1R affected female and male mice similarly. In contrast, genetic IGF-1R dosage was effective only in females, where it also induced transient and estrus-specific hypothermia in animals fed ad libitum. These effects were regulated in the brain, as only central, not peripheral, pharmacological activation of IGF-1R prevented hypothermia during calorie restriction. Targeted IGF-1R knockout selectively in forebrain neurons revealed that IGF signaling also modulates calorie restriction-dependent Tbregulation in regions rostral of the canonical hypothalamic nuclei involved in controlling body temperature. In aggregate, these data identify central IGF-1R as a mediator of the integration of nutrient and temperature homeostasis. They also show that calorie restriction, IGF-1R signaling, and body temperature, three of the main regulators of metabolism, aging, and longevity, are components of the same pathway.

Characteristics of first-antler growth in reindeer and their association with seasonal fluctuations in steroid and insulin-like growth factor 1 levels

1998 ◽  
Vol 76 (11) ◽  
pp. 2096-2102 ◽  
Author(s):  
J E Blake ◽  
J E Rowell ◽  
J M Suttie
Keyword(s):  
Growth Factor ◽  
Growth And Development ◽  
Rangifer Tarandus ◽  
Plasma Testosterone ◽  
Insulin Like Growth Factor ◽  
Seasonal Fluctuations ◽  
Testosterone Levels ◽  
Rangifer Tarandus Tarandus ◽  
Antler Growth ◽  
Measurable Growth

Growth and development of the pedicles and first antlers were monitored in seven reindeer (Rangifer tarandus tarandus) calves (three males, four females) from birth to 1 year of age. Calves were weighed, blood was sampled, and antler observations and (or) measurements were taken on the day of birth and days 2, 4, and 7 and then at weekly intervals for the remainder of the year. Prior to measurable growth, the frontal lateral crest was carefully palpated for evidence of pedicle initiation, starting on the day of birth. Calves were born between April 8 and 26, 1994. Pedicle initiation occurred in all reindeer by day 7. Velvet skin first appeared when calves were 4-6 weeks old, when estimated pedicle height was 3.5 ± 0.9 cm (mean ± SD). Antler growth in both sexes followed a sigmoidal pattern, producing a mean antler length of 33.5 ± 4.2 and 46.7 ± 13.8 cm in females and males, respectively. Antler growth was complete by week 18 in females and week 21 in males. Velvet cleaning was associated with a significant increase in plasma testosterone levels in males and estradiol-17beta (but not testosterone) levels in females. Insulin-like growth factor 1 levels were significantly higher in males than in females and were positively correlated with the period of most rapid antler growth in both sexes. Casting occurred between March 14 and April 17, when steroid levels were at a minimum, and was immediately followed by growth of the second antler.

scholarly journals Somatotropic Axis and Obesity: Is There Any Role for the Mediterranean Diet?

Nutrients ◽  
2019 ◽  
Vol 11 (9) ◽  
pp. 2228 ◽  
Author(s):  
Giovanna Muscogiuri ◽  
Luigi Barrea ◽  
Daniela Laudisio ◽  
Carolina Di Somma ◽  
Gabriella Pugliese ◽  
...  
Keyword(s):  
Insulin Resistance ◽  
Growth Hormone ◽  
Growth Factor ◽  
Mediterranean Diet ◽  
Adult Women ◽  
Model Assessment ◽  
Insulin Like Growth Factor ◽  
Somatotropic Axis ◽  
Peak Response ◽  
The Mediterranean

Obesity is associated with reduced spontaneous and stimulated growth hormone (GH) secretion and basal insulin-like growth factor I (IGF-1) levels—which in turn is associated with increased prevalence of cardiovascular risk factors. The aim of this study was to investigate: (1) the association of somatotropic axis with cardiometabolic status; (2) the association of somatotropic axis with the Mediterranean diet and nutritional pattern in people with obesity. Cross-sectional observational study was carried out in 200 adult women, aged 36.98 ± 11.10 years with severe obesity (body mass index—BMI of 45.19 ± 6.30 kg/m2). The adherence to the Mediterranean diet and the total calorie intake was assessed. Anthropometric measurements, body composition and biochemical profile were determined along with Growth Hormone (GH)/Insulin like Growth Factor 1 (IGF-1) axis and insulin resistance (homeostatic model assessment for insulin resistance—HoMA-IR). The enrolled subjects were compared after being divided according to GH peak response and according to IGF-1 standard deviation scores (SDS). Derangements of GH peak were detected in 61.5% of studied patients while IGF-1 deficiency was detected in 71% of the population. Both blunted GH peak response and IGF-1 SDS were indicators of derangements of somatotropic axis and were associated with comparable results in terms of cardiometabolic sequelae. Both GH peak and IGF-1 levels were inversely associated with anthropometric and metabolic parameters. The adherence to the Mediterranean diet predicts GH peak response. Fatty liver index (FLI), fat mass (FM) and phase angle (PhA) were predictive factors of GH peak response as well. In conclusion derangements of somatotropic axis is associated with a worse cardiometabolic profile in people with obesity. A high adherence to the Mediterranean diet—and in particular protein intake—was associated with a better GH status.

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