Growth hormone is produced within the hippocampus where it responds to age, sex and stress.
 Proc. Natl Acad. Sci. USA V.103. №15. Р.6031–6036 (2006) | |||
) Рис.1. | Age and sex differences in GH expression. (A) GH mRNA levels are depicted as a function of age (adult vs. juvenile) and sex [males (filled bars) vs. females (open bars)]. Levels were increased in adults, especially in females. (B) The expression of GH mRNA in females is depicted during stages of estrus, including proestrus (PF), estrus (EF), and diestrus (DF), and compared with expression in adult males (AM). They were increased in females during proestrus and estrus. (C) Examples of a Western blot are shown, illustrating the presence of GH protein in the hippocampus, especially in females during estrus. JM, juvenile males; JF, juvenile females ) Рис.2. | GHRs and expression of IGF-I. (A) GHR (filled bars) and IGF-I (open bars) mRNA levels are presented as a function of age and sex differences. mRNAs for both were decreased in females during proestrus (PF), relative to females in estrus (EF) and diestrus (DF), as well as in adult males (AM). (B) A scatterplot analysis shows the expression of GHR vs. IGF-I for all animals. The data suggest a strong positive correlation between the expression of the GHR and IGF-I. ) Рис.3. | Estrogen stimulates GH production. (A) Ovariectomized females injected with an oil vehicle (OVX w/O) produced similar levels of GH as adult males but twice as much GH upon exposure to 17-β-estradiol relative to untreated controls. (B) RT-PCR products from amplification of cDNA generated from the total RNA of untreated 1-week-old primary neuronal cultures and from the same cultures treated with 10 nM 17-β-estradiol relative to untreated controls. (B) RT-PCR products from amplification of cDNA generated from the total RNA of untreated 1-week-old primary neuronal cultures and from the same cutures treated with 10 nM 17-β-estradiol relative to untreated controls. (B) RT-PCR products from amplification of cDNA generated from the total RNA of untreated 1-week-old primary neuronal cultures and from the same cultures treated with 10 nM 17- FPRIVATE "TYPE=PICT;ALT=beta"β-estradiol for 24 h. ) Рис.4. | Estrogen stimulates GH production. (A) GH mRNA levels were increased in cortical neurons upon exposure to 10 nM 17- βestradiol relative to untreated controls. (B) RT-PCR products from amplification of cDNA generated from the total RNA of untreated 1-week-old primary neuronal cultures and from the same cultures treated with 10 nM 17-β-estradiol for 24 h. ) Рис.5. | Stress induces GH production. (A) Males exposed to an acute stressful event produced twice as much GH mRNA as males that received no stress, although IGF levels were unchanged. (B) Females exposed to a stressor during diestrus produced more than three times as much GH mRNA and 20% of IGF mRNA. (C) GH and IGF mRNA in those stressed during estrus were unaffected. |
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