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[Growth hormone insensitivity of rats under the endotoxemic condition].
- Source :
-
Zhonghua wai ke za zhi [Chinese journal of surgery] [Zhonghua Wai Ke Za Zhi] 2002 Dec; Vol. 40 (12), pp. 940-4. - Publication Year :
- 2002
-
Abstract
- Objective: To investigate the mechanism of growth hormone insensitivity of rats under the endotoxemic condition.<br />Methods: Sprague Dawley rats (n = 180) were injected endotoxin, TNF-alpha, and IL-6 respectively. Part of endotoxin injected rats were treated with exogenous somatotropin simultaneously, and all rats were killed at different time points. Liver expression of IGF I, GHR and SOCS-3 mRNA was detected by RT-PCR, the levels of growth hormone (GH) were measured by radioimmunoassay, and the levels of TNF-alpha and IL-6 were detected by ELISA.<br />Results: Serum GH levels showed no significant change after endotoxin injection; however, liver IGF I and GHR mRNA expressions were obviously down-regulated in endotoxemic rats, with the lowest decrease of 53% and 89% respectively. Although SOCS-3 mRNA was weakly expressed in control rats, it was strongly up-regulated in endotoxemic rats and the marked increase was 7.84 folds. The higher LPS dosage induced marked GHR mRNA down-regulation and marked SOCS-3 mRNA up-regulation. Exogenous GH made IGFI mRNA expression increase 25% in the control rats, but it did fail to prevent the decline in IGFI mRNA expression in endotoxemic rats. Endotoxin stimulated the production of TNF-alpha and IL-6, and the elevated IL-6 levels showed a positive correlation with increased SOCS-3 mRNA expression. Liver GHR mRNA expression was obviously down-regulated after TNF-alpha i.v. injection, but for IL-6, it mainly up-regulated the liver SOCS-3 mRNA expression.<br />Conclusion: The growth hormone insensitivity could be induced by LPS injection, which might be associated with down-regulated GHR mRNA expression and up-regulated SOCS-3 mRNA expression. The in vivo biological activities of LPS may be partially mediated by TNF-alpha and IL-6 at different aspects.
- Subjects :
- Animals
Down-Regulation
Growth Hormone pharmacology
Insulin-Like Growth Factor I genetics
Insulin-Like Growth Factor I metabolism
Interleukin-6 pharmacology
Interleukin-6 physiology
Liver drug effects
Male
RNA, Messenger metabolism
Rats
Rats, Sprague-Dawley
Receptors, Somatotropin genetics
Suppressor of Cytokine Signaling Proteins genetics
Suppressor of Cytokine Signaling Proteins metabolism
Tumor Necrosis Factor-alpha pharmacology
Tumor Necrosis Factor-alpha physiology
Growth Hormone metabolism
Lipopolysaccharides toxicity
Liver metabolism
Subjects
Details
- Language :
- Chinese
- ISSN :
- 0529-5815
- Volume :
- 40
- Issue :
- 12
- Database :
- MEDLINE
- Journal :
- Zhonghua wai ke za zhi [Chinese journal of surgery]
- Publication Type :
- Academic Journal
- Accession number :
- 12654216