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Insulin-like growth factor-I reverts testicular atrophy in rats with advanced cirrhosis
I Castilla-Cortazar1, M Garcia, J Quiroga
1Department of Physiology, Liver Unit, University of Navarra, Pamplona, Spain. icastill@uma.es
Abstract:
The pathogenesis of hypogonadism in cirrhosis is not completely understood. The levels of insulin-like growth factor-I (IGF-I), an anabolic factor with trophic actions on testes, are reduced in cirrhosis. This study was undertaken to evaluate whether rats with advanced cirrhosis develop hypogonadism and whether the administration of IGF-I exerts beneficial effects on testicular structure and function. Wistar rats with ascitic cirrhosis induced with CCl(4) were allocated into 2 groups (n = 10, each) to receive recombinant IGF-I (20 microg x kg(-1) x d(-1), subcutaneously) or vehicle for 3 weeks. Healthy rats receiving vehicle were used as the control group (n = 10). At baseline, both cirrhotic groups showed similar deterioration of liver function tests. Compared with controls, nontreated cirrhotic rats showed decreased serum levels of IGF-I (P <.05), reduced testicular size and weight (P <.001), and intense histopathological testicular abnormalities, including reduced tubular diameters (P <.001), loss of the germinal line (P <. 001), and diminutions in cellular proliferation, spermatogenesis (P <.001), and testicular transferrin expression (P <.001). In addition, low serum testosterone (P <.01) and high serum LH (P <.01) were present in untreated cirrhotic animals. Cirrhotic rats that received IGF-I showed full recovery of testicular size and weight and of all histopathological abnormalities (P <.001 to <.01 vs. nontreated cirrhotic rats; P = ns vs. controls). Serum levels of sex hormones tended to normalize. In conclusion, IGF-I deficiency may play a pathogenetic role in hypogonadism of cirrhosis. Low doses of IGF-I for a short period of time revert testicular atrophy and appear to improve hypogonadism in advanced experimental cirrhosis.
Insights
Cirrhosis causes hypogonadism in rats, linked to low insulin-like growth factor-I (IGF-I). IGF-I treatment fully reversed testicular damage and improved function, suggesting IGF-I
Area of Science:
- Endocrinology
- Hepatology
- Reproductive Biology
Background:
- Hypogonadism is a common complication in cirrhosis, but its exact causes are not fully understood.
- Reduced levels of insulin-like growth factor-I (IGF-I), an important anabolic hormone for testicular function, are observed in cirrhotic patients.
- Cirrhosis can lead to significant testicular dysfunction and atrophy, impacting reproductive health.
Purpose of the Study:
- To investigate the development of hypogonadism in rats with advanced cirrhosis.
- To determine if IGF-I administration can ameliorate testicular structural and functional abnormalities in cirrhotic rats.
Main Methods:
- Wistar rats with carbon tetrachloride-induced cirrhosis were treated with either recombinant IGF-I or a vehicle for three weeks.
- A control group of healthy rats received vehicle treatment.
- Serum hormone levels, testicular size and weight, histopathological features, and molecular markers of testicular function were assessed.
Main Results:
- Nontreated cirrhotic rats exhibited decreased IGF-I, reduced testicular size and weight, and severe histopathological abnormalities, including impaired spermatogenesis and germinal cell loss.
- Cirrhotic rats treated with IGF-I showed complete recovery of testicular size and weight, along with normalization of histopathological findings.
- IGF-I treatment also led to a tendency towards normalization of serum testosterone and luteinizing hormone (LH) levels.
Conclusions:
- IGF-I deficiency plays a significant role in the pathogenesis of hypogonadism associated with advanced cirrhosis.
- Short-term administration of IGF-I effectively reverses testicular atrophy and improves hypogonadism in experimental cirrhosis.
- These findings highlight the therapeutic potential of IGF-I for managing hypogonadism in liver cirrhosis.