Little effects of insulin-like Growth Factor-I on testicular atrophy induced by hypoxia

• Published in: BMC urology Vol. 6; no. 1; p. 4
• Main Authors: Diez-Caballero, Fernando, Castilla-Cortázar, Inma, Garcia-Fernandez, Maria, Puche, Juan Enrique, Diaz-Sanchez, Matias, Casares, Amelia Diaz, Aliaga-Montilla, M Aurelia, Rodriguez-Borrajo, Coronación, Gonzalez-Barón, Salvador
• Format: Journal Article
• Language: English
• Published: England BioMed Central Ltd 21.02.2006; BioMed Central; BMC
• Subjects: Animals; Atrophy; Cell Proliferation; Glutathione Peroxidase - metabolism; Hypoxia - pathology; Immunohistochemistry; Insulin-Like Growth Factor Binding Proteins - blood; Insulin-Like Growth Factor I - analysis; Insulin-Like Growth Factor I - pharmacology; Ischemia - metabolism; Ischemia - pathology; Male; Phospholipid Hydroperoxide Glutathione Peroxidase; Proliferating Cell Nuclear Antigen - analysis; Rats; Rats, Wistar; Seminiferous Tubules - pathology; Testis - drug effects; Testis - metabolism; Testis - pathology; Transferrin - analysis
• ISSN: 1471-2490; 1471-2490
• DOI: 10.1186/1471-2490-6-4

Insulin-like Growth Factor-I (IGF-I) supplementation restores testicular atrophy associated with advanced liver cirrhosis that is a condition of IGF-I deficiency. The aim of this work was to evaluate the effect of IGF-I in rats with ischemia-induced testicular atrophy (AT) without liver disease and consequently with normal serum level of IGF-I. Testicular atrophy was induced by epinephrine (1, 2 mg/Kg intra-scrotal injection five times per week) during 11 weeks. Then, rats with testicular atrophy (AT) were divided into two groups (n = 10 each): untreated rats (AT) receiving saline sc, and AT+IGF, which were treated with IGF-I (2 microg.100 g b.w.(-1).day(-1), sc.) for 28 d. Healthy controls (CO, n = 10) were studied in parallel. Animals were sacrificed on day 29th. Hypophyso-gonadal axis, IGF-I and IGFBPs levels, testicular morphometry and histopathology, immuno-histochemical studies and antioxidant enzyme activity phospholipid hydroperoxide glutathione peroxidase (PHGPx) were assessed. Compared to controls, AT rats displayed a reduction in testicular size and weight, with histological testicular atrophy, decreased cellular proliferation and transferrin expression, and all of these alterations were slightly improved by IGF-I at low doses. IGF-I therapy increased significantly steroidogenesis and PHGPx activity (p < 0.05). Interestingly, plasma IGF-I did not augment in rats with testicular atrophy treated with IGF-I, while IGFBP3 levels, that reduces IGF-I availability, was increased in this group (p < 0.05). In testicular atrophy by hypoxia, condition without IGF-I deficiency, IGF-treatment induces only partial effects. These findings suggest that IGF-I therapy appears as an appropriate treatment in hypogonadism only when this is associated to conditions of IGF-I deficiency (such as Laron Syndrome or liver cirrhosis).