Testicular Function in Fructose-Induced Insulin-Resistant Rats.

LI MARQUES; CM MELLILLO; A RASHIA; B MAIZTEGUI; MO SUESCUN

Washington, DC

Congreso; 91st Annual Meeting ENDO 09; 2009

The Endocrine Society

P3-284] Testicular Function in Fructose-Induced Insulin-Resistant Rats. LI Marques, CM Mellillo, A Rashia, B Maiztegui, MO Suescun, Reproductive Endocrinology, IMBICE, CIC-CCT La Plata-CONICET, La Plata, Argentina; Chair of Endocrinology, Fac de Ciencias Exactas, UNLP, La Plata, Argentina; CENEXA, UNLP-CCT La Plata-CONICET, La Plata, Argentina Lately, there has been increasing evidence of the interaction between the metabolic syndrome (MS) and testicular function. Although the exact pathophysiological mechanisms remain unclear, some peripheral signals such as adipocyte- and stomach-derived Leptin and Ghrelin respectively, appear to play crucial roles in such interaction. A key factor contributing to the MS is insulin resistance (IR) and the subsequent insulin increase. The aim of the present study was to analyze IR effect on testicular steroidogenesis and the action of Leptin and Ghrelin as possible links between IR and testicular dysfunction. Fructose-rich diet (FRD) is a good experimental model of MS and IR. Normal male rats were fed with a standard commercial diet and water without (control, C ) or with 10% fructose (FRD) for three weeks. Blood glucose (strips), triglyceride (commercial kit) and insulin (radioimmunoassay) levels were measured at sacrifice. In vitro testosterone production by purified Leydig cells (LC) isolated from C and FRD rats was evaluated. The direct effect of Ghrelin (1nM) and Leptin (1nM) on testosterone production by LC incubated during 3 h under basal and hCG-stimulated conditions in FRD and C groups was also compared. Finally, mRNA Ghrelin receptor (GHS-r) expression (relative to -actin expression) by RT-PCR real time was evaluated in aliquots of testicular tissue and LC from FRD and C rats. FRD rats presented normoglycemia but impaired glucose tolerance, hypertriglyceridemia, hyperinsulinemia, and increased HOMA-IR index. Results showed that hCG (0.1-10 ng/mL) stimulated testosterone production was lower (30%) in purified LC from FRD than in C rats, p<0.05. We observed a similar inhibitory effect of Leptin on hCG-stimulated testosterone production by FRD and C purified LC (Leptin 1nM, hCG 1ng/mL, FRD: 49% vs C: 50%, NS). However Ghrelin inhibited differentially hCG-stimulated testosterone production in both groups (Ghrelin 1nM, hCG 1 ng/mL, FRD: 35% vs C: 23 %, p<0.05). Moreover, mRNA GHSr-1a expression showed a five fold increase in testicular tissue and LC from FRD respect to C rats, p<0.05. Our data show that in vitro steroidogenic activity by LC, direct Ghrelin effect on hCG-stimulated testosterone production by purified LC and mRNA GHSr-1a expression in testicular tissue are altered under insulin resistance conditions, which suggests a pivotal local role of Ghrelin in testicular dysfunction. Supported by A grant from Consejo Nacional de Investigaciones Cientificas y Tecnicas (CONICET), PIP 5331. by LC, direct Ghrelin effect on hCG-stimulated testosterone production by purified LC and mRNA GHSr-1a expression in testicular tissue are altered under insulin resistance conditions, which suggests a pivotal local role of Ghrelin in testicular dysfunction. Supported by A grant from Consejo Nacional de Investigaciones Cientificas y Tecnicas (CONICET), PIP 5331. by LC, direct Ghrelin effect on hCG-stimulated testosterone production by purified LC and mRNA GHSr-1a expression in testicular tissue are altered under insulin resistance conditions, which suggests a pivotal local role of Ghrelin in testicular dysfunction. Supported by A grant from Consejo Nacional de Investigaciones Cientificas y Tecnicas (CONICET), PIP 5331. by LC, direct Ghrelin effect on hCG-stimulated testosterone production by purified LC and mRNA GHSr-1a expression in testicular tissue are altered under insulin resistance conditions, which suggests a pivotal local role of Ghrelin in testicular dysfunction. Supported by A grant from Consejo Nacional de Investigaciones Cientificas y Tecnicas (CONICET), PIP 5331. by LC, direct Ghrelin effect on hCG-stimulated testosterone production by purified LC and mRNA GHSr-1a expression in testicular tissue are altered under insulin resistance conditions, which suggests a pivotal local role of Ghrelin in testicular dysfunction. Supported by A grant from Consejo Nacional de Investigaciones Cientificas y Tecnicas (CONICET), PIP 5331. by LC, direct Ghrelin effect on hCG-stimulated testosterone production by purified LC and mRNA GHSr-1a expression in testicular tissue are altered under insulin resistance conditions, which suggests a pivotal local role of Ghrelin in testicular dysfunction. Supported by A grant from Consejo Nacional de Investigaciones Cientificas y Tecnicas (CONICET), PIP 5331. in vitro steroidogenic activity by LC, direct Ghrelin effect on hCG-stimulated testosterone production by purified LC and mRNA GHSr-1a expression in testicular tissue are altered under insulin resistance conditions, which suggests a pivotal local role of Ghrelin in testicular dysfunction. Supported by A grant from Consejo Nacional de Investigaciones Cientificas y Tecnicas (CONICET), PIP 5331. Date: Friday, June 12, 2009Friday, June 12, 2009 Session Info: POSTER SESSION: BASIC/TRANSLATIONAL - Testicular Function & Androgen/Antiandrogen Action (1:30 PM-3:30 PM) Function & Androgen/Antiandrogen Action (1:30 PM-3:30 PM) Function & Androgen/Antiandrogen Action (1:30 PM-3:30 PM) Function & Androgen/Antiandrogen Action (1:30 PM-3:30 PM) Function & Androgen/Antiandrogen Action (1:30 PM-3:30 PM) Function & Androgen/Antiandrogen Action (1:30 PM-3:30 PM) POSTER SESSION: BASIC/TRANSLATIONAL - Testicular Function & Androgen/Antiandrogen Action (1:30 PM-3:30 PM) Presentation Time: 1:30 PM1:30 PM Room: Halls A & BHalls A & B