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Lardone M.C.,University of Chile | Castillo P.,University of Chile | Valdevenito R.,University of Chile | Ebensperger M.,San Borja Arriaran Clinical Hospital | And 4 more authors.
International Journal of Andrology | Year: 2010

There is evidence that impaired spermatogenesis is associated with an imbalance in the oestradiol/testosterone ratio and with Leydig cell (LC) dysfunction. In testis, P450-aromatase, encoded by CYP19, is responsible for the conversion of testosterone to oestradiol. The aims of this study were to quantify CYP19 mRNA expression, aromatase activity and protein localization, and to measure the oestradiol to testosterone ratio in testicular tissues of men with spermatogenic impairment. Twenty-four men with complete Sertoli cell-only syndrome (SCOS), 14 with focal SCOS, 14 with maturation arrest (MA), 8 with mixed atrophy and 30 controls with normal spermatogenesis were subjected to testicular biopsy. All subjects underwent a physical examination, cytogenetic and serum hormonal studies. Testicular CYP19 mRNA was quantified using real time RT-PCR. Testicular aromatase activity was measured using the 3H 20 assay and protein expression was evaluated using immunohistochemistry. In cases, serum testosterone and oestradiol were normal, but the testosterone/LH ratio was lower compared with controls (p < 0.05). Aromatase was localized in the Leydig, Sertoli and germ cells of all tissues, although stronger intensity was observed in LC. Aromatase mRNA and activity were not altered in cases and correlated positively with LC number (r = 0.516 and r = 0.369; p < 0.008). The intratesticular oestradiol/testosterone ratio was elevated (p = 0.005) in complete SCOS patients compared with controls. In conclusion, testicular aromatase seems to be normal in most subjects with impaired spermatogenesis. However, an altered intratesticular oestradiol/testosterone ratio in some patients with complete SCOS suggests that aromatase is increased, which might contribute to Leydig cell dysfunction. © 2010 European Academy of Andrology. Source

Lardone M.C.,University of Chile | Piottante A.,Andres Bello University | Valdevenito R.,University of Chile | Ebensperger M.,San Borja Arriaran Clinical Hospital | Castro A.,University of Chile
Andrologia | Year: 2013

We characterised and correlated the histological and hormonal aspects of a cohort of 261 azo/oligozoospermic men, applying a quantitative/qualitative evaluation of testicular tissue and serum and intratesticular hormonal measurements. One hundred and 93 azo/oligozoospermic patients were diagnosed as: complete sertoli cell only syndrome (cSCOS), n = 76; focal SCOS, n = 31; maturation arrest, n = 34; hypospermatogenesis, n = 17; mixed atrophy, n = 25; and severe atrophy, n = 10. Normal spermatogenesis was observed in 68 infertile men (controls). Patients with cSCOS, focal SCOS, mixed and severe atrophy had larger LC/clusters (11.5; 11.0; 10.7; 18.9 LC/cluster) than controls (6 LC/cluster; P < 0.001). cSCOS, focal SCOS, mixed and severe atrophy patients had higher FSH, LH and lower T/LH ratio serum levels than the other groups. Intratesticular testosterone concentrations were higher in tissues with complete or focal SCOS (45.6 ng mg-1 protein) and mixed atrophy (79.0 ng mg-1 protein) than normal tissues (20.3 ng mg-1 protein; P = 0.03 and P = 0.007). Considering all subjects, significant correlations were found between T/LH ratio and Leydig cells/cluster (r = 0.510, P < 0.001), FSH levels (r = -0.692, P < 0.001) and with intratesticular testosterone (r = -0.354, P = 0.001); these correlations follow the pattern of severity of spermatogenic damage. By a thorough histological evaluation, we validate the concept that the severity of spermatogenic impairment is associated with major morphological and functional disturbance of the Leydig cell compartment. © 2012 Blackwell Verlag GmbH. Source

Amory J.K.,University of Washington | Arnold S.,University of Washington | Lardone M.C.,University of Chile | Piottante A.,Andres Bello University | And 5 more authors.
Fertility and Sterility | Year: 2014

Objective To determine whether decreased testicular levels of enzymes necessary for retinoic acid biosynthesis were associated with male infertility, as retinoic acid is known to be necessary for spermatogenesis. Design Observational analysis of testicular tissue samples, sperm indices, and serum hormone concentrations. Setting Two infertility centers in Chile. Patient(s) 32 infertile men and 11 control men. Intervention(s) Measurement of the three enzymes necessary for retinoic acid biosynthesis, aldehyde dehydrogenase (ALDH) 1A1, 1A2, and 1A3, in testicular tissue by a novel liquid chromatography coupled with tandem mass spectrometry (LC-MS/MS) peptide assay. Main Outcome Measure(s) ALDH isozyme levels compared by type of infertility and correlated with testicular germ cell numbers, sperm parameters, and serum and intratesticular hormone concentrations. Result(s) Men with infertility had statistically significantly reduced levels of ALDH1A2 but not ALDH1A1 or ALDH1A3 in their testicular tissue compared with men with normal spermatogenesis. The ALDH1A2 protein levels were strongly correlated with the number of germ cells found via testicular biopsy. Conclusion(s) These findings suggest that ALDH1A2 is the enzyme involved in retinoic acid biosynthesis in human germ cells. Further study of the relationship between intratesticular ALDH1A2 and male infertility is warranted to determine whether men with infertility have a reduced ability to synthesize retinoic acid within their germ cells that could impair spermatogenesis. © 2014 American Society for Reproductive Medicine, Published by Elsevier Inc. All rights reserved. Source

Lardone M.C.,University of Chile | Marengo A.,University of Chile | Parada-Bustamante A.,University of Chile | Cifuentes L.,University of Chile | And 4 more authors.
Journal of Assisted Reproduction and Genetics | Year: 2013

Purpose: To determine the prevalence of South Amerindian Y chromosome in Chilean patients with spermatogenic failure and their association with classical and/or AZFc-partial Y chromosome deletions. Methods: We studied 400 men, 218 with secretory azo/oligozoospermia (cases) and 182 controls (116 fertile and/or normozoospermic, and 66 azoospermic with normal spermatogenesis). After a complete testicular characterization (physical evaluation, hormonal and/or biopsy) peripheral blood was drawn to obtain DNA for Y chromosome microdeletions, AZFc-partial deletions and biallelic analysis by allele specific polymerase chain reaction (PCR) of the M3 (rs3894) single nucleotide polymorphism (SNP). Results: Classical AZF microdeletions were found in 23 cases (Y-microdeleted). AZFc-partial deletions were observed in 10 cases (6 "gr/gr", 3 "b2/b3" and 1 "b1/b3") and 4 controls (4 "gr/gr"). The AZFc-partial deletions were mainly associated with the absence of DAZ1/DAZ2 (64 %). No significant differences in the prevalence of AZFc-partial deletions were observed between cases and controls. We observed a significant higher proportion of the Q1a3a haplogroup in Y-microdeleted men compared to patients with spermatogenic failure without deletions and control men (P < 0.01 and P < 0.05, respectively by Bonferroni test). Among them, patients with AZFb deletions had an increased prevalence of the Q1a3a haplogroup compared to controls, cases without deletions and to those with complete or partial-AZFc deletions (P < 0.01, Bonferroni test). Conclusions: The Q1a3a South Amerindian lineage seems to increase the susceptibility to non AZFc microdeletions. On the other hand, in Chilean population the AZFc-partial deletions ("gr/gr", "b1/b3" and/or "b2/b3") does not seem to predispose to severe spermatogenic impairment. © 2013 Springer Science+Business Media New York. Source

Castro-Nallar E.,University of Chile | Bacallao K.,University of Chile | Parada-Bustamante A.,University of Chile | Lardone M.C.,University of Chile | And 6 more authors.
Journal of Andrology | Year: 2010

There is ample documentation supporting the fact that androgens are required for normal spermatogenesis. A minority of infertile men have abnormal testosterone blood levels or mild androgen receptor mutations. We investigated the androgen receptor CAG and GGN repeat lengths in Chilean men with spermatogenic impairment. We studied 117 secretory azoospermic/oligozoospermic men (93 idiopathic and 24 excryptorchidic), without Y-chromosome microdeletions, and 121 controls with normal spermatogenesis (42 obstructive and 79 normozoospermic men). Peripheral blood was drawn to obtain genomic DNA for polymerase chain reaction and automated sequencing of CAG and GGN repeats. Testicular characterization included hormonal studies, physical evaluation, and seminal and biopsy analysis. The CAG and GGN polymorphism distributions were similar among idiopathic men, excryptorchidic men, and controls and among the different types of spermatogenic impairment. However, the proportion of the CAG 21 allele was significantly increased in idiopathic cases compared to controls (P = .012 by Bonferroni test, odds ratio = 2.99, 95% confidence interval, 1.27-7.0) and the CAG 32 allele only was observed in excryptorchidic patients (P < .0002, Bonferroni test). Idiopathic cases with Sertoli cell-only syndrome showed the highest proportion of the CAG 21 allele (P = .024, χ 2 test). On the other hand, in idiopathic cases and controls the most common GGN allele was 23, followed by 24, but an inverse relation was found among excryptorchidic cases. The joint distribution of CAG and GGN in control, idiopathic, and excryptorchidic groups did not show an association between the 2 allele repeat polymorphisms (P > 0.05, χ 2 test). Our results suggest that the CAG 21 allele seems to increase the risk of idiopathic Sertoli cell-only syndrome. Moreover, the GGN 24 allele could be contributing to deranged androgen receptor function, associated with cryptorchidism and spermatogenic failure. Copyright © American Society of Andrology. Source

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