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Aquaporin‐9 immunohistochemistry in varicocele testes as a consequence of hypoxia in the sperm production site
Author(s) -
Arena S.,
Arena F.,
Maisano D.,
Di Benedetto V.,
Romeo C.,
Nicòtina P. A.
Publication year - 2011
Publication title -
andrologia
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.633
H-Index - 59
eISSN - 1439-0272
pISSN - 0303-4569
DOI - 10.1111/j.1439-0272.2009.01009.x
Subject(s) - sertoli cell , spermatogenesis , epididymis , varicocele , andrology , spermiogenesis , biology , immunostaining , immunohistochemistry , testicle , endocrinology , sperm , medicine , pathology , infertility , pregnancy , genetics
Summary Aquaporin‐9 (AQP‐9) regulates tissue hydration by promoting transmembrane exchanges of both water and solutes, such as lactate. The latter is a key metabolite of primary spermatocytes and of maturing haploid germ cells (h‐GCs). The present investigation was aimed at immunolocalising human AQP‐9 in both normal and varicocele testes. Histology and immmunocytochemistry were investigated in archival biopsies from 20 varicocele testes and in eight unaffected ones. AQP‐9 immunostaining was performed using a rabbit antibody, and either focal or diffuse cell membrane labelling was recorded. Varicocele testes showed disarranged tubular compartments, with sloughing h‐GCs, tissue hyperhydration, spermiogenesis failure and fibrosis. AQP‐9 immunohistology of the control testes showed a diffuse cell membrane staining of the primary spermatocytes and h‐GCs, without any positive reaction of spermatogonia and Sertoli cells. AQP‐9 cell expression in the varicocele testes was focal or lacking in both adluminal and sloughing GCs. AQP‐9 expression occurs in normal human testis, at cell membrane of primary spermatocytes and h‐GCs, suggesting a possible role of AQP‐9 in the water and lactate transport from Sertoli cells to GCs. AQP‐9 is focal or lacking in adolescent varicocele testes, and this suggests AQP‐9 to be downregulated in such testicular disorder, leading to lactate deprivation with subsequent hypospermatogenesis.