title: Enhanced expression of tyrosine kinase receptor a in germ cells of rat testis with acute experimental testicular torsion.
abstract: OBJECTIVE
  To examine the involvement of neurotrophic factor receptors in the testis with acute experimental testicular torsion, the expression of tyrosine kinase receptors (trk) A and B, and p75 nerve growth factor receptor (NGFR) were studied in the rat testis with ischemia/reperfusion (I/R) injury, using Western blotting and immunohistochemistry. Apoptosis was detected using the terminal deoxynucleotidyl transferase-mediated dUTP nick end-labeling (TUNEL) method.
  
  
  RESULTS
  There was a significant increase in TUNEL-positive reaction in spermatogonia in the seminiferous tubules in rat testes after testicular torsion. Western blot analysis showed that trk A expression reached a significant peak at 12 h after reperfusion (p < 0.01), as compared to sham-operated controls, whereas trk B was not increased in the testis after I/R. Constitutive expression of p75 NGFR was at or below the level detectable by Western blot analysis, and it remained unchanged in the testis after I/R. Immunohistochemistry demonstrated that after I/R trk A expression was increased in spermatocytes and spermatids in the seminiferous tubules, in contrast to the basal location of the TUNEL-positive reaction. Immunoreactivity of trk B was seen mainly in the interstitial cells in the sham-operated testis, and its localization was not changed after I/R.
  
  
  CONCLUSIONS
  It is postulated that trk A and B, but not p75 NGFR, are involved differently in the survival of testicular cells during acute experimental testicular torsion. In particular, increased trk A seems to be related to germ cell survival following I/R.
authors.affiliation: Department of Veterinary Medicine, Cheju National University, Jeju, South Korea. cmoon@cheju.ac.kr
authors.forename: Changjong
authors.initials: C
authors.lastname: Moon
authors.forename: Fumioki
authors.initials: F
authors.lastname: Yasuzumi
authors.forename: Nobuhiko
authors.initials: N
authors.lastname: Okura
authors.forename: Heechul
authors.initials: H
authors.lastname: Kim
authors.forename: Meejung
authors.initials: M
authors.lastname: Ahn
authors.forename: Taekyun
authors.initials: T
authors.lastname: Shin
mesh_terms: D000818:Animals; D005854:Germ Cells / Q000378:metabolism*; D008297:Male; D051381:Rats; D017207:Rats, Sprague-Dawley; D020917:Receptor, trkA / Q000096:biosynthesis*; D013086:Spermatic Cord Torsion / Q000378:metabolism* / Q000473:pathology
chemical_list: D020917:Receptor, trkA