THE USE OF ENZYMATIC PROCEDURES TO RECOVER TESTICULAR GERM-CELLS

Intracytoplasmic sperm injection (ICSI) with testicular spermatozoa an d ejaculated spermatids has been applied successfully to treat inferti lity because of azoospermia due to obstruction or testicular failure, In most cases? free spermatozoa are recovered from testicular tissue a fter mechanical mincing of multiple biopsies, Testicular sperm retriev al, however, remains unsuccessful in a high proportion of male patient s suffering from testicular failure, In the present study, four media for enzymatic collagen digestion of testicular tissue were compared on 15 testis biopsies obtained from azoospermic patients following an IC SI treatment and on five biopsies from orchiectomy patients, To dissoc iate the testicular tissue, collagenase type IA, collagenase type IV, collagenase type IA supplemented with elastase and collagenase type IV supplemented with elastase were used, The preparations with only coll agenase type TV provided the best dissolution of the cells from their tissue, with a higher yield of free vital testicular spermatozoa and s ingle round germ cells, Enzymatic digestion of testicular tissue has t he advantage, especially in cases of testicular failure, that several biopsies can be concentrated into one pellet of single cells, In this way, the sperm retrieval in cases of testicular failure might be optim ized to yield the maximal numbers of spermatids and/or spermatozoa.