Restoration of ovarian steroid secretion and histologic assessment after freezing, thawing, and autograft of a hemi-ovary in sheep.

OBJECTIVE To evaluate the effects of freezing, thawing, and autograft of a hemi-ovary on steroid secretion, endometrial maturation, and ovarian histology in ewes. DESIGN Experimental animal study. SETTING Laboratoire de Zootechnie, Ecole Nationale Vétérinaire, Marcy l'Etoile, France. ANIMAL(S) Six lambs aged 6 months to 1 year old. INTERVENTION(S) Hemi-ovaries were prepared and frozen from the right ovary of six lambs and autografted 4 weeks later to the contralateral ovarian hilus. The autografts and the uterus were recovered 1 year later. Blood tests were performed each week to measure P concentration. MAIN OUTCOME MEASURE(S) Number of primordial follicles; levels of plasma P. RESULT(S) Histologic examination of ovarian slices after freezing showed no destruction of primordial, primary, secondary, or cavitary follicles. The frozen ovarian autograft showed good recovery of the macroscopic and microscopic ovarian structure. After autografting, histologic examination revealed primordial to cavitary follicles. Secretion of P started to rise 4 weeks after the autograft. Histologic analysis of the endometrium showed numerous glands, vessels, and mucous secretion. CONCLUSION(S) Frozen ovarian autografts achieved P secretion and endometrial maturity.