title: FSH prevents depletion of the resting follicle pool by promoting follicular number and morphology in fresh and cryopreserved primate ovarian tissues following xenografting.
abstract: BACKGROUND
  Cryopreservation and transplantation of ovarian tissue is one option for re-establishing ovarian function, but optimal conditions for graft sustainment and follicular survival are still considered experimental. The present study aims to analyze the effect of FSH treatment on the resting follicle pool in fresh and cryopreserved primate ovarian tissues following xenografting.
  
  
  METHODS
  Ovarian tissues from adult marmosets were grafted freshly or following cryopreservation to ovarectomized nude mice treated with FSH 25 IU twice daily post transplantation or left untreated as controls. Grafts were retrieved 2 or 4 weeks after transplantation to evaluate the number and morphological appearance of follicles.
  
  
  RESULTS
  Early start of FSH treatment within 1 week following transplantation partly prevents primordial follicle loss in fresh and frozen-thawed tissues, whereas after a 3 weeks time interval this effect is present only in fresh tissues. A similar positive effect of early, but not later FSH treatment on primary follicles is seen in fresh tissues compared to only marginal effects in frozen-thawed tissues. The percentage of morphologically normal follicles is generally increased in FSH treated tissues, whereas the percentage of primary follicles over all primordial and primary follicles is increased by FSH only in freshly-grafted tissues.
  
  
  CONCLUSIONS
  FSH treatment alleviates depletion of the resting follicle pool and promotes normal follicular morphology both in freshly and frozen-thawed grafted tissues. In previously cryopreserved tissues, applying to most of the tissues intended for clinical use in fertility preservation attempts, its positive effect on primordial follicle numbers and potential graft sustainment is dependent on an early start of treatment within one week of transplantation.
authors.affiliation: Department of Gynecology and Obstetrics, Campus Grosshadern Ludwig-Maximilians-University Munich, Munich, Germany.
authors.forename: Viktoria
authors.initials: V
authors.lastname: von Schönfeldt
authors.forename: Ramesh
authors.initials: R
authors.lastname: Chandolia
authors.forename: Robert
authors.initials: R
authors.lastname: Ochsenkühn
authors.forename: Eberhard
authors.initials: E
authors.lastname: Nieschlag
authors.forename: Ludwig
authors.initials: L
authors.lastname: Kiesel
authors.forename: Barbara
authors.initials: B
authors.lastname: Sonntag
mesh_terms: D000818:Animals; D002144:Callithrix; D015925:Cryopreservation / Q000662:veterinary; D005260:Female; D059247:Fertility Preservation; D005640:Follicle Stimulating Hormone / Q000494:pharmacology*; D051379:Mice; D008819:Mice, Nude; D023421:Models, Animal; D006080:Ovarian Follicle / Q000033:anatomy & histology / Q000187:drug effects* / Q000502:physiology*; D010053:Ovary / Q000033:anatomy & histology / Q000502:physiology / Q000637:transplantation*; D014183:Transplantation, Heterologous
chemical_list: D005640:Follicle Stimulating Hormone