title: Leydig cell number and function in the adult cynomolgus monkey (Macaca fascicularis) is increased by daily hCG treatment but not by daily FSH treatment.
abstract: Daily treatment of adult cynomolgus monkeys with 450 i.u. hCG for 16 days resulted in a significant 163% increase in the number of Leydig cells, and a 9-fold rise in plasma testosterone concentrations. The number of proliferating Leydig cells was very low, even after 16 days of treatment with hCG. Daily FSH administration (2 injections of 15 i.u. per day) did not have any effect on the number of Leydig cells or plasma testosterone values. It can be concluded, therefore, that in adult cynomolgus monkeys daily hCG treatment results in an increase in the number of Leydig cells, which is mainly caused by the differentiation of precursor cells. Since plasma testosterone concentrations were increased to an even higher extent, the steroid production per Leydig cell was also stimulated.
authors.affiliation: Department of Cell Biology, Medical School, State University of Utrecht, The Netherlands.
authors.forename: K J
authors.initials: KJ
authors.lastname: Teerds
authors.forename: F F
authors.initials: FF
authors.lastname: Rommerts
authors.forename: H J
authors.initials: HJ
authors.lastname: van de Kant
authors.forename: D G
authors.initials: DG
authors.lastname: de Rooij
mesh_terms: D000818:Animals; D002452:Cell Count; D006063:Chorionic Gonadotropin / Q000494:pharmacology*; D005640:Follicle Stimulating Hormone / Q000494:pharmacology*; D007985:Leydig Cells / Q000166:cytology / Q000187:drug effects / Q000502:physiology*; D008252:Macaca fascicularis; D008297:Male; D013739:Testosterone / Q000097:blood
chemical_list: D006063:Chorionic Gonadotropin; D013739:Testosterone; D005640:Follicle Stimulating Hormone