title: Characteristics of A spermatogonia and preleptotene spermatocytes in the vitamin A-deficient rat testis.
abstract: The proliferative activity and other characteristics of germ cells in the vitamin A-deficient (VAD) rat testis were investigated. In the VAD testis, A spermatogonia and preleptotene spermatocytes were found. The A spermatogonia in the VAD testis showed a bromodeoxyuridine (BrdU) labeling index of 6.6 +/- 1.1% and a mitotic index of 2.8 +/- 0.5%. After continuous labeling with BrdU for up to four days, the ultimate labeling index of A spermatogonia was 11.6 +/- 2.5%, which is less than expected. It is concluded that in the VAD rat testis, many of the proliferating A spermatogonia degenerate. During the first 18 h after administration of vitamin A, no increase was observed in either the labeling index or the mitotic index of the A spermatogonia. However, after 24 h the first wave of A spermatogonia in S phase was found, and the first wave in mitosis was found after 48 h. Furthermore, in the VAD testis the DNA content of most of the A spermatogonia was similar to that of Sertoli cells, i.e., 2n. It is concluded that in the VAD situation, nearly all A spermatogonia are arrested before the S phase of the A1 spermatogonia. The hypothesis is put forward that in the VAD testis, the remaining A spermatogonia are the undifferentiated spermatogonia that are unable to differentiate into A1 spermatogonia. The preleptotene spermatocytes in the VAD testis showed a BrdU labeling index of 20.3 +/- 3.5%, while the DNA content of most of these cells was between 3n and 4n.(ABSTRACT TRUNCATED AT 250 WORDS)
authors.affiliation: Department of Cell Biology, Medical School, Utrecht University, The Netherlands.
authors.forename: A M
authors.initials: AM
authors.lastname: van Pelt
authors.forename: F M
authors.initials: FM
authors.lastname: van Dissel-Emiliani
authors.forename: I C
authors.initials: IC
authors.lastname: Gaemers
authors.forename: M J
authors.initials: MJ
authors.lastname: van der Burg
authors.forename: H J
authors.initials: HJ
authors.lastname: Tanke
authors.forename: D G
authors.initials: DG
authors.lastname: de Rooij
mesh_terms: D000818:Animals; D001973:Bromodeoxyuridine; D004247:DNA / Q000378:metabolism; D005260:Female; D007700:Kinetics; D008297:Male; D008938:Mitosis / Q000502:physiology; D008940:Mitotic Index; D051381:Rats; D017208:Rats, Wistar; D013090:Spermatocytes / Q000378:metabolism / Q000502:physiology*; D013093:Spermatogonia / Q000378:metabolism / Q000502:physiology*; D013737:Testis / Q000378:metabolism / Q000473:pathology*; D014802:Vitamin A Deficiency / Q000378:metabolism / Q000473:pathology*
chemical_list: D004247:DNA; D001973:Bromodeoxyuridine