TY - JOUR
T1 - Deoxyribonucleic acid polymerase-α activity in hamster follicles during the estrous cycle
T2 - roles of follicle stimulating hormone and luteinizing hormone
AU - Roy, Shyamal K.
AU - Greenwald, Gilbert S.
N1 - Funding Information:
was supported by a grant from NIH
PY - 1989/2
Y1 - 1989/2
N2 - In the hamster, DNA polymerase-a (Pol-α) in follicles at stages 1-4 (1-4 layers granulosa cells and no theca) increased significantly during the proestrous (P) gonadotropin surges, remained high on estrus (E) and then declined to low levels by 09.00 h, proestrus (P). However, Pol-a in stages 5-8 (large preantral to small antral stages) remained steady throughout the cycle. Hypophysectomy on metestrus decreased Pol-a by 17 h which was reversed by 2.5 μg follicle stimulating hormone (FSH) but not by luteinizing hormone (LH) (2.5 jug) or human chorionic gonadotropin (hCG) (1 IU). Hypophysectomy on E resulted 72 h later in a fall in Pol-α in stages 1-6; FSH (2.5 fig) or LH (2 μg) restored enzyme activity within 5 h to stages 1-6 and 5-6, respectively. Thus, Pol-α in the smallest preantral follicles is induced by FSH; however, for large preantral and antral follicles, steady levels are maintained by tonic FSH and LH resulting in no apparent change in enzyme activity during active DNA synthesis.
AB - In the hamster, DNA polymerase-a (Pol-α) in follicles at stages 1-4 (1-4 layers granulosa cells and no theca) increased significantly during the proestrous (P) gonadotropin surges, remained high on estrus (E) and then declined to low levels by 09.00 h, proestrus (P). However, Pol-a in stages 5-8 (large preantral to small antral stages) remained steady throughout the cycle. Hypophysectomy on metestrus decreased Pol-a by 17 h which was reversed by 2.5 μg follicle stimulating hormone (FSH) but not by luteinizing hormone (LH) (2.5 jug) or human chorionic gonadotropin (hCG) (1 IU). Hypophysectomy on E resulted 72 h later in a fall in Pol-α in stages 1-6; FSH (2.5 fig) or LH (2 μg) restored enzyme activity within 5 h to stages 1-6 and 5-6, respectively. Thus, Pol-α in the smallest preantral follicles is induced by FSH; however, for large preantral and antral follicles, steady levels are maintained by tonic FSH and LH resulting in no apparent change in enzyme activity during active DNA synthesis.
KW - (Hamster)
KW - Gonadotropin
KW - Polymerase-α
KW - Preantral follicle
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U2 - 10.1016/0303-7207(89)90126-3
DO - 10.1016/0303-7207(89)90126-3
M3 - Article
C2 - 2492957
AN - SCOPUS:0024532623
SN - 0303-7207
VL - 61
SP - 157
EP - 166
JO - Molecular and Cellular Endocrinology
JF - Molecular and Cellular Endocrinology
IS - 2
ER -