The role of protein kinase A and cyclin-dependent (CDC2) kinase in the control of basal and IGF-II-induced proliferation and secretory activity of chicken ovarian cells.
The aim of these experiments was to study the role of protein kinase A (PKA), cyclin-dependent kinase 2 (CDC2) and insulin-like growth factor II (IGF-II) in the control of ovarian function in domestic fowl, as well as the role of PKA and CDC2 in mediating the effects of IGF-II on the ovary. For this purpose, we studied the influence of an inhibitor of PKA (KT5720; 50 ng/ml), a CDC2 blocker (olomoucine; 1 microg/ml), IGF-II (0, 1, 10 or 100 ng/ml) and their combinations on cultured fragments of chicken ovarian follicular wall. Accumulation of PKA and CDC2 and secretion of progesterone (P4), testosterone (T), estradiol (E2) and arginine-vasotocin (AVT) were evaluated by using SDS-PAGE-Western blotting and RIA/EIA. IGF-II addition to culture medium stimulated T, E2 and AVT secretion and inhibited P4 secretion. These changes were associated with an increase in PKA and a decrease in CDC2 accumulation. The PKA blocker KT5720, when given alone, increased accumulation of PKA and secretion of T and E2, but not AVT and inhibited P4 secretion. The PKA blocker also prevented and even reversed the effects of IGF-II on PKA and steroid hormones secretion, but enhanced the action of IGF-II on AVT. The inhibitor of CDC2, olomoucine, when given alone, suppressed the expression of CDC2 and the secretion of P4 and AVT (but not T and E2). When given together with IGF-II, it augmented IGF-II-induced suppression of CDC2 and reversed the effects of IGF-II on P4 (but not on T, E2 or AVT). These observations demonstrate the involvement of PKA, CDC2 and IGF-II in regulating the secretory activity of avian ovarian cells. Our data also suggest the involvement of PKA in the mediation of IGF-II effects on P4, T, E2 and AVT secretion. CDC2 can mediate the effects of IGF-II on ovarian P4 secretion but not on other hormones.
Sirotkin
A V
AV
Research Institute of Animal Production, Hlohovská 2, 949 92 Nitra, Slovakia. sirotkin@vuzv.sk
Grossmann
R
R
D000818:Animals; D002227:Carbazoles / Q000494:pharmacology; D048708:Cell Growth Processes / Q000187:drug effects / Q000502:physiology; D017868:Cyclic AMP-Dependent Protein Kinases / Q000037:antagonists & inhibitors / Q000378:metabolism / Q000502:physiology*; D051357:Cyclin-Dependent Kinase 2 / Q000037:antagonists & inhibitors / Q000378:metabolism / Q000502:physiology*; D004958:Estradiol / Q000378:metabolism; D005260:Female; D006107:Granulosa Cells / Q000166:cytology / Q000201:enzymology / Q000378:metabolism / Q000502:physiology*; D007211:Indoles / Q000494:pharmacology; D007335:Insulin-Like Growth Factor II / Q000494:pharmacology* / Q000502:physiology; D007701:Kinetin / Q000494:pharmacology; D006080:Ovarian Follicle / Q000166:cytology / Q000201:enzymology / Q000378:metabolism / Q000502:physiology*; D011374:Progesterone / Q000378:metabolism; D047428:Protein Kinase Inhibitors / Q000494:pharmacology; D011758:Pyrroles / Q000494:pharmacology; D013739:Testosterone / Q000378:metabolism; D013799:Theca Cells / Q000201:enzymology / Q000378:metabolism / Q000502:physiology; D014668:Vasotocin / Q000378:metabolism
D002227:Carbazoles; D007211:Indoles; D047428:Protein Kinase Inhibitors; D011758:Pyrroles; D013739:Testosterone; D011374:Progesterone; D004958:Estradiol; C057416:KT 5720; D007335:Insulin-Like Growth Factor II; C090046:olomoucine; D017868:Cyclic AMP-Dependent Protein Kinases; D051357:Cyclin-Dependent Kinase 2; D007701:Kinetin; D014668:Vasotocin