Premium
Insulin‐like growth factor 1, insulin, and progesterone induce early and late increases in Xenopus oocyte sn ‐1, 2‐diacylglycerol levels before meiotic cell division
Author(s) -
Stith Bradley J.,
Kirkwood Allan J.,
Wohnlich Erica
Publication year - 1991
Publication title -
journal of cellular physiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.529
H-Index - 174
eISSN - 1097-4652
pISSN - 0021-9541
DOI - 10.1002/jcp.1041490211
Subject(s) - diacylglycerol kinase , medicine , endocrinology , insulin , maturation promoting factor , hormone , biology , activator (genetics) , protein kinase c , xenopus , oocyte , insulin like growth factor , growth factor , kinase , microbiology and biotechnology , cell cycle , cell , biochemistry , receptor , cyclin dependent kinase 1 , embryo , gene
After a 3 to 6 hour incubation, addition of progesterone (the most effective), insulin‐like growth factor 1 (IGF‐1; the second most effective), or insulin induces meiotic cell division in Xenopus oocytes. Measurement of an endogenous activator of protein kinase C, sn‐1,2‐diacylglycerol (DAG), by an enzymatic method recording mass demonstrates that all three hormones alter DAG levels. Five seconds after addition, only progesterone transiently reduces DAG levels by about 25%. At 15 minutes after addition, all three hormones produce a peak of DAG (115% to 160% of control values), with the more effective hormones producing a larger increase in DAG. Insulin produces the smallest DAG increase, but the DAG release is longer lasting. Finally, all three hormones induce a second peak in DAG levels just before white spot appearance (at 0.85 GVBD 50 , where 1.0 GVBD 50 is when 50% of the cells have divided). With these data and since an activator of protein kinase C, a phorbol ester, has been found to induce meiosis, the kinase may play a role in early proliferative events at the plasma membrane and in late events at the nucleus.