ISSN:
0021-9541
Keywords:
Life and Medical Sciences
;
Cell & Developmental Biology
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Biology
,
Medicine
Notes:
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 GVBD50, where 1.0 GVBD50 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.
Additional Material:
5 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/jcp.1041490211
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