Questions on Malcolm's MMP update.

The proposed role for MMPs (and TIMPs) in luteolysis (i.e. that lack of
gonadotrophin results in loss of cell matrix and cell death) seems to
suppose that gonadotrophin-induced changes in the cell matrix precede
changes in luteal cell function.

Is anything known about steroid regulation of MMPs or TIMPs?

Could it be that luteolysis is induced by some other mechanism (dare I say
prostaglandins?) and that the decrease in progesterone synthesis leads to
degradation of the ECM with functional luteolysis secondary to a compromise
of luteal cell function?

How are the direct effects of hCG on ECM stability discriminated from
effects mediated by progesterone?

Have recently become aware of the fact that progesterone regulates gap
junction formation (at least in the placenta) and I wonder whether effects
of progesterone on these junctions may be complemented by any
steroid-induced changes in the matrix surrounding adjacent cells.


Tony Michael

Dr.Tony Michael
Lecturer in Biochemistry & Molecular Biology,
Dept.Biochemistry & Molecular Biology,                                Tel :
0171-794-0500 x.4999 (Office)
Royal Free Hospital School of Medicine,                                 Tel
: 0171-794-0500 x.4988 (Lab)
Rowland Hill Street,
Fax : 0171-794-9645
London NW3 2PF