Biochemical characterization of the Arctic char (Salvelinus alpinus) ovarian progestin membrane receptor

Table 1 EC 50 and relative binding affinity (RBA) of various steroids and xenobiotics for Arctic char ovarian membrane fractions.

Competitor	Concentration (nM) causing 50% displacement	RBA (%)
17,20β-P	1.25	100.0
E2	37.9	4.68
P4	52.6	3.37
17α-OH-P	69.3	2.56
11-DOC	132.3	1.34
20β-S	145.2	1.22
DC	207.1	0.86
Flutamide	256.1	0.49
o,p'-DDT	377.5	0.37
o,p'-DDD	549.2	0.30
ZK 112992	1179	0.11
ZK 98299	12879.8	0.01
F	14421.2	0.01
T	18347.21	0.01
11-KT	ND	0.0
P5	ND	0.0
Kepone	ND	0.0
Nonylphenol	ND	0.0
o,p'-DDE	ND	0.0
Cimetidine	ND	0.0
ORG 31710	ND	0.0

ND indicates substances that did not display 50% displacement of 17,20β-P from its receptor in the range of concentrations examined (steroids: 0.1 nM – 10μM, RBA < 0.01%; xenobiotics, hormone antagonists: 0.1 nM – 1 mM, RBA < 0.0001%).

ISSN: 1477-7827