The concentration of ouabain binding sites in biopsies of uterine muscle
Research output: Contribution to journal › Journal article › Research › peer-review
The concentration of Na,K-ATPase in biopsies of uterine muscle was determined by measurement of [3H]ouabain binding in the presence or vanadate. For this purpose a method previously described for skeletal muscle (Norgaard et al. 1983) was modified. Biopsies were obtained from uterine muscle from pregnant women (during caesarian section), non-pregnant women (during hysterectomy) and from adult, non-pregnant guinea-pigs and rats. The ouabain binding site concentration in uterine muscle of the pregnant women averaged 72 ± 2 pmol g-1 wet wt (n = 8), with an apparent dissociation constant (K(D)) for ouabain of 3 x 10-9 mol l-1. The ouabain-binding capacity in uterine muscle of the non-pregnant women amounted to 83 ± 9 pmol g-1 wet wt (n = 8). In uterine muscle of the guinea-pig, two populations of ouabain binding sites were observed: one with a maximum binding capacity of 230 pmol g-1 wet wt and an apparent K(D) of 1.6 x 10-6 mol l-1, and one with a maximum capacity of 62 pmol g-1 wet wt and an apparent K(D) of 5 x 10-8 mol l-1. Immediate freezing of the biopsies in liquid N2 and storage at -60°C for up to 6 weeks caused no change in ouabain-binding capacity. The dry weight/wet weight ratio of the samples from different subjects showed values of around 20%. It is concluded that the concentration of Na-K pumps in human uterine muscle can be quantified by [3H]ouabain binding using samples weighing 5-10 mg. The method may provide a useful approach in clinical studies, i.e. analysis of the changes in Na, K-ATPase concentration that may occur as a basis for disturbances of labour.
Original language | English |
---|---|
Journal | Acta Physiologica Scandinavica |
Volume | 139 |
Issue number | 3 |
Pages (from-to) | 503-510 |
Number of pages | 8 |
ISSN | 0001-6772 |
DOIs | |
Publication status | Published - 1 Jan 1990 |
Externally published | Yes |
- guinea-pig, human, Na,K-ATPase, pregnancy, rat, uterine muscle, [H]ouabain
Research areas
ID: 218255805