Changes in transport functions of isolated rabbit choroid plexus under the influence of oestrogen and progesterone

Abstract

Isolated choroid plexuses from rabbits were used to determine uptake and accumulation of 10(-5) M radiolabelled choline (expressed as tissue/medium ratio) and the activities of various types of ATPases (based on ouabain inhibition and bicarbonate stimulation) following pre-treatment of the animals with 0.5 mg kg-1 17-beta-oestradiol, alone or in combination with 2 mg kg-1 progesterone. The combined treatment reduced the choline uptake by 35% and also lowered the activity of Na+,K+-ATPase by 31%, without influencing tissue wet weight. The reduction in HCO3-ATPase was smaller and not statistically significant. There was a tendency also for oestrogen alone to lower these activities, but only by less than 20%. The Ca2+,Mg2+-ATPase activity was not significantly affected by any of the hormones.