Table 4.

Summary of BKβ and BKα surface densities and BKα clustering

	LTH		NX
	Adult	Fetus	Adult	Fetus
Flow cytometry
Geometric mean, FL	299 ± 17*	546 ± 68	452 ± 27	206 ± 13*
Mean cell count/sample	1.2 × 104	3 × 104	3 × 104	6.5 × 105
Relative surface area, pFa	16.1 ± 1.3	9.4 ± 1.7	15.7 ± 0.6	9.1 ± 0.6
BKβ1 surface density, FL/pF	18.6	58.1	28.8	22.6
Channels per micropatch
Mean BK channel per patch	2.1 ± 0.2	2.6 ± 0.3	2.2 ± 0.2	2.6 ± 0.2
Mean tip resistance, MΩ	15.2 ± 0.1	15.9 ± 0.1	15.3 ± 0.1	15.5 ± 0.1
BK per patch, minus empties	2.3 ± 0.2*	3.7 ± 0.3	2.5 ± 0.2	2.6 ± 0.2*
%Patches with no BK channels	8.3	31.7	7.0	1.6
%Patches with 1 BK channel	27.8	7.1	27.9	29.0
%BK channels clusteredb	33.3	50.0	37.2	53.2
BK clustering
Total BKα, (103)c	9.2 ± 1.1	6.0 ± 1.1	9.8 ± 1.3	5.8 ± 1.1
BKα surface density, (102)d	8.0 ± 1.2	6.6 ± 1.0	7.6 ± 1.0	6.8 ± 0.9
BKα clusters/total BKα, (10−3)e	1.4 ± 0.2*	3.8 ± 0.4	1.4 ± 0.2*	3.4 ± 0.2
Cluster colocalization
Number of BKα clusters (103)f	11.6 ± 2.8	20.0 ± 0.4	12.5 ± 4.3	15.6 ± 4.8
Number of cholera toxin clusters (102)g	7.5 ± 0.9	9.2 ± 1.9	5.8 ± 1.7	10.0 ± 2.1
Colocalized clusters (103)h	2.6 ± 1.2*	7.8 ± 1.6	2.8 ± 0.8*	9.0 ± 1.6
%BKα clusters colocalized	31.9	39.0	32.0	53.8

Values are means ± SE, as appropriate, with n values indicated in accompanying text or figures. Flow cytometry was used to measure BK β₁ surface expression (Fig. 5) and calculate relative β₁ surface density. Channels per micropatch are estimated BK channels on excised micro-patches.

^aMeasured in perforated-patch mode (Table 1);

^b% of channels associated with 3 or more other channels in patch. BK clustering is the extent of BK channel clustering.

^cFrom Fig. 8A;

^dfrom Fig. 8B;

^efrom Fig. 8F. Cluster colocalization is colocalization of BK clusters with clusters of cholera toxin.

^fFrom Fig. 9A;

^gfrom Fig. 9B;

^hfrom Fig. 9F.

^*Compared with LTH fetus (P < 0.05).