Genetic Background Strongly Influences the Bone Phenotype of P2X7 Receptor Knockout Mice

Table 2

Histomorphometric analysis for B6 and BALB P2X7^+/+ and P2X7^−/− mice.

B6	B6^+/+		B6^−/−		𝑡-Test
Vertebrae	Mean	SEM	Mean	SEM	𝑃
𝑁	12		8
MS/BS%	43.8	2.9	42.5	3.9	0.796
MAR (μm/day)	1.07	0.03	1.00	0.04	0.077
ES/BS (%)	7.9	0.4	9.1	0.7	0.180
BV/TV (%)	17.7	1.5	20.4	0.9	0.122
Tb.Th. (μm)	32.8	1.1	36.5	0.7	0.011
C.Th. (μm)	93.0	3.6	93.7	4.8	0.917
Tibia	Mean	SEM	Mean	SEM	𝑃
𝑁	12		8
MS/BS%	46.1	2.1	44	2.4	0.517
MAR (μm/day)	1.16	0.03	1.2	0.04	0.378
ES/BS (%)	8.3	0.6	8.0	0.3	0.676
BV/TV (%)	10.0	1.7	13.2	1.7	0.197
Tb.Th. (μm)	32.3	1.1	35.5	1.7	0.138
C.Th. (μm)	127.4	3.8	162.6	6.1	<0.001
BALB/cJ	BALB/cJ^+/+		BALB/cJ^−/−		𝑡-Test
Tibia	Mean	SEM	Mean	SEM	𝑡-Test
𝑁	7		7
MS/BS%	44.8	5.7	53.4	4.1	0.267
MAR (μm/day)	1.00	0.03	ND		—
ES/BS (%)	10.15	0.5	9.9	0.9	0.791
BV/TV (%)	8.7	1.7	9.5	1.9	0.766
Tb.Th. (μm)	31.1	2.1	33.1	1.1	0.423
C.Th. (μm)	148.9	10.4	139.8	8.9	0.517

Changes in histomorphometric parameters in P2X7^−/− compared to P2X7^+/+ in the tibia and vertebral (only B6). Displayed as mean ± SE for the group. The direction of changes is equal in the different regions of the B6 mice, besides MAR where it is decreased in the vertebral region of P2X7^−/− and decreased in the tibia. The ES/BS (%) has the opposite directions in vertebrae and tibia. Besides the cortical thickness and MS/BS (%) the directions of changes are the opposite in the BALB mice compared to the B6 mice. The size of the changes in the histomorphometric parameters P2X7^−/− mice is different in relation to region and strain analyzed. Significant differences from wild type animals at the 𝑃<0.05 levels, determined by Student 𝑡-test, are displayed.