Table 5.

Correlation analysis using Spearman's rho test and linear regression analysis of various parameters vs. body mass

	Correlation analysis		Regression analysis
	r	P	R2	a	b (SEM)
Heart weight	0.9879	< 0.0001	0.990	6.661	0.971 (0.034) NS
Nerve fibre length density	0.2121	0.5603	0.044	0.011	0.017 (0.028)
Axon length density	0.4303	0.2182	0.318	0.017	0.064 (0.033)
Nerve fibre length	0.9758	< 0.0001	0.986	9.262	1.040 (0.044) NS
Axon length	0.9758	< 0.0001	0.983	17.147	1.088 (0.043) NS
Mean number of axons per nerve fibre	0.6970	0.0306	0.6652	1.645	0.048 (0.012)
Volume of cardiomyocytes	0.9879	< 0.0001	0.989	3.254	0.961 (0.036) NS
Volume density of myofibrils	0.6485	0.0490	0.459	0.624	0.022 (0.009)
Volume of myofibrils	0.9879	< 0.0001	0.988	2.030	0.983 (0.039) NS
Volume density of mitochondria	−0.9030	0.0008	0.896	0.270	−0.076 (0.009)
Volume of mitochondria	0.9879	< 0.0001	0.989	0.878	0.885 (0.032)
Surface density of cardiomyocytes	−0.2485	0.4918	0.035	0.442	−0.008 (0.016)
Surface area of cardiomyocytes	0.9758	< 0.0001	0.991	1.850	0.963 (0.033) NS
Volume density of capillary lumen	−0.8303	0.0047	0.679	0.156	−0.099 (0.024)
Volume of capillary lumen	0.9879	< 0.0001	0.992	0.088	0.969 (0.030) NS
Length density of capillaries	−0.5273	0.1231	0.361	0.004	−0.042 (0.020)
Length of capillaries	0.9758	< 0.0001	0.982	17.581	0.929 (0.044) NS
Surface density of capillary endothelium	−0.7939	0.0088	0.569	0.104	−0.052 (0.016)
Surface area of capillary endothelium	0.9879	< 0.0001	0.989	0.444	0.920 (0.036) NS

NS, not significantly different from b = 1.