Coronary vessels and cardiac myocytes of middle-aged rats demonstrate regional sex-specific adaptation in response to postmyocardial infarction remodeling

Table 3 Arteriolar diameter, numerical density, length density, volume densities, and the degree of arteriolar tortuosity in the left ventricle of shame and MI hearts from male (M) and female (F) rats

	Number	Diameter minimum, μm	N_A, counts/mm²	L_V, mm/mm³	Tortuosity, L_V/N_A	V_V, percent
LV free wall
M-Sham	7	15.7 ± 0.6	20.4 ± 1.3	54.6 ± 2.3	2.7 ± 0.1	1.22 ± 0.16
M-MI	7	16.4 ± 0.4	22.2 ± 1.4	66.8 ± 4.8^*	3.0 ± 0.1	1.55 ± 0.15
F-Sham	6	19.5 ± 0.7^§§§	6.9 ± 0.3^§§§	18.6 ± 1.6^§§§	2.7 ± 0.2	0.62 ± 0.03^§
F-MI	6	17.0 ± 0.4^*	9.3 ± 0.8^†††	23.7 ± 2.2^*†††	2.6 ± 0.2	0.63 ± 0.06^††
Septum
M-Sham	7	15.7 ± 0.3	17.5 ± 1.4	41.9 ± 1.6	2.4 ± 0.1	0.96 ± 0.05
M-MI	7	16.2 ± 0.3	21.2 ± 1.9	53.6 ± 5.7^*	2.5 ± 0.1	1.38 ± 0.11^*
F-Sham	6	17.9 ± 0.5^§§	11.0 ± 1.1^§	25.8 ± 1.4^§§	2.4 ± 0.2	0.84 ± 0.09
F-MI	6	16.8 ± 0.6	8.9 ± 0.9^†††	23.0 ± 2.2^†††	2.6 ± 0.1	0.61 ± 0.12^†††

Values are the mean ± SEM. n, number of rats; N_A, numerical density; L_V, length density; V_V, volume density. A two-way ANOVA revealed a statistically significant interaction between the effects of sex and the experimental model on the arteriolar diameter in LV free wall, F (1, 22) = 8.943, P = 0.009, and on arteriolar volume density in septum, F (1, 22) = 10.903, P = 0.005. ^*P < 0.05 vs. corresponding Sham group; ^§P < 0.05, ^§§P < 0.01, and ^§§§P < 0.001 vs. M-Sham; ^†P < 0.05, ^††P < 0.01, and ^†††P < 0.001 vs. M-MI.