Effects of chronic stress on bladder morphology of rats and impact of comfort food diet as an ameliorating agent

Figures & data

Figure 1. Photomicrographs and graphics representing the connective tissue (shown in blue and pointed by arrowheads) and smooth muscle contents (shown in Pink and pointed by arrows) in the bladder wall of different groups. (A) Control group (B) Stressed group (C) Control + comfort food group (D) Stressed + comfort food group. Sections were stained using Masson’s trichrome and captured under 600× magnification. The higher presence of connective tissue (blue stained areas) indicates tissue fibrosis. (E) Connective tissue surface density, (F) smooth muscle surface density. Asterisks represents statistical differences (p = 0.0005) between stressed and control animals. Scale bar represents 75 µm.

Figure 2. Photomicrographs and graphics representing the elastic system fibers (shown as Fine purple lines and pointed by arrowheads) in the bladder wall of different groups. (A) Control group (B) Stressed group (C) Control + comfort food group (D) Stressed + comfort food group. Sections were stained using Weigert’s resorcin fuchsin and captured under 1000× magnification. (E) Results of elastic system fibers surface density. Asterisks represents statistical differences (p = 0.0013) between stressed and control animals. Hashtag represents statistical differences (p < 0.0001) between comfort food and standard chow fed animals. Scale bar represents 200 µm.

Figure 3. Photomicrographs and graphics representing the epithelial height in the bladder of different groups. The epithelium is marked (in random areas) by double-headed arrows to indicate the differences in epithelial height. (A) Control group (B) Stressed group (C) Control + comfort food group (D) Stressed + comfort food group. Sections were stained using Masson’s trichrome and captured under 600× magnification. (E) Results of epithelial height measurements. Asterisks represents statistical differences (p < 0.0001) between stressed and control animals. Scale bar represents 75 µm.

Table 1. Biometric data and bladder morphometric analysis of the experimental groups.

	C	S	C + CF		S + CF		p value*	p value**
Blood glucose – initial (mg/dL)	89.25 ± 9.19	98.63 ± 13.21	95.38 ± 14.69		89.29 ± 11.88		0.7162	0.7221
Blood glucose – final (mg/dL)	89.19 ± 7.95	96.13 ± 13.67	99.71 ± 13.41		90.57 ± 8.88		0.7914	0.5520
Body mass – initial (g)	319.1 ± 57.85	348.0 ± 29.63	373.0 ± 41.24		313.4 ± 24.90		0.2923	0.5054
Body mass – final (g)	388.10 ± 70.45	378.60 ± 43.53	388.10 ± 70.45		364.90 ± 34.29		0.0648	0.5443
Food intake (g)	27.77 ± 1.69	27.81 ± 1.95	26.51 ± 2.04		23.81 ± 1.67		0.0515	0.0004
Food intake (kcal/kg BM)	0.24 ± 0.01	0.24 ± 0.02	0.27 ± 0.03		0.25 ± 0.03		0.1819	0.0495
Food preference (g)	–	–	SC	CF	SC	CF	p value^#	p value^##
			9.69 ± 0.95	16.81 ± 1.51	7.36 ± 1.69	16.45 ± 1.89	<0.0001	<0.0001
Sv [smooth muscle] (%)	37.58 ± 2.05	32.53 ± 2.14	35.19 ± 3.26		33.95 ± 1.07		0.0005	0.5507
Sv [connective tissue] (%)	62.42 ± 2.05	67.47 ± 2.14	64.81 ± 3.26		66.05 ± 1.07		0.0005	0.5507
Sv [elastic system fibers] (%)	3.50 ± 0.69	4.34 ± 0.25	2.50 ± 0.57		3.08 ± 0.64		0.0013	<0.0001
Epithelial height (µm)	19.55 ± 3.58	26.04 ± 4.86	19.60 ± 1.37		26.17 ± 4.89		<0.0001	0.9484

C: Control group; S: Stressed group; C + CF: Control + comfort food group; S + CF: Stressed + comfort food group; BM: Body mass. SC: Standard chow. CF: Comfort food. *p value of stress effects. **p value of food effects. ^#p value of t test regarding food preference of C + CF group. ^##p value of t test regarding food preference of S + CF group. Data expressed as mean ± standard deviation.