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

Abstract

Objectives

To investigate the effects of chronic stress on bladder morphology and the impact of food preference (standard or comfort foods) on the bladder of stressed rats.

Methods

In total, 32 Wistar male rats (3 months old) were divided into four groups: control (C), stressed (S), control + comfort food (C + CF), and stressed + comfort food (S + CF). Groups C and C + CF were maintained under normal conditions, while groups S and S + CF were subjected to chronic stress by the restraint method. Groups C and S received standard rat chow, while groups C + CF and S + CF received comfort food (Froot Loops®) and standard chow. The stress stimuli were induced daily for 2 h over 8 weeks. After 8 weeks, all animals were killed, and the bladders were removed and used for histomorphometric analysis.

Results

Body mass was similar among the groups. Stress did not promote differences regarding food intake, but animals receiving comfort food showed higher calories intake (in kcal/Kg) than animals receiving only standard chow. The C + CF and S + CF groups preferred comfort food over the standard chow; this preference was higher in the S + CF than in the C + CF group. The surface density of smooth muscle was reduced in stressed animals, while connective tissue and elastic system fiber content were increased in stressed groups. Further, epithelial height was increased in rats submitted to chronic stress. The surface density of elastic system fibers was decreased by the consumption of comfort food.

Conclusions

Chronic stress induces morphological modifications on the bladder wall and epithelium. These modifications may be related to lower urinary tract symptoms. Additionally, chronic stress caused a higher preference for comfort food intake which did not ameliorate or aggravate the stress-induced bladder alterations.

Keywords:

• Bladder
• chronic stress
• comfort food
• epithelial height
• morphometry
• surface density

Acknowledgments

This study was supported by grants from the Foundation for Research Support of Rio de Janeiro (FAPERJ), the Coordination for the Improvement of Higher Education Personnel (CAPES), and the National Council for Scientific and Technological Development (CNPq). These foundations were not involved in the study design, data collection, analysis, and interpretation, drafting of the manuscript, and the decision to submit for publication.

Disclosure statement

The authors declare no conflicts of interest.

Additional information

Funding

Foundation for Research Support of Rio de Janeiro (FAPERJ), the Coordination for the Improvement of Higher Education Personnel (CAPES), and the National Council for Scientific and Technological Development (CNPq).

Notes on contributors

Roger G. Marchon

Roger G. Marchon is a recently graduated PhD in the Urogenital Research Unit, State University of Rio de Janeiro. This manuscript is part of his thesis.

Bianca M. Gregório

Bianca M. Gregório is an associate Professor in the Urogenital Research Unit, State University of Rio de Janeiro. Her work mainly focuses on nutritional aspects related to the urogenital organs.

Marco A. Pereira-Sampaio

Marco A. Pereira-Sampaio is an associate Professor at the Department of Morphology, Federal Fluminense University and a collaborator at the Urogenital Research Unit, State University of Rio de Janeiro. His work focuses on morphological aspects of animal models.

Waldemar S. Costa

Waldemar S. Costa is an emeritus Professor in the Urogenital Research Unit, State University of Rio de Janeiro. His work mainly focuses on histological and morphometrical evaluation of the urogenital organs.

Francisco J. Sampaio

Francisco J. Sampaio is a full Professor, and head of the Urogenital Research Unit, State University of Rio de Janeiro. His work investigates the morphological aspects of the urogenital system at normal and altered conditions in humans and animal models.

Diogo B. De Souza

Diogo B. De Souza is an associate Professor in the Urogenital Research Unit, State University of Rio de Janeiro. He has been dedicated to study the urogenital organs under different conditions in animal models. Among his research lines, one is to study the impact of chronic stress on the kidney, testis, penis, and bladder.