Acessibilidade / Reportar erro

Undernutrition impairs the quality of growth plate and trabecular and cortical bones in growing rats1 1 Research performed at Laboratory of Bioengineering, Department of Biomechanics, Medicine and Rehabilitation of the Locomotor System, School of Medicine, Universidade de São Paulo (USP), Ribeirao Preto-SP, Brazil. Part of Master degree thesis, Postgraduate Program in Health Sciences Applied to the Locomotor System. Tutor: José Batista Volpon.

Abstract

Purpose:

To investigate the effects of dietary restriction on the growth plate and long bone tissue in growing rats.

Methods:

Sixty male Wistar rats were randomly assigned to two groups: Control (Con) and Diet-restricted (Res). After weaning, the Res rats were offered 50% of the chow ingested by the control (ad libitum food intake). The animals were subdivided into two subgroups with follow-ups up to 56 or 70 days. After euthanasia, the growth plate of tibias was analyzed by histomorphometry, micro-computed tomography, and mechanical test. The trabecular and compact bones were evaluated by histomorphometry, dual-energy X-ray absorptiometry, and micro-computed tomography (μCT). Real-time PCR was used to analyze gene expression.

Results:

Although dietary restriction did not alter gene expression, several phenotypic changes were seen in the growth plate; i.e., decrease in volume, reduction in total area and height, decrease in the area ossified zones, mechanical weakening, reduction in mass of trabecular and cortical bone, lower bone density, deterioration of the trabecular and cortical microarchitecture, and trabeculae with lower collagen deposition.

Conclusion:

Dietary restriction had severe detrimental effects on the growth plate and trabecular and cortical bone.

Key words:
Malnutrition; Growth Plate; Cancellous Bone; Cortical Bone; Rats

Sociedade Brasileira para o Desenvolvimento da Pesquisa em Cirurgia https://actacirbras.com.br/ - São Paulo - SP - Brazil
E-mail: actacirbras@gmail.com