Prolonged deleterious effects of neonatal handling on reproductive parameters of pubertal male rats
Renata Mazaro A and Teresa Lúcia Lamano-Carvalho B CA Department of Physiology, Medical School of Ribeirão Preto, University of São Paulo, Av. do Café s/n, 14040-904 Ribeirão Preto, SP, Brazil.
B Department of Morphology, Stomatology and Physiology, Dental School of Ribeirão Preto, University of São Paulo, Av. do Café s/n, 14040-904 Ribeirão Preto, SP, Brazil.
C Corresponding author. Email: tllc@forp.usp.br
Reproduction, Fertility and Development 18(4) 497-500 https://doi.org/10.1071/RD04076
Submitted: 21 July 2004 Accepted: 12 February 2006 Published: 4 April 2006
Abstract
The purpose of the present study was to investigate the long-lasting effects of neonatal handling on reproductive parameters of male rats. Neonatal handling (pups separated from their mothers, kept isolated at environmental temperature for 20 min and submitted to 1 min of tactile stimulation) was applied from post partum Days 1 to 14 (a stress-hyporesponsive period, SHRP) and the animals were killed at puberty (61 days of age). The number of mature spermatids and the daily sperm production were estimated in homogenates from the right testes and cauda epididymidis. Histometric parameters (diameter of seminiferous tubule, germinal epithelium thickness and number of Sertoli cells) were evaluated in paraplast sections of the left testes. The association of the slightly aversive stimuli applied during the SHRP proved to have lasting deleterious effects on male reproduction, causing lower testicular weight and reduced values of seminiferous tubule diameter and germinal epithelium thickness at puberty, which resulted in a 25% reduction in the daily sperm production and in the number of mature spermatids. Similarly, the number of Sertoli cells per tubular cross section was 20% smaller and the weight and number of spermatozoa were reduced more than 40% in the cauda epididymidis of animals handled.
Extra keywords: Sertoli cells, sperm production.
Acknowledgments
The authors are grateful to Dr A. B. Lucion for discussion of the neonatal handling design and to Edna A. S. Moraes for technical assistance.
Almeida, S. A. , Anselmo-Franci, J. A. , RosaESilva, A. A. , and Lamano-Carvalho, T. L. (1998a). Chronic intermittent immobilization of male rats throughout sexual development: a stress protocol. Exp. Physiol. 83, 701–704.
| PubMed |
Meaney, M. J. , Bhatnagar, S. , Larocque, S. , McCormick, C. , Shanks, N. , Sharma, S. , Smythe, J. , Viau, V. , and Plotsky, P. (1993). Individual differences in the hypothalamic–pituitary–adrenal stress response and hypothalamic CRF system. Ann. N. Y. Acad. Sci. 697, 70–75.
| PubMed |
Sharpe, R. M. , McKinnel, C. , Kivlin, C. , and Fisher, S. (2003). Proliferative and functional maturation of Sertoli cells, and their relevance to disorders of testis function in adulthood. Reproduction 125, 769–784.
| Crossref | GoogleScholarGoogle Scholar | PubMed |
Stratakis, C. A. , and Chrousos, G. A. (1995). Neuroendocrinology and pathophysiology of the stress system. Ann. N. Y. Acad. Sci. 771, 1–18.
| PubMed |
Wigger, A. , and Neumann, I. D. (1999). Periodic maternal deprivation induces gender-dependent alterations in behavior and neuroendocrine responses to emotional stress in adult rats. Physiol. Behav. 66, 293–302.
| Crossref | GoogleScholarGoogle Scholar | PubMed |
Wing, T. Y. , and Christensen, A. K. (1982). Morphometric studies on rat seminiferous tubules. Am. J. Anat. 165, 13–25.
| Crossref | GoogleScholarGoogle Scholar | PubMed |