1. Temporal changes in testis weight during the past 50 years in Japan
- Author
-
Jin Yoshimura, Kyu-Bom Koh, Kaoru Sagisaka, Hideki Fukata, Fujio Kayama, Masae Shiyomi, Shinichi Tanihara, Sanae Takeichi, Takahiko Kusakabe, Masatoshi Morita, Akihiko Hamamatsu, Takeshi Saito, Chisato Mori, and Noriko Nakamura
- Subjects
Adult ,Male ,medicine.medical_specialty ,Time Factors ,Younger age ,Adolescent ,Biology ,Internal medicine ,Testis ,medicine ,Humans ,Child ,Spermatogenesis ,Infertility, Male ,Aged ,Histological examination ,Aged, 80 and over ,Reproduction ,Infant ,Organ Size ,General Medicine ,Human physiology ,Middle Aged ,Endocrinology ,Male reproductive disorders ,Human reproductive system ,Child, Preschool ,Anatomy - Abstract
The ever-increasing presence of environmental toxicants and their disruptive effect on the reproductive systems of wildlife raises the question of possible damage to the human reproductive system. Using medicolegal data from over 20,000 Japanese men subjected to necropsy from 1948 to 1998, we investigated temporal changes in testis weight to find possible evidence of male reproductive disorders. We also carried out a histological examination of 747 testes collected from 1978 to 1998. Our detailed analyses of the development of testis weight over the past 50 years have revealed four clear phenomena: (i) the age at which testis weight reaches its maximum has decreased; (ii) peak weight showed a general increase until it started to decline in boys born after 1960; (iii) the decline-rate at which testis weight decreases after its peak has greatly accelerated; and (iv) the onset of increasing testis weight of boys has occurred at a progressively younger age. Our quantitative analyses of testis weight indicate the possibility of a subtle reproductive disorder in Japanese men, especially in those born after 1960. Together with the accelerated development and decline in testis weight during the past 50 years, the decline in peak weight might be indicative of a subtle interference of environmental toxicants with male reproductive organogenesis.
- Published
- 2002
- Full Text
- View/download PDF