Postulated Human Sperm Count Decline May Involve Historic Elimination of Juvenile Iodine Deficiency: A New Hypothesis with Experimental Evidence in the Rat
| Autor: | J. W. Crissman, M. Sue Marty, Paul S. Cooke, A. B. Liberacki, Rex A. Hess |
|---|---|
| Rok vydání: | 2000 |
| Předmět: |
Male
medicine.medical_specialty Goiter media_common.quotation_subject chemistry.chemical_element Biology Toxicology Iodine Hypothyroidism Pregnancy Internal medicine Testis Toxicity Tests medicine Animals Humans Goitrogen Sperm motility media_common Sertoli Cells Sperm Count Body Weight Organ Size medicine.disease Sertoli cell Spermatids Spermatozoa Sperm Iodine deficiency Diet Rats Philosophy Thyroxine Fertility Endocrinology medicine.anatomical_structure Animals Newborn chemistry Sperm Motility Triiodothyronine Female Reproduction |
| Zdroj: | Toxicological Sciences. 53:400-410 |
| ISSN: | 1096-0929 |
| DOI: | 10.1093/toxsci/53.2.400 |
| Popis: | Human sperm count studies, historic dietary iodination, and an animal model where neonatal goitrogen administration causes unprecedented testis enlargement, together suggest an hypothesis relevant to the postulated fall in human sperm counts. We present the hypothesis with a supporting study extending the model to include iodine deficiency. In a one-generation rat reproduction study, dams were fed an iodine sufficient (control, 200 ppb I) or deficient (low iodine diet [LID],20 ppb I) diet from prebreeding through weaning, when male offspring were divided into three groups: 1) controls from iodine sufficient dams, 2) neonatal LID (NLID) from the LID dams, fed control diet postweaning, and 3) chronic LID (CLID) from LID dams, fed a moderate LID (40 ppb I) postweaning. F1 males were euthanized on postnatal day (PND) 133+/-1. Each of the three diet groups comprised two subgroups in which testicular parameters were evaluated: 1) daily sperm production (DSP), sperm motility, morphology, and histopathology, and 2) Sertoli cell and round spermatid morphometry. In the first subgroup, NLID and CLID testes weights were 8.5% and 14.0% heavier than their unusually heavy controls (3.921 g; historical control mean approximately 3.5 g), with proportional DSP increases. Sperm motility, morphology, and testis histopathology were unaffected. In the morphometry subgroup, respective increases in NLID and CLID rats included testes weights (+28.6% and +20.3%), Sertoli cells (+24.8% and +23.9%), and round spermatids (+20.4% and +15.8%). The results indicate that neonatal iodine deficiency can significantly increase spermatogenic function in rats, and support our hypothesis concerning human sperm counts. |
| Databáze: | OpenAIRE |
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