The effects of fenclozic acid on fertility of male rats

Detection of Effects on Male Reproduction—A Literature Survey

The 1CH (International Conference on Harmonization of Technical Requirements for Registration of Pharmaceuticals for Human Use) Guideline for Detection of Toxicity to Reproduction for Medicinal Products, adopted at the Second ICH Conference in Orlando, FL, U.S.A., emphasized the need for research into the suitability of various methods for the detection of effects on fertility in males. The current project was undertaken to compare the efficiency of methods by evaluating reports in the open literature. The results of the examination of 117 substances or substance classes support the view that histopathology and organ weight analysis provide the best general-purpose means of detecting substances with the potential to affect male fertility. Examinations at up to 4 weeks of treatment appear to be as effective as examinations conducted at later times. Mating with females for detection of effects unrelated to interference with sperm production appears to provide an optimal combination because adding other methodologies does not materially improve the detection rate. As to the timing of the mating trial, a 2-week premating period is as efficient as mating at 4 weeks and apparently more efficient than mating after prolonged premating treatment.

Teratogens and the male. An analysis with special reference to herbicide exposure

A review of the experimental evidence and of the human clinical and epidemiological studies relating to possible teratogenesis after exposure of the male to toxic substances is presented. Toxic insults to the process of gametogenesis can occur either in the male or in the female. Temporary infertility can occur in males exposed to toxic substances, and teratospermia is well documented. An increased miscarriage rate among the wives of men chronically exposed to toxic substances has been reported. A number of experiments have been conducted to study the progeny of male mammals poisoned with proven mammalian teratogens. In none of these studies has the teratogenic syndrome (easily demonstrable as an effect of the drug or toxin when ingested by the pregnant mother) appeared in the offspring of a male who has been exposed to the toxin. Epidemiological studies in humans have given no positive evidence that the baseline congenital malformation rate of children is increased if the father has been exposed to toxic substances. The available evidence indicates that spermatogenesis is particularly resilient after exposure to various toxic chemicals.