Table 1.

Key characteristics of male reproductive toxicants.

Key characteristic	Examples of relevant evidence
1. Alters germ cell development, function, or death	Increased germ cell apoptosis; alterations in sperm acrosome reaction and motility
2. Alters somatic cell development, functions, or death	Increased Sertoli cell apoptosis; alterations in Sertoli cell functions, cytoskeleton, and interactions with germ cells; alterations in Leydig cell development
3. Alters production and levels of reproductive hormones	Decreased Leydig cell steroidogenic functions; increased hepatic metabolism and excretion of sex hormones
4. Alters hormone receptor levels/functions	Androgen receptor antagonism, estrogen receptor activation, decreased LH receptor expression
5. Is genotoxic	DNA damage, chromosome fragmentation, altered sperm cell chromosome numbers
6. Induces epigenetic alterations	Altered sperm ncRNAs, germ cell DNA methylation patterns, and histone retention sites
7 Induces oxidative stress	Reduced tissue antioxidant levels
8. Induces inflammation	Increased testicular expression of pro-inflammatory markers and prostaglandin levels

Note: LH, luteinizing hormone; ncRNA, noncoding RNA.