Does pyrethroid exposure lower human semen quality? a systematic review and meta-analysis.

Pyrethroids are natural organic compounds extracted from flowers of pyrethrums and commonly used as domestic and commercial insecticides. Although it is effective in insect and parasitic control, its associated toxicity, including spermotoxicity, remains a challenge globally. Currently, the available reports on the effect of pyrethroids on semen quality are conflicting, hence an evaluation of its detrimental effect is pertinent.

Progesterone-Induced Sperm Release from the Oviduct Sperm Reservoir.

In mammalian females, after sperm are deposited in the reproductive tract, a fraction of sperm migrates to the lower oviduct (isthmus) and forms a sperm storage site known as the functional sperm reservoir. The interactions between sperm membrane proteins and oviduct epithelial cells facilitate sperm binding to the oviductal epithelium and retention in the reservoir. Sperm are bound by glycans that contain specific motifs present on isthmic epithelial cells.