Metal ions and human sperm mannose receptors

Abstract

Zinc and lead concentrations were measured in seminal plasma from fertile donors, infertile men with varicocoele and men undergoing work-ups for in vitro fertilization. Ejaculated spermatozoa from these subjects were incubated in vitro with various metal ions and/or dibromoethane and dibromochloropropane. Mannose receptor expression was correlated with metal and toxicant levels. Sperm distributions of potassium channels were compared with lead ions and calcium channels with zinc ions. Mannose receptor expression by capacitated spermatozoa increased linearly with seminal plasma zinc levels, and correlated inversely with lead levels. Cobalt had no effect on mannose receptor expression, but nickel had a concentration-dependent biphasic effect. Mannose receptor expression was not affected by dibromoethane and dibromochloropropane if the cholesterol content of the sperm membrane was high, but mannose receptor expression was decreased in low cholesterol spermatozoa by exposures below estimated permissive exposure limits. Potassium channels and lead ions co-localized over the entire head of human spermatozoa, while both calcium channels and zinc ions were confined to the equatorial segment of the head. Mannose receptor expression on the external surface of the human sperm plasma membrane is a biomarker for the effects of transition and heavy metals and organic toxicants on sperm fertility potential.

Cadmium Concentrations in Blood and Seminal Plasma: Correlations with Sperm Number and Motility in Three Male Populations (Infertility Patients, Artificial Insemination Donors, and Unselected Volunteers)

“…This finding is in contrast with our in vivo and in vitro studies of lead and zinc and other metals in seminal plasma (42,59,61,63,91), in which we found both seminal plasma lead and seminal plasma zinc levels to be correlated with expression of sperm functions required for fertilization of oocytes in IVF inseminations, with lead negatively correlated with expression of mannose receptors and progesterone-and mannosestimulated acrosome loss and positively with spontaneous acrosome reactions (59,63; S Benoff, unpublished observations). A negative relationship between seminal plasma lead levels and progesterone-stimulated acrosome loss was also detected in group 3 (general population volunteers) (S Benoff and GM Centola, unpublished observations).…”

Semen quality and reproductive endocrinal function related to blood lead levels in infertile painters

“…At the molecular level, mannose receptor expression by capacitated spermatozoa correlated inversely with lead levels (Benoff et al, 2000). The results of the studies on fertility rates are consistent in showing an association between lead and reduced fertility (Sallmén, 2001).…”

Notice of Retraction: Establishing an Assay to Measure the Enzymatic Activity of Human Glandular Kallikrein 2 in Human Seminal Plasma and Clinical Application

“…Recent studies have shown that the mannose receptors exist in human sperm membrane, and the level of zinc was negatively correlated to other trace elements [7]. Fuse and Robak-Chohubek also achieved the same conclusion.…”