Adverse Effects of some of the Most Widely used Metal Nanoparticles on the Reproductive System

Nanotechnology, which allows the manipulation of molecular dimensions, is used in many aspects of human life, from industrial to medical and therapeutic aspects. Features of nanoparticles and their unique capabilities have attracted a lot of attention. Among nanotechnology structures, metal nanoparticles have been widely used in many aspects of industry and medicine. The unique properties of these nanoparticles make possible to produce and expand them on a large scale, thus making the possibility of exposure to these nanoparticles more likely. Nanotechnology and nanoparticles like a double-edged sword despite its many benefits, it also has a number of disadvantages. One of the most important of these disadvantages is their toxicity. This toxicity may have adverse effects on the environment and humans. One of the most important adverse effects of nanoparticles is adverse effects on the reproductive system. In this paper, the adverse effects of some of the most widely used metal nanoparticles on the reproductive system are described. These adverse effects can be on: sexual behaviors, sexual organs, sperm count, sperm motility, sperm shape, sperm maturity, ovarian and follicle maturation, their fertility rate and also the level of sex hormones in men and women. The adverse effects of these nanoparticles and their toxicity on a variety of tissues and organs lead us to use safer nanoparticles.

Histomorphological Comparisons and Expression Patterns of BOLL Gene in Sheep Testes at Different Development Stages

BOLL is implicated in mammalian testicular function maintenance and spermatogenesis. To understand the expression patterns and biological functions of sheep BOLL, we examined the expression and immunolocalization of BOLL in the developing testes of Small-Tail Han sheep aged 0 days (D0), 2 months (2M), 5 months (5M), 1 year (1Y), and 2 years (2Y), by qPCR, Western blot, and immunohistochemistry methods. Firstly, morphological studies revealed that, in addition to spermatogonia, ordered and clear spermatocytes, as well as round and elongated spermatids and sperm, were found in the 1Y and 2Y testicular seminiferous tubules of the sheep testes, compared with the D0, 2M, and 5M testes, as analyzed by hematoxylin and eosin (H&E) staining. The diameter and area of the seminiferous tubules, epithelial thickness, and the area and perimeter of the tubule lumens gradually increased with age. BOLL was specifically expressed in testes and upregulation of BOLL transcript expression was higher in the testes of the 1Y and 2Y groups than in those of the D0, 2M, and 5M groups. Similarly, BOLL protein was expressed mainly in the 1Y and 2Y testes, ranging from primary spermatocytes to round spermatids, as well as in the spermatozoa. This study is the first demonstration that sheep BOLL might serve as a key regulator of the spermiogenesis involved in sperm maturity, in addition to its role as a crucial meiotic regulator.

Cyclic AMP phosphodiesterase: a regulator of forward motility initiation during epididymal sperm maturation

The concentrations of cAMP, cAMP phosphodiesterase (PDE) activity, and the effect of theophylline in vitro on the forward motility (FM) of maturing goat epididymal sperm have been analyzed. cAMP levels increased slowly during transit of the cells from the caput to the proximal cauda, although they acquired a minimal degree of forward progression. The last phase of sperm transit (proximal to distal cauda) was associated with a concomitant sharp rise in the level of both c AMP as well as flagellar motility. PDE activity progressively decreased (approximately threefold) during epididymal maturation, being minimal in mature cauda sperm. Theophylline (30 mM), a specific inhibitor of PDE, markedly activated (10-fold or greater) motility of the sperm derived from proximal-corpus, mid-corpus, distal-corpus, and proximal-cauda epididymides. FM of the native mature caudal sperm was similar to that of the theophylline-treated proximal-cauda sperm. The terminal stage of sperm maturity (proximal to distal cauda) was associated with a markedly reduced level of theophylline-dependent motility activation (approximately 50%). The data are consistent with the view that PDE plays an important role in the initiation of motility during epididymal sperm maturation.Key words: epididymal sperm, cyclic AMP, cyclic AMP phosphodiesterase, flagellar motility, theophylline