. Zinc in Male Reproductive System
For men who plans to have a family, zinc is important for their reproductive system. Zinc is mostly found in the prostate gland (Oldereid, Thomassen, Attramadal, Olaisen, & Purvis, 1993). It is a small size gland that is located in the pelvis which is in the middle of penis and bladder. Testicular development, sperm maturation and testosterone synthesis are dependent to zinc. Low testosterone and low concentration and mortality of sperm may be due to zinc deficiency. Low concentration of zinc can give a bad effect to prostate gland which leads to an infection (prostatis) where the size of prostate gland becomes swollen (Bhowmik & Chiranjib, 2010). It is known as Benign Prostate Enlargement (BPE) whereby the prostate gland will press the bladder and urethra. When the urine passes through it, there will be difficulties in excreting but somehow it is not cancer. Male reproductive system is related to production of semen. Prostate gland is like a factory for production of semen. Semen is a mixture of sperm cells and other fluids. The fluid itself contains zinc which comes with selenium that is secreted by the prostate gland (Oldereid, Thomassen, & Purvis, 1998). Changes in amount of zinc in body parts can influence the sperm proliferation, maturation and viability (Teliiman et al., 2000). In addition, when the level of concentration of zinc is insufficient, it will prevent the production of luteinizing and follicle stimulating hormones from pituitary gland which is related to testosterone production (Bhowmik & Chiranjib, 2010). Hormones plays a big role in the reproduction system and it can also affect the increase or decreas(Hamdi, Nassif, & Ardawi, 1997)e of weight. Testicular development is important in the production of testosterone’s hormone. A study reported that testicular failure is related to zinc deficiency (Endre L. et al,1990;Hamdi et al., 1997). This statement was proven after conducting the experiment on rats for 6 weeks where the result showed the concentration of testosterone and progesterone to decrease but increase in follicle stimulating hormone (FSH) serum. Severe zinc deficiency also depletes the production of normal germ cell which are dependent on Sertoli cell hormone stimulation (Dym M. et al,1971;Ressell L. et al,1987;Hamdi et al., 1997). However, the failure in testicular growth are not only affected by the amount of zinc but it is also affected by protein and energy intake due to loss of appetite.
Based on the experiment conducted, severe zinc deficiency can weaken spermatogenesis. Spermatogenesis is a mechanism for production of sperm cell in testes by developing the germ cells in seminiferous tubules into haploid spermatozoa. Meanwhile, seminiferous tubules are shrunken and the weight of testicular is decreased.
i.Toxicity of zinc oxide nanoparticle in male reproductive system.
Zinc oxide nanoparticle (ZnONp) moves freely in the surroundings. It plays a role in various industries including in cosmetics, pigments, biosensors, bioimaging, drug delivery and antibacterial agents. Impairment of blood-testes barrier is the consequence from zinc oxide nanoparticle which decreases the expression of the gap junction proteins in Sertoli cells. Meanwhile, zinc oxide nanoparticle changes the structure of cell membrane and mitochondrial outer membrane of Sertoli cell in-order-to disrupt blood-testes barrier. It leads to an increase in the activity of reactive oxygen species or oxidative stress activity in Sertoli cell. Activation of oxidative stress cause secretion of cytokine to occur which can damage the blood-testes barrier. Blood-testes barrier is located in between Sertoli cells which isolates further developed stage of germ cells. (wikipedia)