Impaired Spermatogenesis

It is estimated that 6% of reproductive age men are infertile and that 90% of those are related to impaired spermatogenesis. 48 It is believed that impaired spermatogenesis is related to prenatal and neonatal exposures to endocrine disrupting chemicals. 49-50  

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It is widely accepted that men with testicular cancer have a higher incidence of abnormalities associated with impaired spermatogenesis, both in the cancerous testis but also in the contralateral testis. Men diagnosed as having testicular cancer often have very poor semen quality, with sperm concentrations of less than 10 million/ml compared to healthy men with > 50 million/ml." It is thought that gonadal function is abnormal even before testicular cancer develops, ... 

No studies were located regarding developmental effects in humans after inhalation exposure to mirex or chlordecone. Although impaired spermatogenesis among male workers exposed to... 

Human sexual function and fertility disorders include, e.g., spontaneous abortions, impaired spermatogenesis, menstrual disorders, impotence, and early menopause. 

No signihcant adverse effects to topical penciclovir have been reported. Oral famciclovir is generally well tolerated. Adverse effects include headache, nausea, and diarrhea. Confusion may occur, particularly in the elderly. Hallucinations and urticaria have been reported. Animal studies have indicated that chronic famciclovir administration may be tumorigenic and impair spermatogenesis. Dosage adjustment is necessary in individuals with renal impairment. 

Deficiency symptoms Bitot s spots, xerosis, night blindness, keratomalacia, diarrhoea, follicular hyperkeratosis, papular eruptions, drying of epidermis, urinary calculi, degeneration of testis, impaired spermatogenesis, sterility, abortion, impairment of smell and taste. 

The purpose of this chapter is to review the methods that are currently in use to evaluate sexual function and fertility. Sexual function and fertility are complex reproductive functions that can be affected by environmental exposures. Reproductive disorders include spontaneous abortions, impaired spermatogenesis, menstrual disorders, impotence, early menopause and others. Any disturbance in the integrity of the reproductive system can affect these functions. 

Sertoli cell tight junctions (Evans, 2007 Thomas, 1995 Thomas and Thomas, 2001). Exposure of male laboratory animals to organotin compounds has been associated with reduced testicular size, alterations in testicular morphology, and impaired spermatogenesis (Ema and Hirose, 2006 Evans, 2007). 

A small number of studies have reported that male rats fed aflatoxins developed testicular degeneration and impaired spermatogenesis, although no clear association with aflatoxins and clinical infertility was uncovered in one of these studies. 

The recently proposed testicular dysgenesis syndrome (TDS) hypothesizes that four maladies—hypospadias, cryptorchidism, impaired spermatogenesis, and testicular cancer—are all manifestations of disturbed prenatal testicular development. I86 87 TDS is believed to be connected to genetic and environmental factors, though this has not yet been demonstrated. All four conditions noted have been independently related to endocrine disrupting chemicals, and hence the association in TDS, which the authors of the most recent article on the subject conclude may be clinically manifest by a reduced sperm concentration. I87l... 

There is still debate about how, when, and to what extent varicocele affects fertility. A total of 10% of all men have a varicocele. Most are both asymptomatic and not associated with infertility. However, among infertile couples the incidence of a varicocele increases to 30% [7]. Why should the dilatation of the veins of the pampiniform plexus impair spermatogenesis A related question in patients with a unilateral varicocele, is how unilateral venous abnormality produces bilateral testicular dysfunction Several theories have been postulated to explain the pathophysiology of varicocele. The most popular among the theories involves the adverse effect of elevated testicular temperature on spermatogenesis [8]. Another theory is that reflux of adrenal or renal metabolites that could inhibit spermatogenesis reach the left testicle by back flow from... 

Three approaches to evaluating reproductive competence in Pb-exposed men, largely workplace exposures, have been elucidated direct gametotoxicity through impaired spermatogenesis and quality, assessment of altered time to pregnancy, and reproductive history. These three aspects are set forth in Table 14.5. In virtually all cases, these toxic effects occurred at the relatively higher exposure levels seen in the workplace. 

Mechanisins of tinJcolo fbanage. Ibxicants that impair spermatogenesis or the physical delivery of spermatozoa to the oocyte can interfm with reproduction (Table 12-1). 

The herb (vegetable) has been reported to cause contact dermatitis in humans. An aqueous suspension of the root at a sublethal dosage (8.7g/kg p.o. per day for 10 days) decreased body weight and impaired spermatogenesis in mice, whereas the threshold dosage (4.5 g/kg) had neither effect. ... 

Excessive cobalt can potentially interfere with normal spermatogenesis and even generalized hypoxia related to increased blood viscosity that affects the testes (Thomas, 1995 Evans, 2007). Chromium and vanadium have also been associated with adverse reproductive effects, and cis-platinum exposure has been associated with the death of spermatocytes and spermatids, as well as disruption of Sertoli cell tight jimctions (Thomas, 1995 Thomas and Thomas, 2001 Evans, 2007). Exposure of male laboratory animals to organotin compounds has been associated with reduced testicular size, alterations in testicular morphology, and impaired spermatogenesis (Ema and Hirose, 2006 Evans, 2007). 

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