Isolation and culture of highly enriched populations of Leydig cells from guinea-pig (Cavia porcellus) testes

An autofluorescence-based isolation of Leydig cells for testosterone deficiency treatment

Effective procedures for the purification of Leydig cells (LCs) can facilitate functional studies and transplantation therapies. However, current methods to purify LCs from testes are still far from satisfactory. Here, we found that testicular autofluorescence existed in the interstitium along with the gradual maturation of LCs from birth to adulthood. These autofluorescent cells were further isolated by fluorescence-activated cell sorting (FACS) and determined to be composed of LCs and macrophages. To further purify LCs, we combined two fluorescence channels of FACS and successfully separated LCs and macrophages. Of note, we confirmed that the obtained LCs not only possessed high purity, viability and quantity but also had intact steroidogenic activity and excellent responsiveness to luteinizing hormone. Moreover, subcutaneous transplantation of isolated LCs could alleviate the symptoms of testosterone deficiency in castrated mice. In summary, we established an effective autofluorescence-based method for isolating LCs. This method will aid in the future success of using LCs for basic and translational applications.

Reproductive toxicity assessment of surface water of the Tai section of the Yangtze River, China by in vitro bioassays coupled with chemical analysis

Reproductive toxicity of organic extracts of the surface water from the Tai section of the Yangtze River was assessed by in vitro cytotoxity assays and selected persistent organic pollutants including PCBs, OCPs and PAHs were quantified by instrumental analysis. Eleven of the US EPA priority PAHs were detected. Individual PAHs were found to range from 0.7 to 20 ng/L. Concentrations of BaP did not exceed the national drinking water source quality standard of China. However, a 286-fold concentrated organic extract induced significant reproductive toxicity in adult male rats. The morphology of cells, MTT assay and LDH release assay were all affected by exposure to the organic extracts of water. The results of the reproductive toxicity indicated that PAHs posed the greatest risk of the chemicals studied. The compounds present in the water could be bioconcentrated and result in adverse effects.

In vitro assessment of reproductive toxicity on rats induced by organic contaminants of source water

The safety of drinking water attracts more and more attention these years. This study focused on the reproductive toxicity of source water in Jiangsu Province, China. The organic contaminants of source water are capable of bioaccumulating and cause health effects on human beings. The toxicological tests on Spermatogenic cells, Sertoli cells and Leydig cells of male rats showed that source water extracts can reduce testicular cells membrane integrity and depress cell viability significantly. Among these testicular cells, Leydig cells are most sensitive to organic contaminants and the testosterone secretion of Leydig cells is evidently disturbed correspondingly. The phenols in the source water may be chiefly responsible for the reproductive toxicity. These data indicated that chronic reproductive toxicity of source water cannot be overlooked and action should be taken to protect human health from the threat of organic pollution of source water.

The reproductive toxicity of organic compounds extracted from drinking water sources on Sprague Dawley rats: an in vitro study

The safety of drinking water always causes worldwide concern. Water pollution increases with urban development and industrialization in developing countries. During recent decades, increasing numbers of environmental organic compounds have been found in aquatic environments. These organic compounds are capable of bioaccumulating to much higher concentrations in food webs and cause health effects on human beings. Reproductive impairment is one of the commonest consequences of environmental pollution. Our goal was to investigate the reproductive toxicity of organic compounds extracted from surface water samples collected in drinking water sources. This study focused on the surface water in lower Yangtze River and Taihu Lake, which act as drinking water sources of Jiangsu province, one of the most rapidly developing regions in China. We used solid-phase extraction (SPE) to condense organic compounds by 286 times from natural surface water samples and established in vitro system to evaluate their effects on reproductive system. We found that organic compounds destroyed the plasma membrane integrity of Sertoli cells and Spermatogenic cells to a certain degree and significantly depressed viability of Sertoli cells and Spermatogenic cells as well. Accordingly, the proportion of apoptotic Sertoli cells and dead Spermatogenic cells enhanced markedly. Although viability of organic-compound-treated Leydig cells did not come down remarkably, testosterone production of Leydig cells decreased evidently. These results suggest that accumulated comprehensive effects of organic compounds in surface water of drinking water sources may induce spermatogenesis malfunction and reduction of testosterone production in the long term.

Elevated concentrations of ascorbate and normoxia suppress testosterone production in cultured guinea pig Leydig cells

In recent years, several metabolic roles have been proposed for vitamin C. Recent information suggests a strong causal relationship between high endogenous levels of ascorbic acid and changes in normal reproductive biology. Using highly enriched populations of guinea pig Leydig cells, we have found that elevated levels (50 to 500 microM) of ascorbate significantly (P < 0.01) depressed testosterone production in a dose-dependent manner while low levels (0 to 10 microM) were without effect. Leydig cells incubated under hypoxic (3% oxygen) culture conditions produced significantly (P < 0.01) more testosterone than similar cells cultured under normoxic (19% oxygen) conditions. The results of this study suggest that high concentrations of ascorbate and normoxic culture conditions suppress testosterone production in isolated Leydig cells. Thus, it would seem that there exists a delicate balance between normal metabolic requirements for vitamin C and excessive ascorbate levels that might alter normal gonadal reproductive events.