Diazepam administration prevents testosterone decrease and lipofuscin accumulation in testis of mouse exposed to chronic noise stress

Abstract

Lipofuscin is an autofluorescent and undegradable material, which accumulates in tissues during ageing and under different types of stress. Among these, oxidative stress represents a major trigger for lipofuscin formation. However, prolonged noise exposure is also an effective stressful stimuli. Diazepam may inhibit lipofuscinogenesis in liver and prevent the noise-induced reduction of the steroidogenesis in the adrenal gland. The aim of the study was to ascertain whether chronic noise exposure causes lipofuscin accumulation in mouse testis, and to evaluate the effects of diazepam administration. Eight-week old mice were either exposed for 6 weeks (6 h day(-1)) to white-noise (group A), or received diazepam (3 mg kg(-1), i.p.) before noise exposures (group B), while a further group was used as control (group C). Light fluorescence and transmission electron microscopy revealed lipofuscin in large amounts in the Leydig cells in mice of group A, which concomitantly had low serum testosterone levels; pre-treatment with diazepam occluded both effects. The present study indicates that: (i) chronic noise exposure causes lipofuscin accumulation at the level of the Leydig cells and a decrease in testosterone; (ii) all these effects are suppressed by pre-treatment with diazepam. As the Leydig cells represent the only cellular type of the interstitial testicular tissue having peripheral benzodiazepine receptors, these results could be explained by the capacity of the peripheral benzodiazepine receptors to prevent reactive oxygen species damage and to increase the resistance of these cells to oxidative stress.

Characterization and Quenching of Autofluorescence in Piglet Testis Tissue and Cells

“…In addition to aging, stress has also been cited as a potential reason for accumulation of lipofuscin. In mice under chronic stress treatment (noise exposure), similar granules were reported to form and accumulate particularly in Leydig cells, and lipofuscin was suggested as the fluorescent substance in the granules [32]. While aging or chronic stress is unlikely causes of lipofuscin accumulation in the cells of newborn animals, perhaps other factors may also regulate the accumulation of lipofuscin or lipofuscin-like pigments in the neonatal testes.…”

Przewlekła ekspozycja na hałas a niedobór testosteronu — metaanaliza i metaregresja wyników badań na gryzoniach

“…Due to limited full-text access, for the study of Rajabzadeh et al [25] we imputed the exposure based on previous work of the authors with a similar design. It should be noted that for the meta-analysis we considered only those experimental groups which did not receive other interventions, and disregarded combined exposures of noise and formaldehyde vapour [31], diazepam [32], vitamins C and E [33] or honey and vitamin E [25]. However, for Armario & Castellanos [30], we had to include the combined effect of noise and light exposures, which should be borne in mind.…”

“…All studies used validated and reliable methods (ELISA, RIA) to measure serum T levels. Some carried out histomorphological and microscopic analyses on the testes, assessed sperm parameters or pregnancy in female rats [31][32][33][34], but those outcomes were outside this study's scope.…”

Developmental Characteristics of Rat Testicular Tissue and the Impact of Chronic Noise Stress Exposure in the Prenatal and Postnatal Periods

“…Claims have been raised that noise stress exposure could have an adverse effect on male reproductive organs. Several studies reported structural and functional affection of testicular tissue due to noise stress exposure in adult males [5][6][7][8][9]. However, adverse effects of chronic noise stress exposure on the testis in prenatal or pre-pubertal periods are deficient.…”