Alteration of fertility endpoints in adult male F-344 rats by subchronic exposure to inhaled benzo(a)pyrene

Abstract

The objective of this study was to evaluate the reproductive risk associated with exposure of adult male Fisher-344 rats to inhaled benzo(a)pyrene (BaP). Rats were assigned randomly to a treatment or control group. Treatment consisted of sub-chronic exposure of rats via inhalation to 75μg BaP/ m 3 , 4 hours daily for 60 days, while control animals were unexposed (UNC). Blood samples were collected immediately after the cessation of exposures (time 0) and subsequently at 24, 48, and 72 hrs, to assess the effect of bioavailable BaP on plasma testosterone and luteinizing hormone (LH) concentrations. Rats were sacrificed after the last blood collection. Testes were harvested, weighed and prepared for histology and morphometric analysis, and cauda epididymides were isolated for the determination of progressive motility and density of stored spermatozoa. BaP exposure reduced testis weight compared with UNC (Mean ± SE; 2.01 ± 0.11 vs. 3.04 ± 0.16 g; P< 0.025), and caused significant reductions in the components of the steroidogenic and spermatogenic compartments of the testis. Progressive motility and mean density of stored spermatozoa were reduced (P< 0.05). Plasma testosterone concentrations were decreased by two-thirds in BaPexposed rats throughout the time periods studied compared with those of their UNC counterparts (P< 0.05), concomitant with increased concentrations of LH in BaP-exposed rats (P< 0.05). These data suggest that sub-chronic exposure to inhaled BaP contribute to reduced testicular and epididymal function in exposed rats.

The in vitro effect of benzo[a]pyrene on human sperm hyperactivation and acrosome reaction

“…(8), few studies have evaluated its possible effect on sperm motion characteristics. A study of adult male F-344 rats showed that subchronic exposure to inhaled benzo[a]pyrene contributed to reduced testicular and epididymal function (17). Because the motion characteristics, hyperactivation status, and acrosomal reaction of spermatozoa indicate functional status and fertilizing potential, it is worthwhile to note whether benzo[a]pyrene has any effect on these parameters.…”

Combined Effects of Dibutyl Phthalate (DBP) and Benzo(a)Pyrene on Fertility in Male Rats

“…Sections were stained with haematoxylin and eosin (HE), observed and evaluated on a light microscope (BX51) equipped photomicroscope (DP72; OLYMPUS) which coupled with a computerized morphometric planimetry system (DP72-BSW; OLYMPUS) to facilitate the measurement of tubule area and area percentage (volume percentage) occupied by seminiferous tubules. The percentage of seminiferous tubules was computed according to Ramesh (Ramesh et al, 2008).…”

“…Benzo(a)pyrene (Bap), a prototype of polycyclic aromatic hydrocarbon (PAH) that is released into the environment by industrial emission, has attracted worldwide attention as its toxic effect on male reproduction. It has been demonstrated that Bap can cause seminiferous tubules malformation, change the epididymis function and enzyme activity in testicular cells, induce DNA damage and synthesis inhibition in spermatogenic cells, and decrease serum testosterone level and the amount of spermatogenic cells and sperms (Zhu et al, 2010;Sipinen et al, 2010;Inyang et al, 2003;Mohammad Shah Alam et al, 2010;Ramesh et al, 2008).…”

Environmentally relevant concentrations of benzo[a]pyrene affect steroid levels and affect gonad of male scallop Chlamys farreri

“…Furthermore, the bioaccumulation and toxic metabolism of B[a]P can also induce oxidative stress at the both biomacromolecular and cellular level. PAHs or their metabolites might cause toxicity in male reproductive system, including changes in testosterone level, decreased sperm production and irregular arrangements of the seminiferous epithelium Chen et al, 2011;Chung et al, 2011;Ramesh et al, 2008).…”