No abstract

Aspartame is one of the most common consumed artificial sweeteners utilized in many food products and beverages. It has been indicated that long‐term consumption of aspartame leads to reproductive toxicity but its mechanism is not well‐clear. In this study we investigated mechanism of aspartame‐induced reproductive toxicity in male mice. For this purpose, 36 NMRI mature male mice received three doses of 40, 80, and 160 mg/kg body weight of aspartame, respectively per day by gavage for 90 days and also a control group was considered which received 0.5 mL of normal saline as the same route. The results revealed that long‐term administration of aspartame at high doses significantly (P < .05) reduced gonadosomatic index, serum concentration of pituitary‐testicular axis hormones (FSH, LH, and testosterone). It also decreased sperm parameters and total antioxidant capacity, antioxidant enzyme activities (superoxide dismutase, catalase, and glutathione peroxidase), while it caused increase in nitric oxide and malondialdehyde levels in testis tissue and sperm samples. Also, it decreased attenuated testicular histomorphometric indices (tubular differentiation index, spermiogenesis index, and repopulation index), and steroidogenic foci, while increased mRNA damages and apoptosis rate, downregulated antiapoptotic (Bcl‐2) and upregulated proapoptotic (P53, BAX, and caspase‐3) mediators respectively in testis. These findings indicated that consumption of aspartame for a long period results in male reproductive toxicity by decrease in serum concentration of pituitary‐testis axis hormones and induction of oxidative stress and apoptosis in testis.

This article describes the histological and mucin histochemical properties of the small intestine of the Persian squirrel (Sciurus anomalus). This species is widely distributed in the Middle East and can be found as a companion animal. The histological studies revealed that the plicae circulares were not visible in the tunica mucosa. The maximum height and width of the villi were observed in the duodenum, which then decreased toward the ileum. The muscularis mucosa was scattered, whereas the tunica submucosa was composed of dense connective tissue. The lymphatic nodules were seen in the submucosa of the distal part of the jejunum and ileum, and Brunner's glands were embedded in the initial portion of the duodenum. The tunica muscularis was significantly thicker in the ileum, and the circular muscle layer was thicker than the longitudinal muscle layer throughout the entire length of the small intestine. The mucin histochemistry, which was examined using the periodic acid-Schiff (PAS) and alcian blue (AB) (pH 1.0 and 2.5) and also PAS-AB (pH 2.5) and aldehyde fuchsin-AB (pH 2.5) techniques coupled with methylation and saponification reaction for some sections, showed that the small intestine mucous content included both carboxylated and sulfated acidic mucins with few neutral mucins. The results of this study contribute to the knowledge of the histological and histochemical characteristics of the gastrointestinal tracts of exotic mammals and provide data for comparison with other mammals.

Phenol is a common industrial and ubiquitous environmental chemical which is used to synthesize resins and plastics. Due to its anesthetic and disinfectant properties, phenol is also widely used in pharmaceutical products. Since there were no adequate data about phenol immunotoxicity, the purpose of the present study is to investigate its toxic effects on the histological structures of the lymphoid organs in the mice. A total of 80 mice were randomly distributed into one control group and three experimental groups. The control group received only distilled water, whereas experimental groups were orally administered phenol at the concentrations of 80, 180, and 320 mg/kg/day, respectively. After 28 consecutive days, tissue samples were taken and histological changes of the spleens, thymuses, adrenal glands, and lymph nodes were examined using optical microscopy. The results showed that in the phenol treated animals; splenic megakaryocyte counts increased, the diameter of the splenic follicles decreased, the thymocyte population in both cortex and medulla reduced, the thickness of the reticular layers of adrenal gland increased and lymphatic cells populations in the lymph node were reduced, significantly (P < 0.01). Also, remarkable histological changes were noted in the various lymphatic organs of the treated mice. Overall, present findings give some histological evidences that selected qualitative and quantitative parameters of the lymphatic organs were significantly altered by phenol administration. In conclusion, the significant decreases of the immune cell populations together with histological alterations in the immunocompetent organs of the mice exposed to phenol indicate the immunosuppressive and immunotoxic properties of this chemical material.

The present study made an attempt to measure the cortisol content, as an indicator of stress response, in rainbow trout embryos which were exposed to different densities and handling stress (air exposure) during incubation. The three densities of experimental embryos at early development stages were considered as 2.55 embryos/cm(2) (low density), 5.10 embryos/cm(2) (normal density) and 7.65 embryos/cm(2) (high density). The cortisol content of eggs (5.09 ± 0.12 ng/g) decreased to 3.68 ± 0.14 ng/g in newly fertilized eggs. Resting level of cortisol dropped at three densities by day 18 of post fertilization. Then, cortisol increased at hatching stage to 1.16 ± 0.11, 1.20 ± 0.12 and 1.21 ± 0.14 ng/g at low, normal and high densities, respectively. There were no statistically significant differences between cortisol concentrations in three densities. The acute handling stress test (5-min out-of-water), conducted on embryos (48 h post fertilization, organogenesis and eyed stage) in three densities, revealed no differences in whole-body cortisol levels between stressed and unstressed experimental groups. At hatching stage in low-density group, level of cortisol increased but the difference with the pre-stress levels was not statistically significant. Furthermore, significant differences in cortisol levels of stressed and unstressed embryos were detected on hatching in normal and high density groups [1.20 ± 0.12 at time 0-1.49 ± 0.11 ng/g at 1 hps (hours post stress) and from 1.21 ± 0.14 at time 0 to 1.53 ± 0.10 ng/g at 3 hps, respectively]. The results showed no difference in profile of cortisol in different densities, but acute stress conducted on embryos, incubated in different densities, revealed differences in cortisol stress response at hatching between normal and high density, which lead to cortisol increase at hatching time. It indicates that the lag time in the cortisol response to stressors immediately after hatching does not occur when the siblings were stressed during the embryo stage. Results, finally, indicated that hypothalamus-pituitary-interrenal axis was active and responded to an acute stressor under normal and high density, but it is unresponsive to a stressor around hatching under low density.