Di(n‐butyl) phthalates (DBP) are endocrine‐disrupting chemicals (EDCs) implicated in a number of reproductive disorders in humans and rodents. Previously, we have shown that DBP effects is anti‐androgenic and causing alterations in seminiferous tubular histology and impairment of Leydig cell steroidogenesis in the avian model. However, the ultrastructural changes on the Sertoli cell remain unclear. The present study was designed to assess, morphologically, the dose‐dependent toxic effect of pre‐pubertal exposure of the plasticizer‐DBP, on the histology and ultrastructure of the Sertoli cell. DBP was administered to 10‐week old male quail birds by oral gavage, with a control group given corn oil vehicle(1mL/kg) only, while the other five experimental groups were fed (1, 10, 50, 200– and 400mg/kgbwt/d DBP(dissolved in corn oil) , for a period of 30days. Testes were fixed in Bouin's liquid or in a mixture of 2.5% glutaraldehyde and 2% formaldehyde for analysis under light and electron microscopes(TEM), respectively. Histologically, the basal Sertoli cell cytoplasm in high DBP dosage levels (200mg and 400mg/kgbwt/d), increasingly displayed aggregations of lipid droplets, but only a few in the apical Sertoli cell cytoplasm. In addition, there was marked vacuolations in the lining germinal epithelium. Ultrastructurally, there were notable, dose‐dependent changes seen in the Sertoli cell in DBP‐treated birds, with low dosage groups displaying no obvious structural changes, while the DBP high‐dose resulted in a remarkable accumulation of numerous, scattered or usually, closely packed lipid droplets, found predominantly in the basal part of the Sertoli cell cytoplasm. In addition, there were several mis‐shaped or swollen mitochondria with electron lucent areas, indicative of early cellular degeneration. These degenerating mitochondria were characterized by swelling and deformation of the tubular cristae, resulting in a “moth‐eaten” appearance. These findings showed that high dose of DBP (200 and 400mg/kgbwt/d) administered daily for 30days significantly resulted in degenerative characteristics, such as the increase in lipid droplets, intra‐epithelial vacuolations and mitochondrial damage in the Sertoli cell. Thus, this study has provided a clear evidence that alterations in Sertoli cell morphology and function were involved in spermatogenic failure induced by DBP, in this specie.Support or Funding InformationThe research was supported by Ahmadu Bello University Board of Research and grants from the South African Veterinary/Novartis Wildlife Foundation.This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.

This study provides detailed description of the gross morphology and distribution of the nerves arising from the cervical segments of the spinal cord of the African Giant Rat (AGR). Two (2) AGRs were used for this study. The rats were euthanized using halothane. The skin and superficial fascia were removed, and dissection of the muscles in the cervical region and thoracic limbs was carried out. The vertebral canal was opened by means of a rongeur. Eight (8) pairs of spinal nerves (C1–C8) arose from the cervical segments of the spinal cord of the AGR by means of dorsal and ventral roots which merged lateral to the spinal cord to form spinal nerves. Each cervical spinal nerve divided into a dorsal and ventral ramus just before exiting the intervertebral foramen. The dorsal rami divided into medial and lateral branches distributed on the medial faces of the semispinalis and splenius muscles, respectively. The ventral rami of C1, C2 and a branch from C3 interconnected to form the cervical plexus from which branches were distributed to the M. cleidomstoideus, M. cleidooccipitalis, M. occipitoscapularis, M. omotransversarius and M. trapezius. The ventral rami of C5, C6, C7, C8 and T1 (first thoracic spinal nerve) interconnected to form the brachial plexus. The cervical spinal nerves gave rise to dorsal rami or primary branches that supplied the skin and muscles of the dorsal part of the neck and the ventral primary branches which interconnected to give rise to the cervical plexus and brachial plexuses of the AGR.

Lower Respiratory System of Sokoto goat Nzalak et al.

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