RESUMEN
Bisphenol A [BPA], an industrially chemical compound, is abundantly used as a primary raw material for production of polycarbonate plastics, epoxy resins and many industrial productions. To show the effect of BPA on plasma steroid hormone variations, male Yellowfin seabream were subjected to this compound. Fish were intraperitonealy injected by dissolved BPA in coconut oil [10, 50, 100 and 150 microg/g-1 week-1] of over 2 weeks. Plasma samples were collected on days 0, 7 and 14. Plasma levels of steroid hormones [testosterone and 17beta-estradiol] were determined by radioimmunoassay. Plasma levels of 17beta-estradiol hormone in BPA treated fish was significantly increased in a dose dependent manner, after 7 and 14 days of exposure [p<0.05]. Plasma levels of testosterone showed decrease in response to different concentrations of BPA. However this decrease in testosterone levels was significant only in response to 100 and 150 micrograms per gram of BPA. It can be concluded that short term exposure of Yellowfin seabream [Acanthopagrus latus] to BPA can make destructive effects in reproductive system
RESUMEN
Alterations to mitochondria-rich cells [MRC] in the fish gill epithelium have been previously reported. To specify the variation pattern of apical openings in mitochondria- rich cells in short and long terms exposure to different salinities. Yellowfin seabream, [Acanthopagrus latus] was subjected to different salinities [freshwater, 5, 20 and 60 ppt] besides the normal environmental salinity in the Musa creek [42 ppt] over 21days, with three replicates for each condition. Samples were collected at the 1[st], 7[th] and 21[st] days of experiment. Dissected gill arches were fixed in 2% glutaraldehyde+2% paraformaldehyde [pH=7.4] at 4°C and studied using scanning electron microscopy. Three subtypes of mitochondria-rich cells [shallow basin, deep hole and wavy convex] were detected in the gill epithelium based on different environmental salinities. While most of mitochondria-rich cells were present in seawater group, all of them were detected as the shallow basin subtype in 60 ppt group. Meanwhile, decrease in salinity to 20 ppt, made morphological changes in the apical membrane of the mitochondria-rich cells on day 7, so that most of these cells have been detected as wavy convex or shallow basin subtypes. On the other hand, on day 21 they showed a pattern similar to the basal status. Furthermore, when they were transferred to hypoosmotic medium [5 ppt and FW], rapid changes were exhibited in the apical membrane of mitochondria-rich cell which were stabilized after 21 days so that all subtypes of mitochondria-rich cells were observed in photomicrographs of gill filaments. Shallow basin mitochondria-rich cells as typical cells in seawater fish species, would be able to do osmoregulation in hyperosmotic environment in yellowfin seabream, yet in hypoosmotic conditions all sub- types of the mitochondria-rich cells would be required