To detect distribution and relative frequency of diffuse neuroendocrine system （DNES） cells in the gastrointestinal tract of channel catfish （lctalurus punctatus）, the intestinal tract of channel catfish was divid...To detect distribution and relative frequency of diffuse neuroendocrine system （DNES） cells in the gastrointestinal tract of channel catfish （lctalurus punctatus）, the intestinal tract of channel catfish was divided into seven portions from proximal to distal： the enlarged area after oesophagus, cardia, fundus, pylorus, and anterior, middle, and posterior intestine. Immunohistochemical method using the strept avidin-biotin-complex （SABC） was employed. All antisera between seven portions of the channel catfish were compared statistically using statistical package for the social science （SPSS）. Five types of DNES ceils were determined： neuropeptide Y-immunoreactive （NPY-IR） cells were demonstrated in both anterior and middle intestine; serotonin （5-HT） immunoreactive cells were detected throughout the whole gastrointestinal tract; vasoactive intestinal peptide （VIP） positive cells were at the highest frequency in pylorus; glucagon-immunoreactive （GLU-IR） cells were moderate in number in the fundus and anterior, middle intestine, and no immunoreactivity was determined in the other portions; somatostatin （SOM） positive cells were more abundant in the anterior and middle intestine. The regional distribution and relative frequency of immunoreactive cells in the channel catfish, Ictalurus punctatus, are essentially similar to those of other fish. However, some characteristics are observed in this species, which further proved that the diversity of the physiological function of DNES cells was based on their morphology.展开更多
The objectives of this study were as follows: 1) to establish a baseline ethoxyresorufin-O-deethylase (EROD) activity level in channel catfish (Ictalurus punctatus), 2) to assess changes in induction of cytochrome P45...The objectives of this study were as follows: 1) to establish a baseline ethoxyresorufin-O-deethylase (EROD) activity level in channel catfish (Ictalurus punctatus), 2) to assess changes in induction of cytochrome P450 enzyme in channel catfish following exposure to creek water at the discharge point from the Troy (Alabama) Wastewater Treatment Plant (TWWTP) compared to upstream samples from Walnut Creek, 3) to compare EROD activity in populations maintained in laboratory and field settings, and 4) to quantify cytochrome P450 gene expression. Enzyme activity was measured fluorometrically and CYP1 gene expression was analyzed by quantitative real-time reverse transcription polymerase chain reaction. A mean EROD baseline was established at 0.03 nmol/min/μg of protein. The overall mean field effluent (TF) EROD had a significant 5-fold increase over field upstream (UF) exposed catfish;and overall mean laboratory effluent (TL) exposed catfish EROD had a significant 1.8-fold increase over laboratory upstream (UL) exposed catfish. Field exposures generally showed more robust enzyme induction over laboratory exposures on all sampling days. Ex- pression of the CYP1B gene following TF exposure was 6-fold over UF. Results suggested that in situ exposure to wastewater pollutants using caged test organisms provided a much more sensitive local monitor of pollutant exposure and biological impact than ex situ toxicological studies.展开更多
PBDEs are widely used brominated flame retardant, which are increasingly reported in the environment. Concentrations of thirteen PBDEs in a large number of channel catfish and fish feeds collected from Hubei province ...PBDEs are widely used brominated flame retardant, which are increasingly reported in the environment. Concentrations of thirteen PBDEs in a large number of channel catfish and fish feeds collected from Hubei province of China were investigated in this study. A fast isotopic dilution GC-MS method was firstly developed to simultaneously determine thirteen PBDEs in channel catfish and fish feeds in this study, and especially for the first time PBDEs in fish feeds. Pressurized liquid extraction and multi-layer silica gel column chromatography cleanup were used, some important steps and crucial parameters were modified and intensified compared with other literatures, and GC and MS conditions were optimized. The limits of quantitation values of 0.25 - 5 μg·kg-1 wet weight in channel catfish were calculated for PBDEs;so did 1 - 20 μg·kg-1 wet weight in fish feeds. In addition, good repeatability and accuracy of the whole method were achieved. The established methods were therefore suitable for the simultaneous determinations of thirteen PBDEs in these samples at trace contamination levels. Using the established methods, PBDEs emerged in 10 of 180 channel catfish and 13 of 115 fish feeds, and the dominant PBDEs homologues were PBDE-28, PBDE-47, PBDE-100, PBDE-99, PBDE-154, PBDE-153 and PBDE-183. The detection rates of seven PBDEs congeners were in turn respectively 1.74%, 7.83%, 4.35%, 5.22%, 3.48%, 2.61% and 2.61% in fish feeds, and detection rates of seven PBDEs congeners were in turn respectively 1.11%, 3.89%, 2.22%, 1.67%, 1.11%, 1.11% and 1.11% in channel catfish. There was significant correlation in PBDEs between matching channel catfish and fish feeds (R2 = 0.742, P < 0.001, n = 30), suggesting that fish feeds contaminated with PBDEs possibly resulted in PBDEs residual in channel catfish through biological transfer.展开更多
基金supported by the Special Founda-tion for Young Leaders Fellowship in the Sichuan Agri-cultural University, China (45078925-5).
文摘To detect distribution and relative frequency of diffuse neuroendocrine system （DNES） cells in the gastrointestinal tract of channel catfish （lctalurus punctatus）, the intestinal tract of channel catfish was divided into seven portions from proximal to distal： the enlarged area after oesophagus, cardia, fundus, pylorus, and anterior, middle, and posterior intestine. Immunohistochemical method using the strept avidin-biotin-complex （SABC） was employed. All antisera between seven portions of the channel catfish were compared statistically using statistical package for the social science （SPSS）. Five types of DNES ceils were determined： neuropeptide Y-immunoreactive （NPY-IR） cells were demonstrated in both anterior and middle intestine; serotonin （5-HT） immunoreactive cells were detected throughout the whole gastrointestinal tract; vasoactive intestinal peptide （VIP） positive cells were at the highest frequency in pylorus; glucagon-immunoreactive （GLU-IR） cells were moderate in number in the fundus and anterior, middle intestine, and no immunoreactivity was determined in the other portions; somatostatin （SOM） positive cells were more abundant in the anterior and middle intestine. The regional distribution and relative frequency of immunoreactive cells in the channel catfish, Ictalurus punctatus, are essentially similar to those of other fish. However, some characteristics are observed in this species, which further proved that the diversity of the physiological function of DNES cells was based on their morphology.
文摘The objectives of this study were as follows: 1) to establish a baseline ethoxyresorufin-O-deethylase (EROD) activity level in channel catfish (Ictalurus punctatus), 2) to assess changes in induction of cytochrome P450 enzyme in channel catfish following exposure to creek water at the discharge point from the Troy (Alabama) Wastewater Treatment Plant (TWWTP) compared to upstream samples from Walnut Creek, 3) to compare EROD activity in populations maintained in laboratory and field settings, and 4) to quantify cytochrome P450 gene expression. Enzyme activity was measured fluorometrically and CYP1 gene expression was analyzed by quantitative real-time reverse transcription polymerase chain reaction. A mean EROD baseline was established at 0.03 nmol/min/μg of protein. The overall mean field effluent (TF) EROD had a significant 5-fold increase over field upstream (UF) exposed catfish;and overall mean laboratory effluent (TL) exposed catfish EROD had a significant 1.8-fold increase over laboratory upstream (UL) exposed catfish. Field exposures generally showed more robust enzyme induction over laboratory exposures on all sampling days. Ex- pression of the CYP1B gene following TF exposure was 6-fold over UF. Results suggested that in situ exposure to wastewater pollutants using caged test organisms provided a much more sensitive local monitor of pollutant exposure and biological impact than ex situ toxicological studies.
文摘PBDEs are widely used brominated flame retardant, which are increasingly reported in the environment. Concentrations of thirteen PBDEs in a large number of channel catfish and fish feeds collected from Hubei province of China were investigated in this study. A fast isotopic dilution GC-MS method was firstly developed to simultaneously determine thirteen PBDEs in channel catfish and fish feeds in this study, and especially for the first time PBDEs in fish feeds. Pressurized liquid extraction and multi-layer silica gel column chromatography cleanup were used, some important steps and crucial parameters were modified and intensified compared with other literatures, and GC and MS conditions were optimized. The limits of quantitation values of 0.25 - 5 μg·kg-1 wet weight in channel catfish were calculated for PBDEs;so did 1 - 20 μg·kg-1 wet weight in fish feeds. In addition, good repeatability and accuracy of the whole method were achieved. The established methods were therefore suitable for the simultaneous determinations of thirteen PBDEs in these samples at trace contamination levels. Using the established methods, PBDEs emerged in 10 of 180 channel catfish and 13 of 115 fish feeds, and the dominant PBDEs homologues were PBDE-28, PBDE-47, PBDE-100, PBDE-99, PBDE-154, PBDE-153 and PBDE-183. The detection rates of seven PBDEs congeners were in turn respectively 1.74%, 7.83%, 4.35%, 5.22%, 3.48%, 2.61% and 2.61% in fish feeds, and detection rates of seven PBDEs congeners were in turn respectively 1.11%, 3.89%, 2.22%, 1.67%, 1.11%, 1.11% and 1.11% in channel catfish. There was significant correlation in PBDEs between matching channel catfish and fish feeds (R2 = 0.742, P < 0.001, n = 30), suggesting that fish feeds contaminated with PBDEs possibly resulted in PBDEs residual in channel catfish through biological transfer.
