BACKGROUND: Free cyanide is a potent toxic agent in the aquatic environment.  Freshwater fish are the most cyanide-sensitive group with high mortality at free cyanide concentrations above 20 μg/L. Exposure to cyanide ions can cause stress, increased mortality and place an appreciable metabolic load on fishes. Rhodanese is a ubiquitous mitochondrial enzyme in both prokaryotes and eukaryotes that detoxifies cyanide (CN-) by converting it to thiocyanate (SCN). OBJECTIVES: The purpose of this investigation was to determine and compare the pattern of tissue distribution of Rhodanese in different tissues of four native Barbus fish including Mesopotamichthys sharpey, Tor grypus, Luciobarbus xanthopterus and Luciobarbus barbulus. METHODS: Fishes (10 from each species) with length of 32.5 ± 6.5 and weight of 440 ± 110   were collected from five major fishing reservoirs of Karoun River including Gotvand, Shushtar, Molasani, Darkhoine and Ahvaz. Rhodanese activity was assayed by the method of Sorbo in the liver, kidney, gill and intestine. The unit of enzyme activity was defined as micromoles thiocyanate formed per minute at 37 °C and pH 9.2 and enzyme activity was expressed as U/mg protein. RESULTS: Rhodanese activity was detected in all tissues studied, albeit in different amounts. Specific activities of Rhodanese (U/mg protein) in different tissues ranged from 0.135 to 0.337 in the liver, 0.113 to 0.262 in the kidney, 0.121 to 0.157 in the gill, and 0.094 to 0.162 in the intestine, respectively. CONCLUSIONS: The highest activity of Rhodanese in all four species was observed in the liver and kidney, followed by the gill and intestine. Our results suggest that Rhodanese may be functional in many physiological activities in these species which needs to be clarified in detailed.

BACKGROUND: Safflower plant can be used in fish due to its antioxidant properties. In the present study, the side effects of intraperitoneal injection of safflower extract in rainbow trout have been investigated. OBJECTIVES: The effect of the intraperitoneal injection of Safflower (Carthamus tinctorius) extract on Aspartate aminotransferase, Alanine aminotransferase and Alkaline phosphatase as tissue damage indicators and also the histopathologic analysis of kidney and liver tissues in rainbow trout (Oncorhynchus mykiss) have been investigated. METHODS: To this end, rainbow trout with an average weight of 100 ±5 gr were supplied and intraperitoneally injected with different levels of Safflower extract. In this regard, one negative control group (with no injection), one positive control group (injected with 0.2 ml normal saline) and three treatment groups (injected with 50, 100 and 200 mg/kgbw of safflower extract, respectively) were considered. Blood samples were taken on the third, seventh and tenth days after injection, in order to isolate blood serums and analyze the ALP, ALATA and ASAT activities. Kidney and liver tissue samples were also taken on the seventh-day post injection. RESULTS: The levels of ALP, ALATA and ASAT activities significantly increased in all treatment groups that received safflower extract compared to control groups in all samples (sig<0.05). In histological analysis typical pathologic effects were recorded in kidney and liver tissue sections. CONCLUSIONS: Intraperitoneal injection of Safflower extract at dosages of 50-200 mg/kgbw led to damage in the liver and kidney tissues, so that the concentration of 200 mg / L had severe histological complications in these tissues. Hence some limitations must be taken into account for using this extract as immune-stimulant or vaccine adjuvant.

BACKGROUND: Cobalt is an essential nutrient for ruminants which is required for the synthesis of vitamin B12 by the ruminal microflora. Cobalt deficiency can lead to a deficiency of vitamin B12, which plays a major role in many metabolic reactions in the body. OBJECTIVES: This study was conducted to evaluate cobalt status in the serum and liver of cattle. METHODS: In different seasons, the blood serum and liver concentration of cobalt in slaughtered cattle in Urmia city were measured by atomic absorption in 151 and 196 cattle, respectively.   RESULTS: The results of cobalt measurement indicated that in 12.6% of serum and 21.4% of liver samples the concentration of cobalt was less than normal range with the Mean ± SD value of 0.64 ± 0.25 µg/dl and 0.15 ± 0.04 µg/gDM, respectively. The seasonal variations of cobalt values were assessed in serum and liver samples and following results were obtained: spring (2.18 ± 1.64 µg/dl, 0.23 ± 0.13 µg/gDM), summer (3.42 ± 1.04 µg/dl, 0.42 ± 0.27 µg/gDM), autumn (3.45 ± 0.37 µg/dl, 0.47 ± 0.38 µg/gDM) and winter (2.75 ± 0.59 µg/dl, 0.35 ± 0.09 µg/gDM). CONCLUSIONS: According to the results of this study, it seems that there is a subclinical deficiency of cobalt in cattle of this region and it is recommended that preventive measures be considered to prevent the complications and disorders caused by its clinical deficiency.

BACKGROUND: The histogenetic study is a useful and practical laboratory method for obtaining basic and effective information in order to reveal the process of histogenesis and development of organs in different stages during the embryonic period. This applied method helps us to understand the formation time of each organ and its tissue structure. OBJECTIVES: The aim of the present study was to study the histogenesis and histochemistry of the pheasant liver during the embryonic period. METHODS: Sixty fertile eggs were placed in the incubator and sampling was performed from day 5 to the end of incubation period. The liver samples were fixed in 10% Buffered Formalin and the slides were stained with Hematoxylin and Eosin (H&amp;E), Periodic Acid Schiff (PAS) and Masson Trichrome (MT). RESULTS: In this study, liver parenchyma, changes in the hepatocytes and their glycogen storage, as well as the appearance time of canaliculi, biliary ducts, central veins and port spaces were investigated. CONCLUSIONS: Differences in the time of the formation of the organs and structures in various birds relate to different incubation period or species variations. In this research, as the first study on the liver histogenesis of the pheasant, the formation of this organ from the fifth day to the end of the fetal period was examined and it was observed that the evolution and tissue development of the liver is completed until the eighteenth day of incubation period.