Pyloric caeca

Herring Clupea harengus 170 liver, pyloric caeca 1.08... 

Fig. 10.6.2 The pempherid fish Parapriacanthus ransonneti dissected to show the pyloric caeca and portions of the visceral organs, photographed by daylight (top) and by ultraviolet light (bottom). The strong yellowish fluorescence in ultraviolet light is due to the presence of a large amount of Cypridina luciferin in the pyloric caeca and portions of the intestine. From Haneda and Johnson, 1962.

Starfish, Luidia clathrats, Tampa Bay, Florida vs. Gulf of Mexico 1992 Body wall Pyloric caeca... 

Adult females 240 Increased steroid metabolism in pyloric caeca after 21 days 47... 

Fed diet containing 424 ng2,3,7,8-TCDD/kg ration for 13 weeks, then fed clean diet for another 13 weeks No overt signs of toxicity. After 13 weeks, 78% of the total 2,3,7,8-TCDD was in carcass and visceral fat, and the rest in liver (9%), gill (5%), skin (3%), muscle (2%), and Gl tract, pyloric caeca, kidney, spleen, and heart. At least 96% of the 2,3,7,8-TCDD was not metabolized however, gall bladder bile had 4 TCDD metabolites. The half-time persistence for 2,3,7,8-TCDD in whole body was 18 weeks, and for individual organs 6-19 weeks 18... 

In contrast, 0.01 ppm DDT in water was rapidly absorbed and accumulated by yearling rainbow trout, the bioaccumulation ratio of total DDT as sum of DDT, DDE and TDE being 2700 after 14 days. The highest content was encountered in intestine (76.8 ppm), followed by stomach (46.0 ppm) and pyloric caeca (29.8 ppm). 

Thermal Stability. Increased catalytic efficiency at low temperatures is associated often with a decrease in thermal stability (41). Proteolytic enzymes from the pyloric caeca of cod, herring, and mackerel are more heat labile than bovine trypsin (42) the thyroid protease of burbot from cold waters had lower thermal stability than that from burbot in a warmer habitat (43). The half-life of myofibrillar ATPase at 37°C averages 1 min for the enzyme from Antarctic Ocean fish species, 70 min for the enzyme from fish species in the Indian Ocean, and 600 min for the enzyme from East African hot spring fish (33). 

Thermal Stability. The temperature optimum for arctic cod pepsin is approximately 32°C see Table III) and the enzyme is unstable when incubated at temperatures above 37°C see Figure 4) in contrast to porcine pepsin which has a temperature optimum of approximately 47°C and is unstable at temperatures above 50°C see Figure 4). Accordingly, there is a difference in thermal stability of approximately 13°C for the two enzymes. Similar differences in temperature optima were observed when Greenland cod and American smelt were compared with PP see Table III). These data are consistent with previous reports for intracellular enzymes and for crude preparations of pyloric caeca enzymes from other low-temperature-adapted organisms (42). 

Additionally, the disposition of another AP, 14C-4-fcrf-OP, was investigated in two detailed studies conducted in rainbow trout24 and rudd56 (Scardinius erythrophthal-mus). After 10 days of waterborne exposure to 4 /xg/1 A-tert-OV, the concentration of residues in rainbow trout was the highest in bile, followed by feces, pyloric caeca, liver and intestine. The apparent bioconcentration factors for liver and muscle were 1020 and 101, respectively. In similar experimental conditions, the majority of radioactivity in rudd was recovered in bile and liver. No data were presented on the amount of residues in pyloric caeca, intestine and feces. When fish were transferred to clean water for 8 days, residue levels in bile and liver were reduced by at least 99 and 81%, respectively. 

The pyloric caeca of fish, which have a function similar to that of mammalian pancreas, are a potent source of tryptic enzymes. The crude enzyme preparations made by acetone drying of the comminuted caeca are as effective as commercial proteolytic preparations (Tarr, 1948). According to Kashiwada (1952), this proteolytic enzyme activity rises in spring and decreases gradually in summer in the case of skipjack Katsuwonus Vagans), Crude preparations from redfish (Sebastes marinus) have been studied by Stern and Lockaert (1953), who have determined their optimal conditions of activity and have shown that this activity also compares favorably with that of commercial preparations. 

Kishimura, K, Ojima, T., Tanaka, H., Hayashi, K., and Nishita, K., 2000, Amino acid sequence of phospholipase A2 from the pyloric caeca of starfish Asterina pectinifera. Fisheries Sci., 66, 104. 

Fluorometric BPH activity in pyloric caeca microsomes of A. rubens required NADPH and was inhibited by inhibitors of mammalian cytochromes P-450... 

SKF-525A, metyrapone, ellipticine, clotrimazole), indicating that the reaction is cytochrome P-450-mediated (Den Besten and Livingstone 1989). Steroid metabolism has been extensively studied in echinoderms and cytochrome P-450-mediated reactions are indicated, e.g. hydroxylation of progesterone to 17a-hy-droxyprogesterone in pyloric caeca (600 g supernatant) of A. rubens (Voogt et al. 

Van der Plas AJ, Voogt PA (1983) Histochemical observations on the pyloric caeca of Asterias rubens (Echinodermata, Asteroidea) in relation to the reproductive cycle. J Morphol 178 179-186 Van Dyke RA, Baker MT, Jansson I, Schenkman J (1988) Reductive metabolism of halothane by purified cytochrome P-450. Biochem Pharmacol 37 2357-2361 Varanasi U, Malins DC (1977) Metabolism of petroleum hydrocarbons accumulation and biotransformation in marine organisms. In Malins DC (ed) Effects of petroleum on arctic and subarctic marine environments and organisms, Vol 2 Biological effects. Academic Press, New York, pp 175-270... 

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