Effects of pre-sampling fasting on serum characteristics of common carp (Cyprinus carpio L.)

Common carp, Cyprinus carpio (L.) were blood-sampled after 0, 2, 6, 12, 24, 48 and 72 h fasting to find serum baseline levels. There was a significant difference in serum glucose, lactate, triglyceride and total protein but not cholesterol, albumin and calcium levels among the treatments. Glucose levels increased with fasting tine and reached to a peak after 6 h. Then, the glucose level decreased to the lowest level after 12 h. Changes of glucose and lactate had reverse trends, as lactate levels decreased with fasting time and reached to the dip point at 6 h and, thereafter, the levels increased to peak point at 12 h. Serum glucose and lactate levels showed stable values during 24-72 h of fasting, compared with the values measured at 0 h. Triglyceride levels showed an increasing trend parallel to that of the fasting period and reached to a peak point after 6 h. The levels reached 0 h values at 24 h and showed further decrement at 48 and 72h. Total protein showed elevation while fasting progressed and reached the peak point at 6 h and remained stable during 24-48 h fasting; However, it decreased after 72 h fasting. According to the results, cholesterol, calcium and albumin baseline levels were not affected by 0-72 h fasting. Glucose and lactate baseline could be determined after 24-72 h fasting. Total protein baseline could be determined after 24-48 h fasting. Triglyceride levels are significantly affected by fasting period which should be taken into account when it is measured. Possible mechanisms involving in common carp serum fluctuation over 0-72 h fasting period are discussed