Morphological and functional characteristics of pancreas in adult Zebrafish Danio rerio over 12 weeks

摘要

Morphological and stereometric functional changes over time in Zebrafish pancreas are described. Thirty-six zebrafish of 12 groups of 3 adult fish each representing a study week were used. At the end of each week fish were euthanized, pancreas excised and fixed for microphotographic measurement. Graphs of 3 random fields of tissue from each fish/week were used to determine volume density (Vv) of pancreatic acini and islets, adipocytes, and vessels by histologic score and the Delesse principle. Density of acini were 57 ± 11% at 2 weeks compared with 79 ± 10% at 4 weeks, islets ~6.9 ± 6.4% at 7 weeks versus 16.1 ± 17.6% at 1 week and vessels 2.2 ± 3.9% at 5 weeks and 7.4% ± 7.3 at 2 weeks, adipocytes 4.9 ± 6.3% at week 1 and 32.4 ± 15.8% at 2weeks age. Density of acini were significantly different between 1st and 2nd, 2nd and 4th, 2nd and 5th, 2nd and 8th, and 2nd and 10th weeks but the was no difference in density of islets or vessels at any age. Density of adipocytes was significantly different between the 1st and 2nd, 2nd and 4th, and 2nd and 10th weeks. No significant correlation was found between volume density and age but there was a highly significant negative correlation between densities of acini with adipocytes. Volume densitiesof the pancreas of adult zebrafish showed no significant morphological changes over 12 weeks. Further studies to evaluate other pancreatic structures such as connective tissue and different types of collagen present should be pursued.