Brain Acetylcholinesterase (AChe) activity and Melanomacropage Centers (MMCs) formation in nile tilapia (Oreochromisniloticus Linn.) as indicators of exposure to carbaryl.

Date

4-2002

Degree

Bachelor of Science in Biology

Major Course

Major in Zoology

College

College of Arts and Sciences (CAS)

Adviser/Committee Chair

Pablo P. Ocampo

Abstract

This study aimed to determine the effects of residual carbaryl (carbamate) concentration on relative organ weights, brain acetylcholinesterase (AChE) activity, and melanomacrophage centers (MMCs) formation in Nile tilapia (Oreochromis niloticus). Sixty male juvenile Nile tilapia were subjected to different residual treatments of carbaryl for 15 days. Individual test fish were randomly assigned under four treatment groups including the control, A-0.070, B-0.196, and C-0.223 pg/L treatments, each containing 15 fish. After cessation of treatment, each fish was decapitated and the brain, liver, spleen, and gonads were collected. Relative weights of the liver, spleen and gonads were determined. Acetylcholinesterase (AChE) activity was measured colorometrically. Melanomacrophage centers (MMCs) formation was observed and measured in liver and spleen tissues. Results show that the varying concentrations of carbaryl have effect on body weights and relative weights of the selected organs. The activity of AChE measured were 2.01, 3.10, 1.39, 3.78 in moles of substrate hydrolyzed per minute per gram of tissue for control, 0.070, 0.196, and 0.223 ug/L doses, respectively. Inhibition of the enzyme was observed only among individuals under 0.196 ug/L concentration level. Histological analysis revealed that the mean MMC's size recorded among treated O. niloticus liver were 220.32, 300.672 and 681.696 um2 for 0.070, 0.196, and 0.223 ug/L. treatments. respectively, thus showing a dose dependent response. The values on the liver MMC's size of the treated fish were statistically different with those exhibited by the control (p<0.05) However, The MMC's size recorded for spleen samples were 15347.23, 16224.62, and 12 791.52 um2 for 0.070, 0.196, and 0.223 ug/L treatment, respectively, Spleen samples seen to be not influenced by the treatments. O. niloticus was considered a potential bio-indicator model based on the bio-indices used in the study.

Language

English

Location

UPLB Main Library Special Collections Section (USCS)

Call Number

Thesis

Document Type

Thesis

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