Date of Award
Master of Arts
Dr. Jean M. Lawrence
Dr. Jack S. Wood
Dr. Imy V. Holt
Masters Thesis-Open Access
The presence of neurosecretory cells in the suprapharyngeal ganglia of Lumbricus terrestris has been well established (B. and E. Scharrer, 1937). Since these cells may well be the only source of hormones in this organism (B. Scharrer, 1959), the question arises as to their role in the animal's regulation of metabolism The particular aspect of this problem investigated here concerns the effect of these neurosecretory substances on the blood glucose levels in L. terrestris.
Preliminary studies by this investigator on glucose levels in earthworms revealed that blood samples of approximately 15 microliters could be obtained from each animal and the glucose levels were very low. This made it necessary to develop an accurate method for determining micro amounts of glucose in ultra-micro samples of blood. It was decided to use a modification of the orthodianisidine enzymatic method (Glucostat, Worthington Biochemical Corp., Freehold, N. J.) due to its specificity in measuring only beta-D-glucose and not other reducing substances. This method could prove useful to other investigators in studying glucose levels in animals, especially where blood samples of several animals could be pooled and then analyzed.
The second aspect of this study was establishing glucose levels in earthworms after specific treatment of varying environmental conditions, worms that had been slit and decerebrated worms over a period of days.
Thirdly, the effect of the neurosecretory substances from the suprapharyngeal ganglia on glucose levels in earthworms was further studied by decerebrating worms, injecting homogenates of cerebral ganglia and then measuring the glucose levels.
Craig, Joan VanderPol, "The Effect of Neurosecretions from the Cerebral Ganglia on Blood Glucose Levels in Lumbricus Terrestris" (1966). Masters Theses. 4513.