Distribution of glucose in the spiny dogfish ( [formula omitted]) and the brier skate ( [formula omitted

Abstract

The distribution of glucose between blood and cerebrospinal fluid (CSF) has previously been studied in mammals (1–4). It has been observed that CSF and blood glucose concentrations correspond closely when fairly steady blood glucose levels are maintained. However, when these are altered, the corresponding changes in CSF glucose concentrations have been shown to log behind (2,3). It has thus been assumed that an active transport mechanism is concerned with regulating CSF glucose concentration (3). There have not been any observations as to the distribution of glucose between CSF and blood in the elasmobranch fishes. We therefore, wish to report studies of glucose distribution between plasma, CSF (here called ventricular fluid), extradural fluid (EDF) and pericardial fluid (PCF) in the spiny dogfish ( Squalus acanthias ) during normal and elevated blood glucose levels. Ventricular fluid (VF) and plasma glucose concentrations were also measured in the brier skate ( Raja eglanteria ).