The utility of a FORTRAN program package, which enables the scientific investigator to make a rapid assessment of laboratory data is described. Data are submitted from the keyboard or specified disk files in the form of coordinate pairs. The program includes routines for plotting values as a series of X-Y pairs on the computer video monitor or for comparing the X and Y arrays via paired differences and Student's t-test. A least squares linear regression of plotted data may also be called. Data modification, curve fitting, and I/O are easily handled in either single pair or column format. Examples of both statistical and graphical data analysis are presented.

Computers↗

PubMedDate not supplied

Hypercapnia and resultant bicarbonate transfer processes in an elasmobranch fish (Scyliorhinus stellaris).

In order to test the effects of hypercapnia on the acid-base status of fish, larger spotted dogfish were exposed to sudden changes of PCO2 in a closed seawater recirculation system. pH, PCO2 and PO2 were determined in arterial blood and seawater. The exchange of bicarbonate between extracellular space (ECS), intracellular space (ICS), and seawater (SW) was obtained from changes of the total bicarbonate amount in ECS and SW. After fourfold increase of PCO2 arterial pH fell markedly, but started to recover immediately towards control values. This was caused by compensatory accumulation of bicarbonate in the ECS. According to the origin of the extracellular bicarbonate increase three periods could be distinguished: 1.-- Bicarbonate transferred from ICS to both ECS and SW; 2. -- Bicarbonate transferred from both SW and ICS to ECS; 3. -- Bicarbonate transferred from SW to both ECS and ICS. After return to normocapnia similar periods occurred with opposite transfer directions and delayed period transitions. In the first period the ICS was found to be the only source for compensatory bicarbonate increases and even in the second period the ICS contributed to compensation of the extracellular pH. Thus bicarbonate exchange with the ICS appears to be an important regulatory mechanism diminishing the extracellular pH variations after changes in PCO2, before other compensatory mechanisms are initiated.

Animals↗