Abstract
Variation of galactose, glucose, lactate, pyruvate, NEFA and IRI in blood during galactose loading test was investigated in this study.
Oral galactose loading test was examined for 40 patients with diabetes mellitus, 40 with liver diseases and 20 normal subjects. Galactose in blood was measured by the method using galactose dehydrogenase. Furthermore, the galactose loading test by intravenous administration (TengstrOm) was also investigated for 5 patients with liver diseases and 5 normal subjects. The data were explained in accordance with the criteria of judgement reported previously.
About 70 % of the patients with liver diseases and about 40 % of those with diabetes mellitus were shown to be abnormal in the oral galactose loading test. Degree of abnormality was more remarkable in liver cirrhosis. Blood glucose level in the normal subjects slightly increased by galactose loading and returned to the initial level after 2 hours, but in the patients with diabetes mellitus and liver diseases, the increase in blood glucose level continued for a long time. And proportion of increase was the most marked in the diabetic patients. NEFA level in blood decreased not in relation to blood galactose level in all the cases of normal subjects, diabetes mellitus and liver diseases.
The changes of IRI in blood that are usually observed during glucose loading test were not proved to take place in loading of galactose by both oral and venous administration. It was thought that release of insulin by galactose was not marked.
It seems that redox state of NAD and NADH in liver takes part in galactose metabolism. In this study, lactate, pyruvate and lactate/pyruvate in blood were examined with a view to studying in some way the redox state of liver cytoplasma. Normal groups for galactose loading test showed a transient increase of lactate and also elevation of lactate/pyruvate. On the other hand, in abnormal groups of the loading test, increase of lactate was not marked and lactate/pyruvate was also indefinite. It may be said that galactose loading test was advisable to clarify the function of co-enzyme level in liver cytoplasma.
By galactose loading test, an abnormal result was obtained not only in liver diseases but also in diabetes mellitus, and changes of some other substances for carbohydrate metabolism in blood were observed. From this viewpoint, it will be certain that NAD and NADH in liver cell take part in galactose metabolism.
