Experimental researches regarding the metabolic changes determined by the prolonged exposure to light or by keeping in darkness.

The authors conducted complex investigations in the domain of the intermediary metabolism under experimental conditions on 24 dogs grouped into three lots: lot A, twelve dogs, exposed for six months to the action of continuous light; lot B, six dogs, maintained in darkness; lot C, six dogs, maintained for the same period in the animal house, getting the same food as the other two lots, which are the control lot. We determined some biochemical, hematological, enzymatical parameters, before the beginning of the experiment, and after 24 hours, 48 hours, 7, 14 and 21 days, one, two, three, six months. Then the animals were sacrificed, and fragments from the aorta, coronary vessels, myocardium, brain, adrenals, pancreas and liver were examined both on the optical and on the electronic microscope and we analysed some fats from the vascular tissues.