The behaviour of liver glycogen in experimental animals: I. Methods: the effect of ether and amytal

Charles Arthur Lovatt Evans, 1884-1968

Charles Lovatt Evans, Emeritus Professor of Physiology, University of London, and a former Vice-President of the Royal Society, died on 29 August 1968, at the age of 84, at his home at Winterslow, near Salisbury. He was the foremost pupil and a lifelong associate of E. H. Starling, Jodrell Professor of Physiology at University College London, and eventually occupied the same chair. Lovatt Evans was born in Birmingham and spent the whole of his childhood and early manhood there. His father Charles Evans taught music— piano and violin—and was a man of many interests, of which ancient history was one, and he started to learn Greek when in his sixties. Although a humorist he had somewhat rigid views on religion, life and death, and held the view that the more you do for people the less they do for themselves, so Lovatt Evans was largely left to himself to decide upon his future and surmount the difficulties of finding ways and means. His mother seemed to him to be of rather an aloof nature, spending much of her time in intellectual pursuits often at the expense of her domestic duties. The result was that in his home life he was lonely.

The forebrain is not essential for sympathoadrenal hyperglycemic response to glucoprivation

The reduction of glycolysis by hypoglycemia or the glucose analog 2-deoxy-D-glucose (2DG) stimulates compensatory sympathetic alterations of metabolism. Considerable attention has been focused on the hypothalamus as the probable locus of requisite metabolic signal detection. We report, however, that unanesthetized chronically decerebrate rats are capable of exhibiting sympathoadrenal hyperglycemia in response to the metabolic challenge presented by 2DG. This findings demonstrates that the forebrain is not necessary for glucoprivic stimulation of this reflex. Since cervical cord transection has been shown to eliminate hyperglycemia induced by 2DG, we conclude that the caudal brainstem contains an essential part of the neural mechanism which both detects metabolic need and ameliorates that need through the release of stored fuels.

Anesthesia and the golgi apparatus: enzyme activity changes in a golgi-rich fraction of rat liver after a short ether anesthesia

Activity changes of enzymes in isolated rat liver Golgi preparations at different times (1-48 h) after a short ether anesthesia are reported. Activity of galactosyl-transferase showed a slight gradual increase but thiamine pyrophosphatase decreased sharply, and after 24 h increased to above control level. Arylsulphatase-A remained largely unchanged, and B was significantly decreased. Acid phosphatase activity did remain at the control level, but alkali phosphatase showed a gradual and highly significant increase. Five other enzymes representing probable contaminations from other subcellular organelles, have also been assayed. Correlation is sought between the enzyme activity changes and some other metabolic effects of anesthesia.

The glycogenolytic response to stimulation of the splanchnic nerves in adrenalectomized calves, sheep, dogs, cats and pigs

1. The effects of stimulation of the peripheral ends of one or both splanchnic nerves have been investigated in calves, sheep, dogs, cats and pigs after removal of both adrenal glands.2. Stimulation of both splanchnic nerves produced comparable hyperglycaemic and glycogenolytic effects in sheep, dogs and cats; the mean liver glycogen concentration was reduced by between 7.0 and 10.5 mg/g, five min after stimulation was discontinued, at which time the mean plasma glucose concentration had risen by between 126 and 137 mg/100 ml.3. In five 3-5 week-old calves which were tested under identical conditions the mean liver glycogen concentration was reduced by 13.3 +/- 1.9 mg/g and the plasma glucose concentration raised by 216 +/- 1.9 mg/100 ml., 5 min after stimulation was terminated.4. In pigs, stimulation of both splanchnic nerves invariably produced a rise in the plasma glucose concentration, even when the concentration of glycogen in the liver was less than 5 mg/g before stimulation. The response was, nevertheless, considerably smaller in these animals than in any of the other species investigated.5. Splanchnic nerve stimulation also caused a rise in mean aortic blood pressure and blood haematocrit during the period of stimulation; changes of approximately the same order of magnitude were encountered in all five species.6. Dogs were found to resemble calves in that the hyperglycaemic response to stimulation of a single splanchnic nerve did not differ significantly from that obtained when both were stimulated simultaneously; furthermore, either nerve was found to be equally effective.7. In cats the change in plasma glucose concentration in response to stimulation of a single splanchnic nerve was always less than that which occurred in response to bilateral stimulation although comparable changes in blood haematocrit occurred in both groups of animals.8. It is concluded that stimulation of the splanchnic nerves causes break-down of glycogen in the livers of various unrelated species of adult animals but that the magnitude of the hyperglycaemic response in the young calf provides further evidence of the importance of the sympathetic system in the control of metabolism in the young animal.