Effect of water immersion on renin-aldosterone and renal handling in normal man

Page 368: M. Epstein and T. Saruta. “Effect of water immersion on renin-aldosterone and renal handling in normal man.” Page 368: line 10, first paragraph of materials and methods, column 2, should begin: excretory rates....

Renal vascular response to salt restriction in normal man. Evidence against adrenergic mediation

The role of the sympathetic nervous system in the renal vasoconstriction induced by sodium restriction has been assessed in normal man in balance on a 10-mEq sodium intake. Renal blood flow was measured with radioxenon injected into the renal artery. Phentolamine infused into the renal artery at rates of up to 3 mg/min did not increase net renal perfusion or alter its intrarenal pattern. That dose of phentolamine was at least 30 times the threshold for significant blockade of the renal vascular effects of a large dose of epinephrine injected intra-arterially. The results suggest strongly that neither circulating catecholamines nor the sympathetic nerves play a central role in the renal vascular response to salt restriction in normal man.

Metabolic studies of isolated human eccrine sweat glands

This paper describes a method for isolating and studying the metabolism of human eccrine sweat glands. (a) Electron microscopy of glands which had been isolated and then incubated for an hour revealed no apparent alteration in morphology. (b) Known variation in gland size (male > female > children) was reflected in the relative rates of lactate production. (c) Lactate production was approximately 1.5 nmoles/gland per hr in the absence of glucose and rose to 2.7 at physiological concentrations of glucose (5.6 mmoles/liter). This amount of lactate production agrees well with the amounts found in sweat. (d) Both adrenergic (epinephrine) and cholinergic (methacholine) stimuli increased lactate production. (e) Glycogen depletion was demonstrated during incubation. (f) O(2) consumption was measured and aerobic metabolism was found to account for less than 1% of the energy derived from anaerobic pathways. These studies demonstrate that the large amounts of lactate appearing in human eccrine sweat can be accounted for by glandular metabolism and that both glycogen and glucose can be used as substrates.

Diabetic amyotrophy. Light and electron microscopic investigation

An elderly male with recent onset of mild diabetes mellitus developed diabetic amyotrophy. There were muscle atrophy and pain in the thighs without sensory changes. Multiple biopsies were made over a fourteen-month period and studied with light and electron microscopy. The changes of individual muscle fiber atrophy, typical of this disease, are described.