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Biomedical subjects

J D Few

Publications and source records attributed to J D Few.

49 records · Page 3Linked to original sources
PubMed1969

Stimulation of adrenal glucocorticoid secretion in man by raising the body temperature.

1. Plasma cortisol and corticosterone concentrations increased significantly in eleven resting, unacclimatized subjects after 2 hr exposure to an ambient temperature of 46 degrees C dry bulb, 36 degrees C wet bulb and in two subjects investigated by controlled elevation of body temperature in a hyperthermia test-bed.2. In the same experiments the urinary excretion of 17-hydroxycorticosteroids (17-OHCS) estimated as the 11-oxy and 11-deoxy fractions did not differ significantly in hot and in control conditions.3. Following an initial fall in plasma cortisol concentration during the first hour of heat exposure, cortisol levels increased in the second hour when body temperatures exceeded a ;critical' level of 38.3 degrees C. Two acclimatized subjects did not attain this body temperature even after 2 hr heating and showed no increase in plasma glucocorticoid levels.4. Sweat collected in arm bags, or by suction, in controlled hyperthermia experiments contained negligible amounts of cortisol (0.34-1.70 mug/100 ml. sweat).5. Changes in plasma cortisol specific activity after intravenous injection of 1,2[(3)H]cortisol indicated that the raised plasma concentration was brought about by increased adrenal secretion, though this was accompanied by more rapid removal of cortisol from the circulation in hot conditions. Excretion of tritium by the kidney was not significantly altered. It was not possible to determine whether changes in liver function contributed to the elevation of the plasma cortisol level but it was found that a larger proportion of cortisol was oxidized to cortisone, or to a metabolite closely resembling cortisone, in the heat.

17-Hydroxycorticosteroids↗
PubMedDate not supplied

The effect of cortisol or ACTH on plasma concentrations of free fatty acids.

The effect of infusion of cortisol (14 mumol) or ACTH (Synacthen, 250 micrograms) injection on plasma levels of free fatty acids has been examined in normal men. The increment in plasma cortisol levels after infusion of cortisol (+182%) was much less than after ACTH injection (up to 262%). Mean plasma levels of free fatty acids were only significantly increased after ACTH injection. However, some inter-subject variation occurred and a small but significant increment in plasma levels of free fatty acids was seen for one control subject and for a subject who received an infusion of cortisol. It is possible that the reported diurnal variations in plasma levels of free fatty acids may be related to changes in plasma levels of ACTH or cortisol throughout a 24h period.

Adult↗