Fat-mobilizing action of amphetamine.

The effects of amphetamine and methamphetamine on plasma free fatty acid (FFA), blood glucose, serum total fat, and triglyceride concentrations were investigated in 21 subjects; the effect of epinephrine were studied in an identical manner in 14 subjects. The administration of amphetamine and methamphetamine led to an increase in the plasma FFA concentration. No significant changes were found in the blood glucose, serum total fat, and triglyceride concentrations. Kinetic studies of FFA were also made in some of the subjects receiving amphetamine, methamphetamine, and epinephrine. It was shown that amphetamine and methamphetamine lead to an augmentation of plasma FFA pool due to a primary increase of FFA production rate. Catecholamine depletion, by prolonged parenteral adminstration of reserpine, nearly completely abolished the adipokinetic action of amphetamine whereas the effect of epinephrine was greatly potentiated. This was interpreted as evidence for the dependence of the adipokinetic action of amphetamine on endogenous catecholamines. ESTIMATED FROM A DOSE RATIO (AMPHETAMINE: epinephrine) of 352:1, the relative adipokinetic potency of amphetamine, expressed as peak DeltaFFA rise, +DeltaFFA area, and DeltaFFA production rate, respectively, was found to be 55, 84, and 39% in comparison with the same effects of epinephrine. The more pronounced changes in +DeltaFFA area reflect the longer duration of action of amphetamine viz. epinephrine. This study demonstrates that amphetamine is an adipokinetic agent causing an increase in the plasma FFA pool of a lesser extent but of longer duration than equipressor doses of epinephrine. The mechanism of fat-mobilizing action of amphetamine is indirect i.e., dependent on endogenous catecholamine release.

L-dopa, growth hormone and adipokinesis in the lean and the obese.

Fourteen human volunteers (5 lean of both sexes, 4 grossly obese male, 4 grossly obese female, and one patient suffering from hypopituitarism) were given 500 mg of L-dopa orally, and growth hormone (HGH), cortisol, prolactin (hPRL), insulin, FSH, LH, free fatty acids (FFA) and blood glucose were determined up to 300 minutes following the drug. The lean group showed a uniformly marked increase in HGH followed by a significant FFA rise. The obese females exhibited blunted HGH and a somewhat reduced FFA response. In the obese male, there were no HGH und FFA increments. Unstimulated levels of HGH were lower and FFA markedly higher in both obese male and female vs the lean group. The patient with hypopituitarism showed no significant HGH and FFA response. In all groups, hPRL decreased, while Cortisol, LH, FSH, and blood glucose levels remained uninfluenced.

The acute effect of 2-bromo-a-ergocryptine (CB-154) on anterior pituitary hormones and free fatty acids in man.

CB-154 was administered to six healthy subjects in three different single doses - 1 mg, 2,5 mg, and 3 mg. Growth hormone, prolactin, follicle stimulating hormone, luteinizing hormone, cortisol, blood sugar and free fatty acids were determined. 2.5 and 3 mg doses of CB-154 induced a significant rise in growth hormone and free fatty acids, while prolactin decreased. In addition, CB-154 prevented the circadian fall of plasma cortisol. There were no changes in follicle stimulating hormone, luteinizing hormone or blood sugar levels.

Studies of endocrine and affective functions in complex flight manoeuvres.

Endocrine and metabolic changes, as well as affective functions, were studied in eight healthy volunteers anticipating and executing a prearranged sequence of aerobatic flight. Control measurements were made at complete physical and mental rest. The following were determined: anxiety and hostility levels, blood glucose, cholesterol, triglyceride, plasma free fatty acids (FFA), serum thyroxine (T4), corticosteroids, prolactin, growth hormone, immunoreactive insulin and urinary excretion of VMA. The pattern of response was uniform in all subjects. Significant changes were seen in plasma FFA, corticosteroids, growth hormone and immunoreactive insulin following aerobatic flight. Anticipation of flight induced anxiety arousal and significant directional changes in plasma FFA, corticosteroids, as well as in VMA excretion. Hostility scores were highest immediately upon termination of flight.