The Effect of Somatostatin on Metabolic and Hormonal Changes During and After Exercise

Chalmers, R. J.; Bloom, Stephen R.; Duncan, Garfield G.; Johnson, Ralph H.; Sulaiman, W. R.

doi:10.1111/j.1365-2265.1979.tb02101.x

Cited by 15 publications

(9 citation statements)

References 29 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The reduction in glucose concentration that occurred during exercise in the hormonal control groups was not attributable to a direct effect of somatostatin, since hypoglycemia does not develop during exercise in humans when somatostatin is infused without hormonal replacement (16). Also, when no exercise load was imposed on the subjects, normal values for glucose concentration and production were maintained for 4 h. Furthermore, Cherrington and associates (17) have demonstrated that there are minimal direct effects of somatostatin on the metabolism of glucose.…”

Section: Discussionmentioning

confidence: 94%

Role of changes in insulin and glucagon in glucose homeostasis in exercise.

Wolfe¹,

Nadel²,

Shaw³

et al. 1986

J. Clin. Invest.

133

View full text Add to dashboard Cite

This experiment was performed to determine if plasma glucose homeostasis is maintained in normal human volunteers during light exercise (40% maximal oxygen consumption [VO2 Max]) when changes in insulin and glucagon are prevented. Hormonal control was achieved by the infusion of somatostatin, insulin, and glucagon. Glucose kinetics and oxidation rates were determined with stable isotopic tracers of glucose, and by indirect calorimetry. Two different rates of replacement of insulin and glucagon were used; in one group, insulin was clamped at 19.8±2.6 AU/ml (high-insulin group), and in the other group insulin was clamped at 9.2±1.3 jzU/ml (low-insulin group). Glucagon was maintained at 261±16.2 and 124±6.4 pg/ml, respectively, in the high-insulin and low-insulin groups.Without hormonal control, plasma glucose homeostasis was maintained during exercise because the increase in glucose uptake was balanced by a corresponding increase in glucose production. When changes in insulin and glucagon were prevented, plasma glucose concentration fell, particularly in the high-insulin group. Glucose uptake increased to a greater extent than when hormones were not controlled, and glucose production did not increase sufficiently to compensate. The increase in glucose uptake in the hormonal control groups was associated with an increased rate of glucose oxidation. When euglycemia was maintained by glucose infusion in the hormonal control subjects, the modest increase in glucose production that otherwise occurred was prevented.

show abstract

Section: Discussionmentioning

confidence: 94%

Role of changes in insulin and glucagon in glucose homeostasis in exercise.

Wolfe¹,

Nadel²,

Shaw³

et al. 1986

J. Clin. Invest.

133

View full text Add to dashboard Cite

show abstract

“…It is known that central a-1 and a-2 adrenergic stimulation during exercise leads to increased GHRH release, a response which can be abolished by the administration of somatostatin (17) or reduced by adrenergic antagonists such as phentolamine (18,19). Peripheral catecholamines, however, do not appear to influence GH release during exercise since there is a lack of any GH response to infused adrenaline (20).…”

Section: Discussionmentioning

confidence: 99%

Exercise-induced GH secretion is enhanced by the oral ingestion of melatonin in healthy adult male subjects

et al. 1999

View full text Add to dashboard Cite

There is evidence that melatonin may play a role in modulating pituitary secretion, although the mechanisms are unclear. We examined the effects of a single dose of oral melatonin (5 mg) on exerciseinduced GH secretion. In a randomised, double-blind, placebo-controlled study, seven healthy male subjects undertook an initial period of graded bicycle ergometric exercise to determine maximum workload and oxygen uptake (VO 2 max ). Subjects were subsequently studied on two further occasions, receiving either melatonin or placebo in random order at the onset of each study (¹60 min). At 0 min a period of bicycle exercise was performed for 8 min at a workload corresponding to 70 % of that achieved at VO 2 max . Serum GH and IGF-binding protein-1 (IGFBP-1) concentration was measured at 15-min intervals from the onset of the study until 120 min post-exercise. Blood was also sampled for the measurement of plasma glucose, insulin, non-esterified fatty acids, IGFBP-3, melatonin and vasopressin concentration. There was an exercise-induced increase in GH concentration following melatonin which was greater compared with placebo as assessed by both area under the curve (P < 0.01) and peak increase in GH levels (P < 0.01). The peak increase in IGFBP-1 levels post-exercise was also significantly greater following melatonin compared with placebo (P < 0.01) but did not quite reach levels of significance as measured by area under the curve (P = 0.07). Since exercise-induced GH secretion is thought to be mediated predominantly through a hypothalamic pathway, it seems likely that melatonin facilitates GH secretion at a hypothalamic level.

show abstract

“…Chalmers et al, under control conditions and during an octreotide infusion to suppress endogenous GH release, measured plasma metabolites including glucose, glycerol and free fatty acids during 30 min of exercise at 70% of VO 2max and 90 min of recovery [103]. No significant effect of GH Fig.…”

Section: Studies In Normal Subjectsmentioning

confidence: 97%