المؤلفون: Donna B. Tate, Sachiko Morrey, Pietro Galassetti, David H. Wasserman, Ray A. Neill, Stephen N. Davis

المصدر: American Journal of Physiology-Endocrinology and Metabolism. 287:E16-E24

مصطلحات موضوعية: Adult, Blood Glucose, Male, medicine.medical_specialty, Epinephrine, Hydrocortisone, endocrine system diseases, Physiology, Endocrinology, Diabetes and Metabolism, Physical exercise, Hypoglycemia, Pancreatic Polypeptide, Norepinephrine, Oxygen Consumption, Sex Factors, Physiology (medical), Internal medicine, Diabetes mellitus, medicine, Homeostasis, Humans, Insulin, Exercise, Pancreatic hormone, Type 1 diabetes, business.industry, nutritional and metabolic diseases, Glucagon, medicine.disease, Adaptation, Physiological, Neurosecretory Systems, Sexual dimorphism, Diabetes Mellitus, Type 1, Antecedent (behavioral psychology), Endocrinology, Growth Hormone, Glucose Clamp Technique, Catecholamine, Female, business, medicine.drug

الوصف: A marked sexual dimorphism exists in healthy individuals in the pattern of blunted neuroendocrine and metabolic responses following antecedent stress. It is unknown whether significant sex-related counterregulatory differences occur during prolonged moderate exercise after antecedent hypoglycemia in type 1 diabetes mellitus (T1DM). Fourteen patients with T1DM (7 women and 7 men) were studied during 90 min of euglycemic exercise at 50% maximal O2consumption after two 2-h episodes of previous-day euglycemia (5.0 mmol/l) or hypoglycemia of 2.9 mmol/l. Men and women were matched for age, glycemic control, duration of diabetes, and exercise fitness and had no history or evidence of autonomic neuropathy. Exercise was performed during constant “basal” intravenous infusion of regular insulin (1 U/h) and a 20% dextrose infusion, as needed to maintain euglycemia. Plasma glucose and insulin levels were equivalent in men and women during all exercise and glucose clamp studies. Antecedent hypoglycemia produced a relatively greater ( P < 0.05) reduction of glucagon, epinephrine, norepinephrine, growth hormone, and metabolic (glucose kinetics) responses in men compared with women during next-day exercise. After antecedent hypoglycemia, endogenous glucose production (EGP) was significantly reduced in men only, paralleling a reduction in the glucagon-to-insulin ratio and catecholamine responses. In conclusion, a marked sexual dimorphism exists in a wide spectrum of blunted counterregulatory responses to exercise in T1DM after prior hypoglycemia. Key neuroendocrine (glucagon, catecholamines) and metabolic (EGP) homeostatic responses were better preserved during exercise in T1DM women after antecedent hypoglycemia. Preserved counterregulatory responses during exercise in T1DM women may confer greater protection against hypoglycemia than in men with T1DM.

الوصول الحر: https://explore.openaire.eu/search/publication?articleId=doi_dedup___::b5bf2dc24022f333470bdc45d3fd3981Test
https://doi.org/10.1152/ajpendo.00480.2002Test

المؤلفون: Jonathan Q. Purnell, D. Lynn Loriaux, John D. Brunzell, Mary H. Samuels, Steven E. Kahn, David D. Brandon

المصدر: American Journal of Physiology-Endocrinology and Metabolism. 296:E351-E357

مصطلحات موضوعية: Adult, Male, medicine.medical_specialty, Hydrocortisone, Intra-Abdominal Fat, Metabolic Clearance Rate, Physiology, Endocrinology, Diabetes and Metabolism, Endogeny, Biology, Gene Expression Regulation, Enzymologic, Young Adult, Insulin resistance, Downregulation and upregulation, Weight loss, Physiology (medical), Internal medicine, 11-beta-Hydroxysteroid Dehydrogenase Type 1, Weight Loss, medicine, Humans, Obesity, Aged, Articles, Middle Aged, Deuterium, medicine.disease, Up-Regulation, Endocrinology, Injections, Intravenous, Insulin Resistance, medicine.symptom, Clearance rate, medicine.drug

الوصف: Controversy exists as to whether endogenous cortisol production is associated with visceral obesity and insulin resistance in humans. We therefore quantified cortisol production and clearance rates, abdominal fat depots, insulin sensitivity, and adipocyte gene expression in a cohort of 24 men. To test whether the relationships found are a consequence rather than a cause of obesity, eight men from this larger group were studied before and after weight loss. Daily cortisol production rates (CPR), free cortisol levels (FC), and metabolic clearance rates (MCR) were measured by stable isotope methodology and 24-h sampling; intra-abdominal fat (IAF) and subcutaneous fat (SQF) by computed tomography; insulin sensitivity (SI) by frequently sampled intravenous glucose tolerance test; and adipocyte 11β-hydroxysteroid dehydrogenase-1 (11β-HSD-1) gene expression by quantitative RT-PCR from subcutaneous biopsies. Increased CPR and FC correlated with increased IAF, but not SQF, and with decreased SI. Increased 11β-HSD-1 gene expression correlated with both IAF and SQF and with decreased SI. With weight loss, CPR, FC, and MCR did not change compared with baseline; however, with greater loss in body fat than lean mass during weight loss, both CPR and FC increased proportionally to final fat mass and IAF and 11β-HSD-1 decreased compared with baseline. These data support a model in which increased hypothalamic-pituitary-adrenal activity in men promotes selective visceral fat accumulation and insulin resistance and may promote weight regain after diet-induced weight loss, whereas 11β-HSD-1 gene expression in SQF is a consequence rather than cause of adiposity.

الوصول الحر: https://explore.openaire.eu/search/publication?articleId=doi_dedup___::d97946583a4d345108c6206e1e234de5Test
https://doi.org/10.1152/ajpendo.90769.2008Test

المؤلفون: Anne Dutour, F. Dadoun, Marie-Christine Alessi, Sandrine Boullu-Ciocca, Patrice Darmon, Michel Grino

المصدر: American Journal of Physiology-Endocrinology and Metabolism. 291:E995-E1002

مصطلحات موضوعية: Adult, Blood Glucose, medicine.medical_specialty, Hydrocortisone, Physiology, Endocrinology, Diabetes and Metabolism, Abdominal Fat, Anti-Inflammatory Agents, Fatty Acids, Nonesterified, Sodium Chloride, Insulin resistance, Physiology (medical), Internal medicine, Plasminogen Activator Inhibitor 1, medicine, Homeostasis, Humans, Insulin, In patient, Obesity, Abdominal obesity, business.industry, Middle Aged, medicine.disease, Endocrinology, Normal weight, Regression Analysis, Female, Adiponectin, Insulin Resistance, medicine.symptom, business, Stress, Psychological, Visceral Obesity, medicine.drug

الوصف: Glucocorticoids hypersensitivity may be involved in the development of abdominal obesity and insulin resistance. Eight normal weight and eight obese women received on two occasions a 3-h intravenous infusion of saline or hydrocortisone (HC) (1.5 μg·kg−1·min−1). Plasma cortisol, insulin, and glucose levels were measured every 30 min from time−30(min) (time−30) to time240. Free fatty acids, adiponectin, and plasminogen activator inhibitor-1 (PAI-1) levels were measured at time−30, time180, and time240. At time240, subjects underwent an insulin tolerance test to obtain an index of insulin sensitivity (KITT). Mean30–240cortisol level was similar in control and obese women after saline (74 ± 16 vs. 75 ± 20 μg/l) and HC (235 ± 17 vs. 245 ± 47 μg/l). The effect of HC on mean180–240insulin, mean180–240insulin resistance obtained by homeostasis model assessment (HOMA-IR), and KITTwas significant in obese (11.4 ± 2.0 vs. 8.2 ± 1.3 mU/l, P < 0.05; 2.37 ± 0.5 vs. 1.64 ± 0.3, P < 0.05; 2.81 ± 0.9 vs. 3.32 ± 1.02%/min, P < 0.05) but not in control women (3.9 ± 0.6 vs. 2.8 ± 0.5 mU/l; 0.78 ± 0.1 vs. 0.49 ± 0.1; 4.36 ± 1.1 vs. 4.37 ± 1.2%/min). In the whole population, the quantity of visceral fat, estimated by computerized tomography scan, was correlated with the increment of plasma insulin and HOMA-IR during HC infusion [Δmean30–240insulin ( r = 0.61, P < 0.05), Δmean30–240HOMA-IR ( r = 0.66, P < 0.01)]. The increase of PAI-1 between time180and time240after HC was higher in obese women (+25%) than in controls (+12%) ( P < 0.05), whereas no differential effect between groups was observed for free fatty acids or adiponectin. A moderate hypercortisolism, equivalent to that induced by a mild stress, has more pronounced consequences on insulin sensitivity in abdominally obese women than in controls. These deleterious effects are correlated with the amount of visceral fat.

الوصول الحر: https://explore.openaire.eu/search/publication?articleId=doi_dedup___::f31632748240f68bae2d312813456c46Test
https://doi.org/10.1152/ajpendo.00654.2005Test

المؤلفون: M. A. Richardson, Paul J. Flakoll, Darleen A. Sandoval, Donna B. Tate, Stephen N. Davis, Deanna L. Aftab Guy

المصدر: American Journal of Physiology-Endocrinology and Metabolism. 288:E178-E186

مصطلحات موضوعية: Adult, Blood Glucose, Male, medicine.medical_specialty, Epinephrine, Hydrocortisone, endocrine system diseases, Physiology, Biopsy, Endocrinology, Diabetes and Metabolism, medicine.medical_treatment, Glucose uptake, Blood Pressure, Autonomic Nervous System, Pancreatic Polypeptide, Glucagon, Norepinephrine, NEFA, Heart Rate, Physiology (medical), Internal medicine, Diabetes mellitus, medicine, Humans, Insulin, Sympathomimetics, Muscle, Skeletal, Human Growth Hormone, business.industry, Calorimetry, Indirect, Glucose clamp technique, medicine.disease, Diabetes Mellitus, Type 1, Endocrinology, Glucose Clamp Technique, Female, business, medicine.drug

الوصف: Acute increases of the key counterregulatory hormone epinephrine can be modified by a number of physiological and pathological conditions in type 1 diabetic patients (T1DM). However, it is undecided whether the physiological effects of epinephrine are also reduced in T1DM. Therefore, the aim of this study was to determine whether target organ (liver, muscle, adipose tissue, pancreas, cardiovascular) responses to epinephrine differ between healthy subjects and T1DM patients. Thirty-four age- and weight-matched T1DM ( n = 17) and healthy subjects ( n = 17) underwent two randomized, single-blind, 2-h hyperinsulinemic euglycemic clamp studies with (Epi) and without epinephrine infusion. Muscle biopsy was performed at the end of each study. Epinephrine levels during Epi were similar in all groups (4,039 ± 384 pmol/l). Glucose (5.3 ± 0.06 mmol/l) and insulin levels (462 ± 18 pmol/l) were also similar in all groups during the glucose clamps. Glucagon responses to Epi were absent in T1DM and significantly reduced compared with healthy subjects. Endogenous glucose production during the final 30 min was significantly greater during Epi in healthy subjects compared with T1DM (8.4 ± 1.3 vs. 4.4 ± 0.6 μmol·kg−1·min−1, P = 0.041). Glucose uptake showed almost a twofold greater decrease with Epi in healthy subjects vs. T1DM (Δ31 ± 2 vs. Δ17 ± 2 nmol·kg−1·min−1, respectively, P = 0.026). Glycerol, β-hydroxybutyrate, and nonesterified fatty acid (NEFA) all increased significantly more in T1DM compared with healthy subjects. Increases in systolic blood pressure were greater in healthy subjects, but reductions of diastolic blood pressure were greater in T1DM patients with Epi. Reduction of glycogen synthase was significantly greater during epinephrine infusion in T1DM vs. healthy subjects. In summary, despite equivalent epinephrine, insulin, and glucose levels, changes in glucose flux, glucagon, and cardiovascular responses were greater in healthy subjects compared with T1DM. However, T1DM patients had greater lipolytic responses (glycerol and NEFA) during Epi. Thus we conclude that there is a spectrum of significant in vivo physiological differences of epinephrine action at the liver, muscle, adipose tissue, pancreas, and cardiovascular system between T1DM and healthy subjects.

الوصول الحر: https://explore.openaire.eu/search/publication?articleId=doi_dedup___::136e931bd18a0eab8ad6f0bbbce6d7caTest
https://doi.org/10.1152/ajpendo.00310.2004Test

المؤلفون: Joseph G. Cannon, Richard W. Ball, Jane M. Daun

المصدر: American Journal of Physiology-Regulatory, Integrative and Comparative Physiology. 278:R855-R862

مصطلحات موضوعية: Adult, Lipopolysaccharides, Male, medicine.medical_specialty, Hydrocortisone, Physiology, Sialoglycoproteins, medicine.medical_treatment, Anti-Inflammatory Agents, Down-Regulation, Inflammation, Luteal Phase, Biology, Sex Factors, Mediator, Glucocorticoid Sensitivity, Physiology (medical), Internal medicine, Leukocytes, medicine, Humans, Receptors, Interleukin-1 Type II, Receptor, Cells, Cultured, Dose-Response Relationship, Drug, Age Factors, Receptors, Interleukin-1, Interleukin, Middle Aged, Interleukin 1 Receptor Antagonist Protein, Cytokine, Endocrinology, Follicular Phase, Solubility, Female, medicine.symptom, Glucocorticoid, Interleukin-1, medicine.drug

الوصف: Interleukin-1 (IL-1) is a primary mediator of inflammation that is regulated, in part, by the hypothalamic-pituitary-adrenal axis. The purpose of this study was to determine if gender- or age-related differences exist in the sensitivity of IL-1-producing cells to hydrocortisone. Peripheral blood mononuclear cells (PBMC) isolated from men and women (21–77 yr old) were incubated with hydrocortisone (0, 50, 100, 500, or 1,000 ng/ml) with or without lipopolysaccharide (LPS). Secretion of IL-1β and IL-1 receptor antagonist was inhibited in a dose-dependent manner ( P = 0.001) without age- or gender-related differences. Hydrocortisone decreased soluble IL-1 receptor type II (sIL-1RII) secretion by unstimulated cells ( P = 0.0001), but it increased secretion by LPS-stimulated cells ( P = 0.0001) in all groups. Unstimulated cell supernatants from men contained greater concentrations of sIL-1RII than the supernatants from women ( P= 0.011). Compared with men, PBMCs from women were less responsive to hydrocortisone inhibition of sIL-1RII secretion, regardless of age ( P = 0.001), and compared with the follicular phase, sIL-1RII secretion was lower in the luteal phase of the menstrual cycle ( P < 0.05). These data indicate that basal secretion and glucocorticoid modulation of sIL-1RII secretion by cultured PBMCs are gender dependent. Moreover, glucocorticoid influences on sIL-1RII secretion depend on the presence or absence of gram-negative bacterial toxins.

الوصول الحر: https://explore.openaire.eu/search/publication?articleId=doi_dedup___::6500192a5eacc6b4b9cc8f1b778950d1Test
https://doi.org/10.1152/ajpregu.2000.278.4.r855Test

المؤلفون: Philip E. Cryer, J. C. Marker, Katherine R. Tuttle, William E. Clutter, N. S. Schwartz, John O. Holloszy, Suresh D. Shah, G. P. Dalsky

المصدر: American Journal of Physiology-Endocrinology and Metabolism. 254:E713-E719

مصطلحات موضوعية: Adult, Blood Glucose, Glycerol, Male, medicine.medical_specialty, Epinephrine, Hydrocortisone, Physiology, Endocrinology, Diabetes and Metabolism, medicine.medical_treatment, Physical Exertion, Hydroxybutyrates, Blood Pressure, Physical exercise, Propranolol, Fatty Acids, Nonesterified, Hypoglycemia, Glucagon, Norepinephrine, Oxygen Consumption, Heart Rate, Physiology (medical), Diabetes mellitus, Internal medicine, medicine, Humans, Insulin, Alanine, 3-Hydroxybutyric Acid, business.industry, medicine.disease, Diabetes Mellitus, Type 1, Endocrinology, Growth Hormone, Lactates, Regular insulin, Catecholamine, Female, business, medicine.drug

الوصف: The sympathochromaffin system, probably sympathetic neural norepinephrine, plays a primary role in the prevention of hypoglycemia during exercise in humans. Our previous data indicated that changes in pancreatic islet hormones are not normally critical but decrements in insulin, increments in glucagon, or both become critical when catecholamine actions are blocked pharmacologically. To distinguish between the role of insulin and that of glucagon in this secondary line of defense against hypoglycemia during exercise in humans, glucoregulation during moderate exercise (approximately 55% of maximum O2 consumption over 60 min) was studied in people who could not decrease insulin but could increase glucagon, i.e., patients with insulin-dependent diabetes mellitus (IDDM). While receiving constant intravenous infusions of regular insulin, in individualized doses shown to result in stable plasma glucose concentrations of approximately 95 mg/dl before exercise, patients with IDDM were studied under two conditions: 1) a control study (n = 13) and 2) an adrenergic blockade study (propranolol infusion, n = 8). In the control study, mean plasma glucose concentrations did not change (from 95 +/- 2 to 100 +/- 11 mg/dl) during exercise despite constant plasma free insulin levels. In the adrenergic blockade study plasma glucose declined (from 96 +/- 2 to 74 +/- 7 mg/dl, P less than 0.01) but stabilized; hypoglycemia did not occur. Exercise-associated increments in plasma glucagon were comparable in the two studies. These data confirm that decrements in insulin are not critical to the prevention of hypoglycemia during moderate exercise in humans and indicate that compensation for deficient catecholamine action does not require decrements in insulin.(ABSTRACT TRUNCATED AT 250 WORDS)

الوصول الحر: https://explore.openaire.eu/search/publication?articleId=doi_dedup___::51a63b2a4bac894cbecd5938ab469a73Test
https://doi.org/10.1152/ajpendo.1988.254.6.e713Test