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R. A. Defronzo - One of the best experts on this subject based on the ideXlab platform.

  • A novel mechanism of glipizide sulfonylurea action: decreased Metabolic Clearance Rate of insulin
    Acta Diabetologica, 1995
    Co-Authors: N. Barzilai, P. -h. Groop, L. Groop, R. A. Defronzo
    Abstract:

    To examine whether sulfonylureas inhibit the Metabolic Clearance Rate (MCR) of insulin, 19 healthy young subjects participated in two experiments. In the first protocol ( n =10), a 3-h oral glucose load was performed with and without 2 mg of glipizide given 30 min before glucose ingestion. The total insulin response was 60% greater with than without glipizide (5.9±0.6 vs 3.7±0.5 μU/ml; P

  • a novel mechanism of glipizide sulfonylurea action decreased Metabolic Clearance Rate of insulin
    Acta Diabetologica, 1995
    Co-Authors: N. Barzilai, L. Groop, Perhenrik Groop, R. A. Defronzo
    Abstract:

    To examine whether sulfonylureas inhibit the Metabolic Clearance Rate (MCR) of insulin, 19 healthy young subjects participated in two experiments. In the first protocol (n=10), a 3-h oral glucose load was performed with and without 2 mg of glipizide given 30 min before glucose ingestion. The total insulin response was 60% greater with than without glipizide (5.9±0.6 vs 3.7±0.5 μU/ml;P<0.001). However, the total C-peptide responses were virtually identical (4.7±0.5 vs 4.8±0.4 nmol/l) in both studies. In the second protocol (n=9), the MCR of insulin was measured during 4-h euglycemic insulin clamps performed with and without glipizide. In the study with glipizide, the subjects ingested 5 mg of glipizide at 120 min. The steady-state plasma insulin concentration during the 4th h, i.e., 1–2 h after glipizide ingestion, was significantly higher than during the 2nd h, i.e., before glipizide ingestion (99±22 vs 78±17 μU/ml;P<0.01). In addition, glucose uptake during the 4th h was greater (8.0±1.6 vs 6.4±1.5 mg/kg·min) and the MCR of insulin was reduced (503±126 vs 621±176 ml/m2·min;P<0.01). We conclude that glipizide augments plasma insulin levels both by enhancing its secretion and by decreasing the MCR of insulin.

N. Barzilai - One of the best experts on this subject based on the ideXlab platform.

  • A novel mechanism of glipizide sulfonylurea action: decreased Metabolic Clearance Rate of insulin
    Acta Diabetologica, 1995
    Co-Authors: N. Barzilai, P. -h. Groop, L. Groop, R. A. Defronzo
    Abstract:

    To examine whether sulfonylureas inhibit the Metabolic Clearance Rate (MCR) of insulin, 19 healthy young subjects participated in two experiments. In the first protocol ( n =10), a 3-h oral glucose load was performed with and without 2 mg of glipizide given 30 min before glucose ingestion. The total insulin response was 60% greater with than without glipizide (5.9±0.6 vs 3.7±0.5 μU/ml; P

  • a novel mechanism of glipizide sulfonylurea action decreased Metabolic Clearance Rate of insulin
    Acta Diabetologica, 1995
    Co-Authors: N. Barzilai, L. Groop, Perhenrik Groop, R. A. Defronzo
    Abstract:

    To examine whether sulfonylureas inhibit the Metabolic Clearance Rate (MCR) of insulin, 19 healthy young subjects participated in two experiments. In the first protocol (n=10), a 3-h oral glucose load was performed with and without 2 mg of glipizide given 30 min before glucose ingestion. The total insulin response was 60% greater with than without glipizide (5.9±0.6 vs 3.7±0.5 μU/ml;P<0.001). However, the total C-peptide responses were virtually identical (4.7±0.5 vs 4.8±0.4 nmol/l) in both studies. In the second protocol (n=9), the MCR of insulin was measured during 4-h euglycemic insulin clamps performed with and without glipizide. In the study with glipizide, the subjects ingested 5 mg of glipizide at 120 min. The steady-state plasma insulin concentration during the 4th h, i.e., 1–2 h after glipizide ingestion, was significantly higher than during the 2nd h, i.e., before glipizide ingestion (99±22 vs 78±17 μU/ml;P<0.01). In addition, glucose uptake during the 4th h was greater (8.0±1.6 vs 6.4±1.5 mg/kg·min) and the MCR of insulin was reduced (503±126 vs 621±176 ml/m2·min;P<0.01). We conclude that glipizide augments plasma insulin levels both by enhancing its secretion and by decreasing the MCR of insulin.

L. Groop - One of the best experts on this subject based on the ideXlab platform.

  • A novel mechanism of glipizide sulfonylurea action: decreased Metabolic Clearance Rate of insulin
    Acta Diabetologica, 1995
    Co-Authors: N. Barzilai, P. -h. Groop, L. Groop, R. A. Defronzo
    Abstract:

    To examine whether sulfonylureas inhibit the Metabolic Clearance Rate (MCR) of insulin, 19 healthy young subjects participated in two experiments. In the first protocol ( n =10), a 3-h oral glucose load was performed with and without 2 mg of glipizide given 30 min before glucose ingestion. The total insulin response was 60% greater with than without glipizide (5.9±0.6 vs 3.7±0.5 μU/ml; P

  • a novel mechanism of glipizide sulfonylurea action decreased Metabolic Clearance Rate of insulin
    Acta Diabetologica, 1995
    Co-Authors: N. Barzilai, L. Groop, Perhenrik Groop, R. A. Defronzo
    Abstract:

    To examine whether sulfonylureas inhibit the Metabolic Clearance Rate (MCR) of insulin, 19 healthy young subjects participated in two experiments. In the first protocol (n=10), a 3-h oral glucose load was performed with and without 2 mg of glipizide given 30 min before glucose ingestion. The total insulin response was 60% greater with than without glipizide (5.9±0.6 vs 3.7±0.5 μU/ml;P<0.001). However, the total C-peptide responses were virtually identical (4.7±0.5 vs 4.8±0.4 nmol/l) in both studies. In the second protocol (n=9), the MCR of insulin was measured during 4-h euglycemic insulin clamps performed with and without glipizide. In the study with glipizide, the subjects ingested 5 mg of glipizide at 120 min. The steady-state plasma insulin concentration during the 4th h, i.e., 1–2 h after glipizide ingestion, was significantly higher than during the 2nd h, i.e., before glipizide ingestion (99±22 vs 78±17 μU/ml;P<0.01). In addition, glucose uptake during the 4th h was greater (8.0±1.6 vs 6.4±1.5 mg/kg·min) and the MCR of insulin was reduced (503±126 vs 621±176 ml/m2·min;P<0.01). We conclude that glipizide augments plasma insulin levels both by enhancing its secretion and by decreasing the MCR of insulin.

S Brown - One of the best experts on this subject based on the ideXlab platform.

  • Metabolic Clearance Rate of testosterone in male epileptic patients on anti convulsant therapy
    Journal of Endocrinology, 1991
    Co-Authors: M J Wheeler, B K Toone, A Dannatt, P B C Fenwick, S Brown
    Abstract:

    There are several reports which state that male epileptics on anti-convulsant therapy have reduced sexual activity. We and others have shown that, although total testosterone is raised, the free testosterone concentration is reduced in this patient population. This could be a result of an increased Metabolic Clearance Rate (MCR) of testosterone, inadequate secretion of LH to stimulate testosterone synthesis or inappropriately low testosterone production by the Leydig cells. We have examined these possibilities by measuring the MCR of testosterone in 15 male epileptics on anti-convulsant therapy. In this group of patients, the mean LH (9.3 +/- 5.9 IU/l) and sex-hormone binding globulin (SHBG) (54.5 +/- 22.9 nmol/l) concentrations were significantly greater than those of five normal control subjects (4.7 +/- 1.11 IU/l and 26.0 +/- 7.0 nmol/l respectively). Mean total testosterone concentrations of the two groups were not significantly different but the mean percentage of free testosterone and free testosterone concentration were significantly lower in the patient population (2.06 +/- 0.43 vs 2.98 +/- 0.27 and 0.56 +/- 1.1 vs 0.79 +/- 0.07 pmol/l). The MCR of testosterone was significantly lower in the patients (773 +/- 322 vs 1354 +/- 443 l/day) and showed a positive correlation with the percentage of free testosterone. Therefore, our results suggest that the lowered free testosterone in male epileptics on anti-convulsant therapy is not due to an increased MCR of testosterone. The increased LH concentration suggests primary hypogonadism. This, in turn, could be responsible for low free testosterone levels in the presence of normal testosterone.

Helen C Atkinson - One of the best experts on this subject based on the ideXlab platform.

  • production Rate Metabolic Clearance Rate and uterine extraction of corticosterone during rat pregnancy
    Journal of Endocrinology, 1994
    Co-Authors: Brendan J Waddell, Helen C Atkinson
    Abstract:

    This study examined changes in the blood concentration of corticosterone with the onset and progression of pregnancy in the rat. To identify the source of variation in blood corticosterone, the Metabolic Clearance Rate (MCR) and production Rate of corticosterone were also determined. Measurements were made in conscious rats (n = 4-7 per group) in the morning of dioestrus and days 5, 10, 16 and 22 of pregnancy (term = day 23). Corticosterone levels were 713 +/- 38 nmol/l (mean +/- S.E.M.) in non-pregnant rats, remained unchanged to day 10 of pregnancy, then increased to 1036 +/- 52 nmol/l by day 16 and remained high at day 22. The production Rate of corticosterone appeared to increase during pregnancy from 25.6 +/- 1.7 mumol/day on day 10 to reach 36.3 +/- 3.3 mol/day on day 22, but this did not reach statistical significance (one-way ANOVA). The MCR of corticosterone was similar among all groups (overall mean 34.6 +/- 2.5 l/day), although a slight but non-significant fall was apparent at day 16. When account was taken of changes in maternal weight, the MCR decreased progressively from 139 +/- 10 1/day per kg before pregnancy to reach a minimum of 88 +/- 7 1/day per kg on day 16. Transuterine extraction of corticosterone on day 22 of pregnancy was 19.2 +/- 3.1% and so, based on this and estimates of uterine blood flow, the uterus must account for around 15% of corticosterone Clearance at this time. Because this uterine contribution is effectively additional Clearance, it is likely that without it the MCR of corticosterone would have fallen during pregnancy.(ABSTRACT TRUNCATED AT 250 WORDS)