PubMed Health⌕ Search

Biomedical subjects

T Mantzouridis

Publications and source records attributed to T Mantzouridis.

5 recordsLinked to original sources
PubMed2007

Positive correlation of galanin with glucose in healthy volunteers during an oral glucose tolerance test.

Galanin has been found in increased amounts in subjects with type 2 diabetes. The purpose of the present study was to determine the levels of galanin in healthy volunteers during an oral glucose tolerance test (OGTT). We enrolled 11 healthy volunteers, 4 males aged 48+/-3.56 years with BMI 27+/-0.5 kg/m (2) and 7 females aged 41.3+/-3.05 years with BMI 27.6+/-0.9 kg/m (2). All were in good health without cardiac, hepatic, renal or other chronic disease. None were taking any medication affecting glucose tolerance (beta-blockers, thiazide diuretics, and corticoids) and none had a first degree relative with type 2 diabetes. Glucose tolerance was determined by using the International Expert Committee criteria. Blood samples were collected at 0, 30, 60, 90, 120 and 180 minutes for the measurement of plasma glucose, insulin, C-peptide and human galanin (hGal). During the OGTT, hGal exhibited a significant increase from time 0 to 90 minutes (p < 0.001) and returned to the basal values at 180 minutes, while a positive correlation of blood glucose with hGal was observed during the time scale of OGTT. A significant increase was detected both in insulin and C-peptide from the early beginning of the test at 30 minutes, which remained steady until 90 minutes, and returned gradually to the basal values at 180 minutes. No relationship was found either between hGal and serum insulin, or between hGal and serum C-peptide among the healthy subjects, during the OGTT.

Adult↗
PubMed2004

Rapid decrease of leptin in middle-aged sedentary individuals after 20 minutes of vigorous exercise with early recovery after the termination of the test.

This study investigated the leptin response to vigorous exercise. We examined 12 sedentary subjects (7 males and 5 females) aged 45-59 yr (53 +/- 6.3) with body mass index of 26.1 +/- 8 Kg/m2. The selection of the population was based on the absence of endocrine or any other pathological anomaly. Basal concentrations of leptin, cortisol, insulin and glucose were measured at 08:00 h after an overnight fast. After that the individuals were placed on a computer-controlled ergometer performing a 20-min run at 70% VO2 max under controlled environmental conditions. Blood samples were obtained immediately after the completion of the test. For the following hour, all subjects were placed in the supine position and blood samples were taken at the end of the time period. Statistical evaluation was performed using analysis of variance (ANOVA) for independent variables. Plasma leptin levels exhibited a statistically significant decrease at the end of the 20 min running period (1.5 +/- 0.1 ng/ml vs 3.2 +/- 0.4 ng/ml, p<0.005). Interestingly, after 1 h in the supine position, leptin levels reached the basal values (3.17 +/- 0.1 ng/ml). The concentration of insulin, glucose and cortisol were unaltered during the exercise test (9.8 +/- 1.3 vs 8.85 +/- 1.27 microIU/ml, 95.58 +/- 6.71 mg/dl vs 98.4 +/- 0.78 mg/dl and 10.35 +/- 0.74 microg/dl vs 9.5 +/- 0.7 microg/dl respectively). In conclusion, our data demonstrate a relationship between stressful physical activity and plasma leptin levels in middle-aged subjects.

Blood Glucose↗
PubMed2000

Human galanin secretion is increased upon normal exercise test in middle-age individuals.

Galanin, a neuropeptide, is found in the central nervous system and in a number of nonbrain areas including adrenal sympathetic medullar tissue and pancreas. Several studies involve galanin in the regulation of GH, which responds to stressful stimuli. This study refers to the investigation of the effect of a 20-min exercise on plasma human galanin (hGAL) and GH in middle-aged healthy volunteer adults. Thirteen individuals, 5 males and 8 females aged 40-50 years (44.7 +/- 2.95) were selected on the basis of normal body mass index (22.5 +/- 2.3 kg/m2) and the absence of endocrine or any other abnormality. Basal concentrations of GH and hGAL were measured between 0800 and 0900h after an overnight fast. Post exercise levels were recorded after termination of the stressful test and 15 min thereafter. GH and hGAL were determined by an immunoradiometric and radioimmunoassay, respectively. The exercise-potentiated GH response in all subjects with post-exercise levels significantly higher (11.09 +/- 1.8 ng/ml vs 1.27 +/- 0.7 ng/ml, p<0.0001, F=32.44) with the peak in the hormone level detected 15 min after the end of exercise (12.09 +/- 1.96 ng/ml). Plasma hGAL levels were also substantially affected by the acute exercise test, in that post exercise peripheral blood concentration was significantly higher from the basal values (21.51 +/- 9.94 vs 13.46 +/- 7.2 pg/ml, p<0.02, F=5.50). Again the hGAL values peaked 15 min after the end of exercise (24.0 +/- 10.5 pg/ml, P<0.015, F = 4.68). However, the time-correlation of the increments of GH and hGAL did not reach a statistically significant level (20 min: r=0.41, p=0.161., 35 min: r=-0.095, P=0.758). These results clearly show an independence of the two hormones. The responsivity of hGAL of middle-aged individuals to the exercise stimulus might be due to the higher releasable pool of the hormone.

Adult↗
PubMed1989

Alpha 2-adrenergic, kappa-opiate, and P1-purinergic autoreceptors have mutually antagonistic effects: a new regulatory mechanism?

Rat cortical synaptosomes prepared on four-step discontinuous Percoll density gradients were loaded with the fluorescent Ca2+-indicator fura-2 to allow measurement of the intrasynaptosomal free calcium concentration ([Ca2+]i). When P1-purinergic, alpha 2-adrenergic, or kappa-opiate agonists were incubated with these synaptosomes for 1 min, there was a highly significant, dose-dependent reduction in [Ca2+]i. The effects of these agonists were blocked by inclusion of appropriate specific antagonists. When alpha 2-adrenergic and P1-purinergic agonists were coincubated, a mutual antagonism of their effects was observed, and, in fact, an increase rather than a decrease in [Ca2+]i was apparent. This mutual antagonism was reversed by addition of either a P1-purinergic or a alpha 2-adrenergic antagonist. Parallel studies in which kappa-opiate and P1-purinergic agonists were coincubated also demonstrated a mutual antagonism between the individual effects that was reversed by prior inclusion of either a kappa-opiate or P1-purinergic antagonist. As these mutually antagonistic effects have been observed between alpha 2-adrenergic, kappa-opiate, and P1-purinergic receptor-mediated events, we suggest that this may be a general phenomenon and may be a regulatory mechanism at nerve endings.

3,4-Dichloro-N-methyl-N-(2-(1-pyrrolidinyl)-cycloh↗