Estimation of second-phase insulin secretion in the Zucker fatty rat.

The purpose of the present study was to test the efficacy of the empiric index SPIR (Second-phase Insulin Release) in the quantification of second-phase insulin secretion in the Zucker Fatty Rat. SPIR index is defined as the area under the curve of insulin between 8 and 90 min after an Intravenous Glucose Tolerance Test (IVGTT). The validation of such index was performed against the second-phase β-cell responsiveness index (Φ) provided by C-peptide minimal model.

C-Peptide-based assessment of insulin secretion in the Zucker Fatty rat: a modelistic study.

A C-peptide-based assessment of β-cell function was performed here in the Zucker fatty rat, a suitable animal model of human metabolic syndrome. To this aim, a 90-min intravenous glucose tolerance test (IVGTT) was performed in seven Zucker fatty rats (ZFR), 7-to-9 week-old, and seven age-matched Zucker lean rats (ZLR). The minimal model of C-peptide (CPMM), originally introduced for humans, was adapted to Zucker rats and then applied to interpret IVGTT data.

Systemic administration of mesenchymal stem cells increases neuron survival after global cerebral ischemia in vivo (2VO).

Although many studies have shown that administration of stem cells after focal cerebral ischemia improves brain damage, very little data are available concerning the damage induced by global cerebral ischemia. The latter causes neuronal death in selectively vulnerable areas, including the hippocampal CA1 region. We tested the hypothesis that intravenous infusion of bone marrowderived stromal cells (mesenchimal stem cells, MSC) reduce brain damage after transient global ischemia.

Age-related analysis of insulin resistance, body weight and arterial pressure in the Zucker fatty rat.

The evolution with ageing of insulin resistance, body weight (BW) and mean arterial pressure (MAP) was studied in a group of Zucker fatty rats (ZFRs, n = 22), between 7 and 16 weeks of age, compared with an age-matched control group of Zucker lean rats (ZLRs, n = 22). The minimal model of glucose kinetics was applied to estimate glucose effectiveness, S(G), and insulin sensitivity, S(I), from insulinaemia and glycaemia measured during a 70 min intravenous glucose tolerance test. No correlation was found between S(G) and age in both ZFR and ZLR groups.

Postural control after a strenuous treadmill exercise.

The effect of a strenuous treadmill exercise on body stability and the mechanisms associated with it have been studied with two different experimental protocols. The former investigation was based on stabilometric and metabolic measurements performed in basal condition and after a strenuous treadmill exercise whilst the latter dealt with the study of the early postural response to a 3s-bilateral soleus muscle vibration after the strenuous exercise. Our exercise protocol was able to induce an important generalized metabolic fatigue, as assessed by the obtained peak values in the measured metabolic parameters, and resulting in a short-lasting body destabilization.

Enhanced sympathetic reactivity associates with insulin resistance in the young Zucker rat.

Somatosympathetic reflexes were studied in young hyperinsulinemic, insulin-resistant (Zucker fatty) rats (ZFR) and a related control (Zucker lean) strain (ZLR). Glucose metabolism was characterized by minimal model analysis of intravenous glucose tolerance test data. Seven-week-old ZFR (n=18) and ZLR (n=17) were studied under pentobarbital anesthesia.

Age-related analysis of glucose metabolism in spontaneously hypertensive and normotensive rats.

This study was designed to investigate the effect of both hypertension and ageing on the efficiency of glucose metabolism. A 12-sample, 120 min intravenous glucose tolerance test (IVGTT) was applied to 36 rats: two groups of nine young (12 weeks) spontaneously hypertensive and Wistar Kyoto rats (Y-SHR and Y-WKY group, respectively) and two groups of nine old (40 weeks) SHR and WKY rats (O-SHR and O-WKY group, respectively). Insulinaemia and glycaemia data were interpreted in terms of estimates of glucose effectiveness, S(G), and insulin sensitivity, S(I), provided by the minimal model of glucose kinetics.