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Biomedical subjects

M Capelli

Publications and source records attributed to M Capelli.

At least 109 records · Page 6Linked to original sources

Gastric inhibitory polypeptide release after oral glucose: relationship to glucose intolerance, diabetes mellitus, and obesity.

Hypersecretion of immunoreactive gastric inhibitory polypeptide (IRGIP) has been reported previously in patients with diabetes mellitus (DM) and obesity. To ascertain the relative contribution of glucose intolerance and obesity to the abnormalities of IRGIP secretion, 114 subjects were studied during a standard oral glucose (75 g) tolerance test; responses of glucose, insulin, C-peptide, IRGIP, and glucagon were evaluated. The subjects were divided into six subgroups according to body weight and the degree of glucose intolerance. In normal weight subjects, the IRGIP response to oral glucose was significantly higher in the patients with impaired glucose tolerance (IGT) and DM than in the healthy control subjects (P less than 0.05). In the obese subjects, no significant differences in mean IRGIP responses could be detected among control, IGT, and DM subjects. In spite of similar IRGIP responses, the obese IGT patients did release more insulin than the obese control subjects, suggesting that incretin factors other than GIP may be operative in this condition. When obese and nonobese patients were compared, the obese subjects with normal glucose tolerance released a greater amount of IRGIP and insulin than the normal weight controls, whereas no significant difference between obese and nonobese could be found within the IGT and DM groups. We conclude that in the absence of obesity, glucose intolerance may induce IRGIP hypersecretion. On the other hand, obesity is associated with IRGIP hypersecretion, and glucose intolerance has no further effect, indicating a different pathogenetic mechanism for the IRGIP abnormalities. In both the obese and nonobese diabetic groups, IRGIP hypersecretion was associated with a failure of plasma glucagon levels to fall after oral glucose; this effect might be related to the glucagonotropic action of this peptide.

Adult↗

The molar ratio of C-peptide to insulin after two consecutive stimulations with glucagon in obesity.

The same dose (1 mg) of intravenous glucagon, administered in two consecutive pulses, demonstrates that insulin and C-peptide secretory responses in obese patients exceed those of normal weight subjects. The analysis of the molar ratio of serum immunoreactive C-peptide (IRCP) to serum immunoreactive insulin (IRI) which revealed significant differences between obese and control groups suggests that higher plasma insulin levels in obesity may result not only from a greater response to glucagon loads and from an impaired sensitivity to endogenous insulin by target tissues, but also from a decreased hepatic removal and destruction of the hormone. Perhaps an anomaly in the hepatic handling of insulin exists in obese subjects and thus a greater amount of the hormone reaches the periphery contributing to hyperinsulinemia, as observed in hyperglycemic and hyperinsulinemic obese (ob/ ob) mice.

Adult↗

Possible mixed agonist--antagonist activity of D-sulpiride at dopamine receptor level in man.

The effects of different doses of D-sulpiride (1, 6, 12 and 25 mg, i.v.) on arterial blood pressure (ABP), heart rate (HR) and prolactin (PRL), growth hormone (GH), insulin and gastrin secretions have been studied in 8 normal men. D-Sulpiride increased systolic ABP with a maximum effect rather 12 mg i.v., while it had only slight effects on diastolic ABP and HR. PRL secretion was increased by D-sulpiride in a dose-dependent way, while insulin secretion was lowered and GH secretion slightly enhanced only in a restricted range of doses (6 mg and 12 mg i.v., respectively). Gastrin secretion seemed to be unaffected by D-sulpiride at any of the tested doses. These results are discussed in view of a possible mixed agonist--antagonist activity of D-sulpiride at dopamine receptor level in contrast with the relatively pure antagonistic action of the levo isomer.

Adult↗

Effects of the interaction between methysergide and clonidine on growth hormone and prolactin secretion in normal man.

The effects of methysergide (1 mg, p.o.), clonidine (50 micrograms, i.m.) and methysergide plus clonidine on growth hormone (GH) and prolactin (PRL) secretion in 8 normal male volunteers have been studied. Both methysergide and clonidine were found to enhance GH and to lower PRL plasma levels. The effects of methysergide are explained on the basis of a preferential action of methysergide metabolites on dopamine receptors, whereas the effects of clonidine are attributed to a stimulatory action on adrenaline receptors. The combined treatment methysergide plus clonidine resulted in a potentiation of the effects caused by the drugs when administered alone.

Adult↗

Effect of prolonged administration of ranitidine on pituitary and thyroid hormones, and their response to specific hypothalamic-releasing factors.

We have studied, in a double blind controlled trial, 30 male patients with duodenal ulcer to evaluate the effect of prolonged oral administration of ranitidine (150 mg bd for 4 weeks), a new H2-receptor antagonist, on basal PRL, LH, FSH and TSH concentrations, on their response to specific releasing hormones, and on basal and TRH-stimulated levels of thyroid hormones. Neither the basal levels of PRL, FSH, LH and TSH, nor their response to stimulation with appropriate releasing hormone were affected by ranitidine. Basal concentrations of T4 and its levels after TRH stimulation at 40 min (but not at 20, 60 and 120 min) were lower after ranitidine treatment (P less than 0.05); basal and stimulated T3 and rT3 were unaffected. These results could suggest a possible role of histamine in thyroxine regulation but further studies are required.

Adult↗

Abnormal control of growth hormone secretion by opiate systems in acromegalic patients: a study with naloxone and 2-Br-alpha-ergocryptine (CB 154).

The present study was undertaken with the aim of exploring the role that opiate systems may have in neuroendocrine control in acromegaly. The effects of naloxone (0.4 mg, i.m.), of 2-Br-alpha-ergocryptine (CB154, 2.5 mg, p.o.) and of the interaction between CB154 and naloxone on growth hormone (GH) and prolactin (PRL) secretion were studied in 11 acromegalic patients. CB154 reduced both GH and PRL serum levels, naloxone only GH serum levels. The latter effect deserves further study aimed at a possible new therapeutic approach to GH hypersecretion observed in acromegaly. Naloxone also interfered with the lowering effects of CB154 and GH and PRL serum levels, pointing to the existence of an interaction between dopaminergic and opiate control of GH and PRL secretion in acromegaly.

Acromegaly↗

[The significance of the radioimmunological of serum myoglobin in myocardial infarction].

The Authors carried on a study in a group of 31 patients with acute myocardial infarction (AMI). The controled particularly the following dates: myoglobinemia (MG) with RIA and myocardial necrosis enzymes with traditional methods. Blood has been drawn from patients every 90 min, during the first 8 h of admission and every 4 h during the following 4 days. Important variations of MG have been detected in 80.6% of cases. These is an early increase in MG (within 4 h in 25.8% and within 8 h in 45.1% of cases) and normal values are reached in a time not longer the 72 h. The maximum value is reached in a shorter time than that creatine phosphokinase (CPK). We can therefore confirm that MG is a useful data in the early diagnosis of myocardial infarction in preenzymatic stage.

Adult↗

[Critical analysis of the radioimmunological methods of determining creatine kinase isoenzyme MB (CK-MB), myoglobin (MG) and of LDH (H4) in ischemic cardiopathy].

We have studied 135 subjects of whom 100 were normal individuals; 10 with diagnosis of acute myocardial infarction (AMI); 10 with angina pectoris; 10 undergoing cardiac catheterism; 5 who underwent open heart surgery. To verify the radioimmunoassay usefulness of CPK cardiac isoenzyme (CK-RIA), of lactate dehydrogenase [LDH (H4)], of myoglobin (MG) in the diagnosis of ischemic disease, we have determined for serum samples: LDH (H4) by radioimmunoassay and HBDH by biochemical assay; CK by biochemical assay; CK-MB by biochemical and radioimmunological assay; MG by radioimmunoassay. The results indicate MG as a sensitive marker for the diagnosis of AMI. In fact serial serum determinations in patients with AMI showed myoglobin levels in 60% of the cases within 1 h after the onset of pain. The CK-RIA is the most sensitive test to evaluate infarct size and LDH (H4) conditioned by the amount of intracellular lactate is an useful test to evaluate myocardial anoxia.

Acute Disease↗

Results with six "kit" radioimmunoassays for primary bile acids in human serum intercompared.

We examined six radioimmunoassay procedures for measuring primary bile acids in human serum (two 3H-labeled and four 125I-labeled). A significant (p < 0.01) correlation was observed between measurements in the assay both for cholic acid and chenodeoxycholic acid, at low and high concentrations of serum bile acids. All kits were acceptable with respect to accuracy, precision, stability, and analytical recovery. All six procedures gave similar results for chenodeoxycholic and cholic acid in sera of 80 healthy subjects; the agreement was also close when the two primary bile acids were compared with their sum in serum. Normal values ranged from 0.4 to 2.5 mumol/L for conjugated chenodeoxycholic acid and from 0.3 to 1.5 mumol/L for conjugated cholic acid. The 125I assays do not require liquid-scintillation equipment but 125I induces a decrease in the affinity constant of antibody. The sensitivity of the assays was still adequate for measuring bile acids in the serum of healthy fasting persons and liver-disease patients.

Adult↗