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Summary: We have investigated on eventual relationships existing in men between plasma levels of 17-a-OH-Progesterone (17-a-OH-P) and, plasma levels of Testosterone (T) and on the modifications of these relationships after stimulation of the testicles by HCG (Human Chorionic Gonadotropin). An inverse correlation exists between basal plasma levels of the two steroids and their Δ max (%max increase 96 h after the injection of 5000 I.U. of hCG): r = -06, p 0.01. This suggests that the enzymatic steps of the Δ -4 steroidogenic pathway are rate-limiting for the synthesis of T. The Δ max of the two-steroids are also inversely correlated with the circulating levels of LH (Luteinizing Hormone) (r = -05, -06; p < 0.01) suggesting that the rate-limiting activity of the Δ 4 pathway is under endogenous LH control. A desensitized state of this pathway can be expected in presence of high circulating levels of LH. Similarly to LH also the FSH plasma levels, an index of function of the seminiferous tubules, are inversely correlated with the 17-a-OH-P and T Δ max (r = -0.4, -05; p 0.005) indicating close relationships between tubular and interstitial functions. In men with idiopathic oligozoospermia and high circulating levels of FSH we have found increased 17-a-OH-P/T ratios after hCG. Zusammenfassung: Es wurde eine Untersuchung durchgefuhrt hinsichtlich moglicher Beziehungen zwischen den Plasmawerten von 17-a-OH-Progesteron, den Plasmawerten fur Testosteron und den Modifikationen dieser Beziehungen nach Stimulation der Hoden mit hCG. Danach besteht eine inverse Korrelation zwischen den basalen Plasmawerten der beiden Steroide und ihrem Δ max (% max. Anstieg 96Std. nach Injektion von 5000 I.U. hCG): r = -06, p0,01. Das weist daraufhin, das die enzymatischen Schritte des Δ-4-Abbaues der Steroidogenese begrenzt sind fur die Synthese von Testosteron. Das max der beiden Steroide ist ebenso invers korreliert mit den circulierenden Werten von LH (r = -05, -06; p

A 59-year-old woman with systemic lupus erythematosus was found to have marked hyperglycemia, extreme insulin resistance and abnormally high plasma immunoreactive insulin. Her circulating erythrocytes displayed a dramatic decrease of 125I-labeled insulin binding. Both the whole serum and purified IgG fraction strongly inhibited the binding of radiolabeled insulin to control erythrocytes. These results suggested, although indirectly, the existence of antibodies to insulin receptors in the serum of the patient. To directly investigate this issue, we used an enzyme-linked solid-phase immunoassay which allows the detection and enumeration of lymphocytes secreting antibodies towards insulin receptors. Peroxidase-conjugated anti-human immunoglobulin is used to reveal the binding of antibodies to insulin receptor-coated dishes. We demonstrated that the patient's mononuclear cells, when briefly incubated in Petri dishes with partially purified insulin receptor, were able to secrete immunoglobulins of G class specifically directed to the antigen. Moreover, only a fraction of the whole population of anti-insulin receptor antibodies was directed towards the insulin binding region of the receptor, seemingly corresponding to the auto-antibodies detected with conventional binding-inhibition assay.

We studied 18 newly diagnosed diabetic patients (8 males and 10 females, aged 18–26 years, within 10–120 days from the onset of symptoms) who were submitted for 15 days to intensive insulin therapy performed via subcutaneous insulin infusion (CSII). We investigated some metabolic and immunological parameters in order to identify a possible marker to predict the selection of patients potentially more responsive to CSII treatment for the remission of type 1 diabetes. In accordance with the International Diabetes Immunology Group we considered clinical remission as being the withdrawal of insulin therapy for at least 3 months. In order to assess β-cell function a fasting and post-prandial serum C-peptide, blood glucose and HbA 1c were performed on all patients before, and 3 days after, the discontinuation of CSII. Islet cell antibodies were determined in all sera by indirect immunofluorescence. Analysis of T-lymphocyte subpopulations was carried out before starting the therapy. The following monoclonal antibodies were used: CD4, CD8, CD57, CD25, HLA-DR. The levels of C3 and C4 and serum IgG, IgA and IgM were also evaluated. After CSII, 11 of 18 patients showed remission. At the beginning of the study we observed no major difference in metabolic parameters between the two groups. Interestingly, the patients who exhibited remission presented a statistically higher percentage of positive cells for CD57, HLA-DR and CD25 surface antigens, significantly lower C4 levels and CD 4 CD 8 ratio and significantly higher IgG levels compared with patients who did not show any remission. Our study confirms that CSII may prolong β-cell function and it could suggest that the phenomenon of remission is associated with T-cell activation. The explanation for these findings is still unclear.

In 200 patients suffering from diabetes and in 163 normal controls sweat test for chloride was performed.

Gli AA. hanno valutato le percentuali d'incidenza delle complicanze vascolari in un gruppo di 11 diabetici con mucoviscidosi. Essi hanno osservato che in questi le complicanze vascolari occorrono con una frequenza minore rispetto a quella osservata in un gruppo di 61 diabetici presi come controllo. Vengono discussi i motivi patogenetici di questa minore incidenza.

We have investigated on eventual relationships existing in men between plasma levels of 17-a-OH-Progesterone (17-a-OH-P) and, plasma levels of Testosterone (T) and on the modifications of these relationships after stimulation of the testicles by HCG (Human Chorionic Gonadotropin). An inverse correlation exists between basal plasma levels of the two steroids and their delta max (%max increase 96 h after the injection of 5000 I.U. of hCG): r = -06, p 0.01. This suggests that the enzymatic steps of the delta -4 steroidogenic pathway are rate-limiting for the synthesis of T. The delta max of the two-steroids are also inversely correlated with the circulating levels of LH (Luteinizing Hormone) (r = -05, -06; p less than 0.01) suggesting that the rate-limiting activity of the delta 4 pathway is under endogenous LH control. A desensitized state of this pathway can be expected in presence of high circulating levels of LH. Similarly to LH also the FSH plasma levels, an index of function of the seminiferous tubules, are inversely correlated with the 17-a-OH-P and T delta max (r = -0.4, -05; p 0.005) indicating close relationships between tubular and interstitial functions. In men with idiopathic oligozoospermia and high circulating levels of FSH we have found increased 17-a-OH-P/T ratios after hCG.

Optimal and early control of recent onset, type I diabetes by intensive insulin therapy has been reported to allow insulin withdrawal in about two thirds of subjects treated. We used continuous s.c. insulin infusion (CSII) in the attempt to induce a temporary remission of insulin dependence in 18 newly diagnosed young adult diabetics. After 10 days of optimized glycometabolic control, insulin infusion was stopped and patients were switched to glibenclamide (15 mg/die) plus metformin (1 g/die). Diabetics were considered in remission of insulin dependence when their metabolic control fulfilled the following criteria for at least 3 months: absence of glycosuria, pre- and post-prandial blood glucose ≤ 120 and 180 mg/dl, respectively, HbAlc ≤ 7%. Insulin therapy could be discontinued for periods of over three months in 11 subjects (61%) and for as long as 18 months in one case. Insulin requirement during CSII was slightly higher in non-remitters (NR) than in remitters (R): 0.36–0.64vs 0.26–0.41 U/kg/die. After 24 months from CSII, R still showed lower insulin requirement (0.35–0.42 U/kg/die) than NR (0.55–0.75 U/kg/die). Further, the role of some hormonal and immunologic factors was investigated. Plasma C-peptide and glucagon were measured, fasting and 2h after each meal, both on admission and immediately after CSII, when patients were switched to oral therapy. No difference in hormone levels could be detected on admission, whereas, after CSII, mean post-prandial increase of C-peptide over basal was significantly higher in R than in NR (1.18 ± 0.37vs 0.22 ± 0.16 ng/ml, p

381 glucose intake normal curves were studied according to the Diabetes Data Group new classification in healthy persons between 10 and 80 years in order to assess the influence of the age upon the normal glucose tolerance. Such an influence, which was evident in all the subjects, turned out to be more important in women with respect to me. In fact, males showed an increase, per decade, of about 1 mg/dl in fasting glycemic levels, of about 6 mg/dl at 60', of 4 mg/dl at 120', while in females there was an increase of about 2 mg/dl in fasting glicemic values, of about 6 mg/dl at 60' and of about 5 mg/dl at 120'. No meaningful correlation between age and insulinemic values was found at all considered points, either in males or in females. The reasons of the decreased glucose tolerance with aging and of its different behavior in the two sexes are discussed.

Fibronectin is a high molecular weight alpha-2-glycoprotein. Its peculiar role in the structure of connective tissue, together with its wide involvement in coagulative dynamics, justified the increasing interest for fibronectin in the pathogenesis of diabetic disease and its vascular sequelae. In the present work, we evaluated the levels of plasma fibronectin (PF) in diabetics with and without retinopathy, and studied the possible correlation between the glycoprotein and some hormonal and metabolic parameters, expression of glycometabolic balance. We examined 26 type I and 24 type II diabetics, further divided into retinopathics and not retinopathics, and 43 normal subjects. We did not find any significant difference in PF levels either between normals and diabetics, or between type I and type II patients, or between retinopathics and not retinopathics. PF was significantly correlated to age, both in normals and in diabetics. Diabetic patients showed a significant positive correlation of PF to total cholesterol (r = 0.56; p less than 0.05) and triglycerides (r = 0.36; p less than 0.05). This seems to suggest, although indirectly, the existence of a relationship between the levels of PF and the degree of large vessel involvement. No significant correlation was found with HbA1c, beta-OH, AcAc, lactate, pyruvate, C-peptide, total and free insulin or GH. We further indicated an inverse correlation between PF and plasma glucagon (IRG). Very low levels of PF are commonly associated with high IRG plasma values during acute energy deprivation such as prolonged fasting and ketoacidotic coma. Therefore, PF levels might represent an index of latent to overt energy depletion.

95 obese subjects, 40 diabetics and 22 normal controls were investigated. The weight of all obese subjects was at least 20% higher than the ideal weight. Catecholamine excretion was determined a few days after hospitalization to minimize the influence of environmental changes. Spectrofluorimetric estimation of adrenaline and noradrenaline in the urine was carried out according to the method of von Euler and Lihajko. Statistical analysis of the results showed a significant increase in both adrenaline and noradrenaline excretion in the group of obeses subjects compared with the diabetics. The increased catecholamine excretion may represent the response of the adrenal medulla to the stress of the disease. Such an increase may be responsible for perpheral insulin resistence and hence acts as a diabetogenic factor. The results obtained emphasize the influence of catecholamines on insulin responsiveness, possibly constituting a major contribution to the diabetic state.

The effect of PEBG on respiration and oxidative phosphorilation (succinate as substrate) has been studied in liver mitochondria of rat treated with glucagon. The results obtained indicate that, while glucagon, as reported by others, induce a significant increase of respiration rate in state 3 (+ ADP), PEBG, at pharmachological dose, antagonizes this effect. The conclusion is that PEBG exertes its hypoglycemic activity by inhibiting the gluconeogenic reactions promoted by glucagon. This is strongly evident in diabetic or starwed conditions.

Catecholamines acutely exert a pronounced insulin-antagonistic effect, which is mediated by beta-adrenergic receptors stimulation. Nevertheless, several patients with pheochromocytoma fail to exhibit an overt diabetic syndrome, in spite of steadily elevated plasma levels of catecholamines. This prompted us to investigate a 16 years old male patient, bearing an extra-adrenal pheochromocytoma, who displayed a slightly impaired glucose tolerance to oral glucose tolerance test, whereas fasting and post-prandial blood glucose, as well as glycaemic response to intravenous glucagon, were in the normal range. Peripheral insulin sensitivity, as evaluated by intravenous insulin tolerance test, was slightly decreased. Supine norepinephrine plasma levels were steadily upon 9 ng/ml; plasma insulin, both fasting and post-prandial, was within the normal range. beta-adrenergic receptors density of peripheral mononuclear cells was strongly reduced when compared to controls (0.97 +/- 0.08 vs 2.82 +/- 0.37 fmol/10(6) cells), without any concomitant change of affinity. Insulin binding to circulating monocytes was reduced as well (2.38 +/- 0.27 vs 5.1 +/- 0.4%/10(7) monocytes); insulin receptor affinity was quite normal (1.7 ng/ml) and total receptor number was 9,200 sites/cell. In desensitization experiments, 1 microM isoproterenol caused only a 20% decrease of beta-adrenergic receptors density in the patient's cells (70% decrease in controls). Six months after surgery, all the above modifications of receptor binding, as well as the mild glucose intolerance, were almost completely reversed. Thus, high levels of norepinephrine were able to induce a decrease of both beta-adrenoceptor and insulin receptor binding, together with a marked reduction of in vitro agonist-induced redistribution of beta-adrenergic receptors.(ABSTRACT TRUNCATED AT 250 WORDS)

Pyruvate-dehydrogenase, an enzymatic mitochondrial complex, exists in both inactive and active forms, insulin being the regulating factor of the transformation of a latter into the former. The basal (PDHb) and total (PDHt) activity of this enzyme in adipose tissue mitochondria from obese hyperinsulinemic humans has been found equal to 1014 +/- 459 SD mU respectively. These values are 250% higher than those found in normal subjects (403 +/- 76 SD and 575 +/- 142 SD respectively). Both in normal and obese subjects the PDHb/PDHt percent ratio was equal to about 70. These results show that insulin, undoubtedly hyperactive in obesity, by activating PDH can induce a major synthesis of fat, a high caloric density tissue.

The study was designed to determine eventual correlation in diabetes mellitus between reduced erythrocyte deformability and red blood cells (RBC) cholesterol content. Significantly higher RBC cholesterol amount was found in 11 diabetics (IDDM) than in 13 controls of similar age (45 +/- 10 yrs) (1.30 mg ml-1 packed cells -1 +/- 0.15 SD vs 1.19 +/- 0.10 SD, p less than 0.05). Blood filterability values have been found significantly higher (p less than 0.025) in the diabetics (42.2 +/- 11.5 SD ml sec. -1) than in controls (33.5 +/- 6.0). Flow time of RBC filterability, measured in erythrocyte saline buffered suspension (40% Hct) in order to eliminate interferences from plasmatic factors, showed a closely correlation with RBC cholesterol content (r = 0.86 p less than 0.01). A significant inverse correlation between RBC cholesterol content and serum ApoA1-HDL levels was also observed (r = -0.58, p less than 0.05). Moreover ApoA1-HDL serum values were significantly (P less than 0.01) lower in diabetics (111.8 +/- 10.1 mg/dl) than in controls (126 +/- 6.6 mg/dl). Our data underline the possible involvement of augmented erythrocyte cholesterol in impairing the microhemologic competence of RBC in diabetes mellitus. A possible relation with lower ApoA1-HDL and lecithin-cholesterol-acyl-transferase (LCAT) is examined.

The influence of lactate on human adipocytes lipolysis and the possible relationship between lactate-induced metabolic effects and beta-adrenoceptor binding sites were investigated. beta-sites were identified in membranes with (125I)-cyanopindolol and in intact cells with (125I)-cyanopindolol and (3H)-CGP 12177. Lactate reduced isoproterenol-induced lipolysis in a dose-response fashion and such inhibition became significant only at 16 mmol/l lactate. Exposure of human fat cells to 16 mmol/l lactate significantly reduced beta-adrenoceptors density on crude membranes. When the binding assay was performed on intact cells using (125I)-cyanopindolol at 37 degrees C, the radioligand identified the same number of receptors, regardless of the presence of lactate in the preincubation medium. When (3H)-CGP 12177 was used, it bound to about 35% less receptors in lactate pre-treated cells than in control. Seemingly, at 37 degrees C, because of its lipophilicity, (125I)-cyanopindolol can cross the plasma membrane and bind to intracellular sites whereas, (3H)-CGP 1277, due to its hydrophilicity, identifies surface receptors only. Thus, the present in vitro study provides evidence that high levels of lactate, similar to the concentrations usually achieved in overt lactic acidosis, are able per se to inhibit human lipolysis and to redistribute beta-adrenoceptors from cell surface to a domain not accessible to hydrophilic ligands.