Influence of residual C‐peptide secretion on the arginine vasopressin response to hypoglycaemia and metoclopramide in insulin‐dependent diabetes

Abstract

Arginine vasopressin (AVP) hypersecretion in response to metoclopramide or to insulin-induced hypoglycaemia has been described in type I diabetes mellitus. In the present study, we examined whether residual endogenous insulin secretion may play a role in the control of this abnormal AVP secretory pattern. For this purpose, 21 insulin-dependent diabetic men and 10 age- and weight-matched normal men were tested with MCP (20 mg in an i.v. bolus). On a different occasion, subjects were tested with insulin (0.15 IU kg-1). The diabetic patients were subdivided into C-peptide negative patients (CpN, 11 patients without detectable endogenous pancreatic beta cell activity) (group I) and C-peptide positive patients (CpP, 10 patients with residual endogenous insulin secretion) (group II). Experiments started after optimization of the metabolic status of the diabetic men by 3 days of treatment with continuous subcutaneous insulin infusion. The basal concentrations of AVP were similar in all groups. The administration of MCP induced a striking elevation in plasma AVP levels in the normal controls and in the diabetic subjects of groups I and II. However, the AVP rise was significantly higher in group I and group II than in normal controls. Furthermore, group I diabetics showed higher AVP increments than group II. Insulin induced a similar hypoglycaemic nadir in all subjects at 30 min, even though the diabetic subjects of groups I and II had a delayed recovery in blood glucose levels. The hypoglycaemic pattern was similar in group I and II. Hypoglycaemia induced a striking AVP increase in the normal controls.(ABSTRACT TRUNCATED AT 400 WORDS)

Enhancement of the GH responsiveness to GH releasing stimuli by lysine vasopressin in type 1 diabetic subjects

“…Vasopressin secretion is higher than normal in diabetics ( Milles et al ., 1980 ; Culpepper et al ., 1985 ; Fisher et al ., 1989 ; Chiodera et al ., 1995 , 1997; Coiro et al ., 1995 ); in the light of our present results we might hypothesize that in diabetes mellitus endogenous vasopressin is involved in the mechanism underlying the abnormal stimulatory effect of GH‐RH on GH secretion.…”

“…Subjects without retinopathy were chosen to participate in this study. All diabetics were C-peptide negative, as established in a preliminary study performed as previously described (Wurzburger et al, 1990a, b;Chiodera et al, 1995). Experiments were started after adjustment of insulin therapy (dose, 24 to 47 U/d; mean, 32 U/d of the intermediate duration monocomponent insulin plus short-acting monocomponent insulin, given together once or twice daily), which remained unchanged during the period of this investigation.…”

Influence of residual insulin secretion and duration of diabetes mellitus on the control of luteinizing hormone secretion in women

“…Previous studies have reported impaired LH responses to Gn-RH in CpN but not CpP patients with short-term (3 years) diabetes mellitus [8]. This phenomenon is part of a general abnormality in hypothalamic, anterior and posterior pituitary function (for review see Refs 8,[10][11][12][15][16][17] observed in CpN diabetic patients. The present results confirm these observations and show that a similar impairment affects naloxone-induced LH secretion.…”

“…Eleven subjects in group 1 (mean age Ϯ SE 29·8 Ϯ 1·4 years) and 11 subjects in group 2 (mean age 31·1 Ϯ 1·5 years) were CpP, whereas 11 subjects in group 1 (30·4 Ϯ 1·6 years) and 11 subjects in group 2 (32·0 Ϯ 1·8 years) were CpN. The inclusion criteria for CpP or CpN groups were decided by preliminary studies according to previous reports [8][9][10][11][12]. None of the diabetic and control subjects was affected by major affective disorders as determined by the Hamilton Depressive Rating Scale [13].…”

Abnormal effect of cigarette smoking on pituitary hormone secretions in insulin‐dependent diabetes mellitus

“…In fact, elevated diurnal and sleep related GH secretion (Johansen & Hansen, 1969;Molnar et al, 1972;Press et al, 1984;Vigneri et al, 1976;Yde, 1970;Wurzburger et al, 1990a;Guistina & Wehrenberg, 1994) and exaggerated GH responses to physical exercise (Hansen, 1970;1971;Coiro et al, 1990;Wurzburger et al, 1990b) and pharmacological stimulation with arginine infusion (Burday et al, 1968;Coiro et al, 1990) have been described. In addition the secretory patterns of other counterregulatory hormones such as corticotrophin (ACTH)/cortisol (Cameron et al, 1987;Coiro et al, 1995b;Roy et al, 1990Roy et al, , 1993 and arginine vasopressin (AVP) (Fisher et al, 1989;Milles et al, 1981;Culpepper et al, 1985;Chiodera et al, 1995;Coiro et al, 1995a;Zerbe et al, 1985) appear to be altered in diabetic patients.…”