Effects of somatostatin on the insulin- and gastric inhibitory polypeptide-stimulated fatty acid esterification in rat adipose tissue

Relations exist between insulin, somatostatin (S) and gastric inhibitory polypeptide (GIP) for the reciprocal control of their secretion but also for their role in lipid metabolism. In the present experiment, we studied the effects of somatostatin on fatty acid incorporation into epididymal adipose tissue (FIAT) of Wistar rats when it was stimulated by insulin and GIP. Cyclic somatostatin-14 was used at physiological (S1 : 50 pg/ml, S2 : 200 pg/ml) and supraphysiological (S3 : 666 pg/ml) concentrations whereas insulin and GIP were used at postprandial levels (100 microU/ml and 2 ng/ml respectively). Results were expressed as percent of basal incorporation (without any hormones). Somatostatin inhibited basal FIAT at all concentrations and totally abolished the insulin-stimulated FIAT (from 106.4 +/- 2.3 per cent with insulin alone to 92.6 +/- 2.5 per cent with S3, P less than 0.001). GIP enhanced the insulin-stimulated FIAT from 106.4 +/- 2.3 per cent to 113 +/- 3.0 per cent (P less than 0.01). On the contrary, when somatostatin was added with GIP and insulin, FIAT decreased to 102.3 +/- 2.5 per cent for S1 (P less than 0.01) and to 98.2 +/- 2.6 per cent for S3 (P less than 0.001). These results indicate that somatostatin totally inhibits the fatty acid esterification induced by insulin and in the same proportions that induced by insulin associated with GIP. Somatostatin is not only an inhibitor of the secretion of these hormones but also a regulator of their biological action in adipose tissue.

The effects of gastric inhibitory polypeptide and insulin on fatty acid uptake in adipose tissue are not mediated through cyclic AMP in lean and obese Zucker rats

To determine the mechanism by which gastric inhibitory polypeptide (GIP) and insulin stimulate the in vitro fatty acid incorporation into adipose tissue (FIAT), we measured the cyclic AMP variations and FIAT in epididymal fat pads of lean Fa/-- and obese fa/fa Zucker rats. GIP was used at 1, 2 and 4 ng/ml and insulin at a concentration of 100 microU/ml. There was no significant variation of cAMP when FIAT was stimulated either by GIP, either by insulin or by both hormones. There was no correlation at all between FIAT increases and cAMP levels. We conclude that GIP and insulin act through cAMP independent mechanisms in adipose tissue. The modification by GIP of insulin binding to adipocytes or an easier passage of fatty acids through the membrane could constitute alternative solutions for such mechanisms.

The reduction in microfilariae loads in the skin and eye after nodulectomy in Ecuadorian onchocerciasis

This study is concerned with the relationship between palpable onchocercal nodules and Onchocerca volvulus microfilarial loads in the skin. The number of microfilariae in clinically normal skin decreases as the distance from the nodule increases. Surgical removal of nodules reduces the microfilarial loads in 40 of 46 patients studied over a period of five months, with an average reduction of 65.4% of the prenodulectomy microfilarial load at the iliac crest. Complete elimination of detectable parasites was seen in some patients. Five individuals had increased microfilarial loads, all of which had developed new palpable nodules. Also, nodulectomy had a significant effect on ocular tissue, reducing the levels of parasites in the cornea and anterior chamber in 10 of 15 patients observed with no new nodules developing during the observation period. Both dermal and ocular clinical manifestations of onchocerciasis were reduced in a proportion of the patients. These parasitological and clinical findings provide evidence that nodulectomy is a beneficial procedure to O. volvulus infected patients in Ecuador by reducing both microfilarial loads and the degree of pathology.

A transformer-coupled double-resonant probe for NMR imaging and spectroscopy

A new type of double-resonant coil which takes advantage of the properties of a radio-frequency transformer is described. Two concentric loops are wound in close proximity to yield a high mutual inductance. The primary side is tuned to 34 MHz for 31P and the secondary side is tuned to 85 MHz for protons. A single lead allows program control over frequency without the need to rearrange cabling. Proton and phosphorus spectroscopy are made possible over essentially the same volume of interest without the need for repositioning the sample.

Protein-energy malnutrition in pregnant rats improves the adaptation of the endocrine pancreas in malnourished offspring and induces insulin resistance after rehabilitation

1. In developing countries, malnutrition begins during pregnancy and lactation. Glucose intolerance is a problem of importance during protein-energy malnutrition (PEM). We therefore studied glucose homeostasis in rats weaned from undernourished mothers. 2. On weaning, 156 male Wistar rats, born from deprived mothers (75 g casein/kg diet), were fed ad lib on either a balanced diet (180 g casein/kg; group DR), or a protein-deficient diet (50 g casein/kg; group DD). At seven time intervals (weeks 0, 1, 3, 5, 8, 16 and 23) twelve rats were weighed, fasted overnight and then decapitated. Blood glucose, plasma insulin (IRI) and glucagon (IRG) levels and pancreatic insulin and glucagon contents were determined. 3. In DR and DD rats blood glucose, which was normal at weaning, dropped in the 1st week and then increased slowly. DR rats were hyperglycaemic from week 16. IRI continually increased during the experiment from near-normal values to hyperinsulinic levels in DR rats; in group DD, it remained stable until week 8 before increasing. IRG, which was very low at weaning, increased to normal levels in the 1st week in group DR; in group DD, it fell slightly during the study. Pancreatic hormone contents were much higher than after normal pregnancy and lactation. 4. We compared these results with those of a previous study with rats born from normal mothers: at weaning in the second experiment the rats were already well adapted to malnutrition. The plasma ratio IRI:IRG in DD rats showed two phases of adaptation: weeks 0-5 when glucose homeostasis did not change and weeks 5-23 when it became increasingly normal. At the end of the experiment DR rats still had a lower body-weight than normal rats but were insulin-resistant.

Effect of parental malnutrition on enzyme content of rat pancreas

The aim of this study was to assess in rat pups the influence of protein diets ingested by their mothers during gestation and lactation on the enzyme content of the pancreas of the offspring. Rat pups born of either well-nourished mothers or of mothers fed a diet moderately restricted in protein (9% casein w/w) were studied. After weaning, the pups were fed on one of three diets: a well-balanced diet, a 5% casein diet (protein restricted), or a well-balanced diet of a similar caloric value as the protein-restricted diet (pair-fed rat pups). The pups were sacrificed after intervals of one to 25 weeks after weaning. The results showed that the enzyme content of the pancreas increased progressively with time in pups born of malnourished mothers, particularly in pups fed the protein-restricted diet. This suggests prolonged maturation of the pancreas. Pups fed the 5% casein diet had a decreased amylase content per milligram of DNA but not of other enzymes. Malnutrition in the mother increased the ratio of enzymes to DNA and the total pancreatic enzyme content at different times after weaning, indicating that maternal malnutrition had a prolonged effect on the pancreatic enzyme content of the pups' pancreas. This mechanism could play a role in the pathogenesis of tropical chronic calcific pancreatitis in man and explain some of the geographic differences in the incidence of the disease.

Nutrient homeostasis: long-term interrelations between pancreatic hormones, blood glucose and dietary wheat bran in men

Postprandial plasma somatostatin (SLI), pancreatic glucagon, insulin (IRI) and blood glucose (BG) were measured at 0, 30, 60, 120 and 180 min after a test meal in 10 healthy men before and after 1, 3 and 7 wk of ingestion of a balanced diet supplemented daily with 20 g wheat bran. BG response to the test meal was significantly and consistently lower after the first week of consuming bran, with a maximum drop after 3 wk. After 1 wk of bran, when compared with the prebran values, SLI secretion was decreased, and glucagon response was significantly enhanced at 120 and 180 min after the meal. IRI secretion did not change significantly until the third week. After consuming bran for 7 wk, postprandial SLI concentrations returned to prebran values, and glucagon levels were not significantly different from those of the first meal. IRI during the fourth test meal (after 7 wk of bran consumption) was significantly higher than after the third meal (after 3 wk of bran ingestion), at 60 min and at 120 min. BG levels remained low. Chronic bran ingestion was therefore associated with an improved glucose tolerance. Its effects on pancreatic hormones varied with time for each hormone, and somatostatin was the only one to return to the prebran values.

Trisomy 14 mosaicism in a 2 year old girl

Trisomy 14 mosaicism with 6% trisomic cells in blood and 16% in skin fibroblasts was found in a 2 year 2 month old girl with mild psychomotor retardation, craniofacial dysmorphism, pectus carinatum, curved fifth fingers, retarded bone age, and signs of an ASD. These findings are consistent with the previously reported cases of trisomy 14 mosaicism and support the suggested existence of a distinctive syndrome. Non-disjunction studies showed that the extra chromosome 14 originated from either a second paternal meiotic error or an early mitotic error.

Effect of exchange of ham for boiled egg on plasma glucose and insulin responses to breakfast in normal subjects

Blood glucose (BG) and plasma insulin (IRI) were measured during two breakfasts different only by the nature of proteins--egg (E) or ham (H)--in eight normal subjects. Compared with H, E led to a flattened BG response at 30, 40, and 50 min and to a sustained BG from 150 to 240 min. Integrated BG response was not significantly different between E and H. After E, the IRI response decreased at 90 min and 120 min (P less than 0.05). Integrated IRI response with E was significantly smaller than with H (P less than 0.025). The reasons for the effect of E ingestion on BG are not obvious; pancreatic and/or intestinal mechanisms may be involved. It is suggested that greater consideration be given to the protein composition of the test meals when they are used in studies of glucose homeostasis.

Long-term influence of a wheat-bran supplemented diet on secretion of gastrointestinal hormones and on nutrient absorption in healthy man

Responses of gastric inhibitory polypeptide (GIP), gastrin and vasoactive intestinal polypeptide (VIP) to a test meal and also nutrient absorption were measured in five healthy men before and after 1, 3 and 7 weeks of daily ingestion of 20 g of wheat bran added to a normal balanced diet. Basal levels of the three hormones were not affected by bran ingestion. Bran ingestion induced a progressive decrease of GIP response to the test meal which became significant after 7 weeks at 30 min (373.9 +/- 71.4 vs 231.1 +/- 47.8 pg/ml, mean +/- s.e.m., P less than 0.05) and at 180 min (389.4 +/- 43.9 vs 262.2 +/- 37.9 pg/ml, P less than 0.01). Gastrin release did not change except for a slight but not significant decrease after 3 weeks. There was no VIP secretion after meal ingestion and addition of bran caused no change. Blood glucose response decreased with time with the greatest effects during the third week with fibre at 30 min (5.00 +/- 0.50 vs 7.38 +/- 0.05 mmol/l before bran), and at 60 min (3.88 +/- 0.34 vs 5.94 +/- 0.27 mmol/l before bran, P less than 0.05). Wet and dry weight of faeces increased by at least 60 per cent from the first week with bran onwards. Faecal nitrogen and fat also increased from 1.77 +/- 0.16 to 2.44 +/- 0.13 g/d for nitrogen (P less than 0.02) and threefold for fat (from 3.78 +/- 0.58 to 10.35 +/- 0.67 per cent dry weight, P less than 0.005) at the third week. Fat and nitrogen contents remained higher until the end of the experiment.(ABSTRACT TRUNCATED AT 250 WORDS)

Progressive adaptation of the endocrine pancreas during long-term protein deficiency in rats: effects on blood glucose homeostasis and on pancreatic insulin, glucagon and somatostatin concentrations

Blood glucose, plasma insulin and glucagon, as well as pancreatic insulin, glucagon and somatostatin contents, were measured in control (C group, 18% casein), deprived (D group, 5% casein) and pair-fed (PF) rats at seven intervals during 23 wk after weaning (wk 0). In C rats, plasma and pancreatic insulin showed parallel variations, in D rats, plasma insulin increased normally until wk 3 after weaning, dropped from wk 3 to 8 and was higher in wk 16 and 23 than in wk 8, while pancreatic insulin increased linearly after a significant drop between wk 0 and 1. Insulin variations in D rats were related to protein deficiency until wk 5, but only to energy deficiency thereafter. Circulating and pancreatic glucagon dropped identically for the three groups until wk 5: its role in adaptation to malnutrition is quite irrelevant, although a dysregulation of its secretion was noted. Protein-energy malnutrition induced an increase of pancreatic somatostatin content that was due to the energy deficiency. On the basis of the insulin-to-glucagon ratio, three phases of adaptation to protein-energy malnutrition appeared. From wk 0 to 3, the metabolic priority was growth, whereas glucose homeostasis was secondary, accounting for the early hypoglycemia. From wk 3 to 8 survival was the main priority. After wk 8, the various biochemical parameters stabilized, and growth was parallel to that of normal animals. Protein-energy malnutrition was responsible for a dissociated adaptation of pancreatic hormones.

Mortality, pathological findings and causes of death in the de Lange syndrome

The mortality of 48 de Lange patients born 1917-82 was found slightly raised compared with the expected number of deaths, and the survival rates appeared to be lowered. No sex differences were observed. The causes of death and the pathological findings were evaluated in 11 patients. Pneumonia was the most frequent cause of death (6 patients). Congenital malformations seemed to be contributory causes of death in 5 patients, the most frequent being congenital heart disease and gastro-intestinal malformations. A wide variety of malformations were found but no consistent macroscopic or microscopic abnormalities could be demonstrated. An incidence figure of 1:50 000 was found for the years 1967-82.

Effect of sucralfate on gastroesophageal reflux in esophagitis

Gastroesophageal reflux was assessed in 18 patients with endoscopically and histologically verified esophagitis, and 15 asymptomatic normal subjects, by a portable receiving system. The qualitative evaluation of the frequency of reflux episodes, normalized mean pH, normalized mean [H+] and the acid clearance rate is found to be indicative of gastroesophageal reflux. Twelve weeks of treatment with sucralfate in an open clinical trial resulted in a significant reduction of gastroesophageal reflux and the elimination of esophageal mucosal damage. Barrett++'s epithelium was found in a rather high proportion and proved to be resistant to treatment. It is suggested that the observed improvement is due to the barrier protecting properties of sucralfate restoring the motor function of the distal esophagus.

Effect of potent antiglucocorticoids on dexamethasone induced enzymes in cultured hepatoma and rat liver cells

The antagonism by 3 synthetic steroids of the induction of tyrosine aminotransferase and tryptophan dioxygenase by dexamethasone were compared in HTC and FAZA hepatoma cells and in isolated liver cells. It was observed: (i) the sensitivity of liver cells to glucocorticoid agonists and antagonists changed in relation to time of culture; (ii) the extent of the inhibitory effect on enzyme induction depends on the nature of the antagonist; (iii) hepatoma cells, especially HTC cells, appeared more sensitive to glucocorticoid antagonism than liver cells.