Haemodynamic effects of high doses of insulin during acute left ventricular failure in dogs.

Haemodynamic effects of pharmacological doses of insulin during acute ischaemic heart failure were studied in 8 dogs. Severe depression of left ventricular function was induced by the injection of 50 micron plastic microspheres into the left main coronary artery. This was demonstrated by a significant increase in left ventricular end-diastolic pressure and a significant decrease in the maximum rate of left ventricular pressure rise (LVdP/dtmax), stroke volume and cardiac output.

A systematic approach to the preparation of 125I-labeled gastrointestinal regulatory peptides with high specific radioactivities.

A systematic approach is outlined for the preparation of a whole series of immunoreactive 125I-labeled gastrointestinal regulatory peptides with high specific radioactivities. In our hands, the theoretically superior Iodo-gen method has no more to offer than the harsher chloramine-T method in the iodination of secretin, vasoactive intestinal polypeptide, gastric inhibitory polypeptide, and motilin; whereas the gentler Iodo-gen method has to be used to obtain fully immunoreactive cholecystokinin39 (CCK39) and Tyr1-somatostatin tracers. By applying the iodination mixtures on a Sephadex G-15 or a Sephadex G-10 column followed by an SP Sephadex C-25 column--being eluted under so-called 'finite adsorption equilibrium' between the peptides to be purified and the adsorbent--highly purified tracers are obtained with unusually high specific radioactivities.

Release of gastrointestinal hormones in cardiodepressive shock.

In previous studies increased plasma levels of vasoactive intestinal polypeptide (VIP), somatostatin and pancreatic polypeptide (PP) were demonstrated in a porcine endotoxin shock model. Unchanged levels of gastric inhibitory polypeptide (GIP) and secretin point to a specific shock reaction of peptide release and not to a diffuse mucosal leakage. A porcine model of cardiodepressive shock was developed to enable discrimination to be made between a general low-flow state and endotoxin reaction.

What are 'physiological' plasma GIP levels in man after intravenous infusion of porcine GIP?

Six healthy subjects were given a standard breakfast on one occasion and an intravenous infusion of porcine GIP in a dose of 1.0 microgram . kg-1 .

Effects of atropine on GIP-induced insulin and pancreatic polypeptide release in man.

Eight fasting students were given an infusion of porcine gastric inhibitory polypeptide (GIP) and glucose with or without atropine on two separate days. Mean serum insulin levels increased significantly and similarly on both occasions, indicating that both the glucose- and GIP-induced insulin release is unaffected by atropine. Plasma pancreatic polypeptide (PP) rose significantly during the GIP infusion on the day without atropine, suggesting a role for GIP in the intestinal phase of the PP release.

Effects of intravenously infused porcine GIP on serum insulin, plasma C-peptide, and pancreatic polypeptide in non-insulin-dependent diabetes in the fasting state.

Eight fasting patients with non-insulin-dependent diabetes (NIDD) and six healthy controls were given an intravenous infusion of porcine gastric inhibitory polypeptide (GIP). During the GIP infusion mean plasma pancreatic polypeptide level increased significantly in both groups, whereas the mean serum insulin level increased in the NIDD group only, indicating a more important role for GIP in these patients than in healthy subjects.

Effect of intravenously infused porcine GIP on serum insulin in obese and lean subjects studied with the hyperglycemic clamp technique.

To ascertain whether an altered sensitivity to gastric inhibitory polypeptide (GIP) in morbidly obese subjects can play a role in the postprandial hyperinsulinemia seen in this condition, eight obese and eight control subjects were studied with an intravenous infusion of porcine GIP. The blood glucose was maintained at 4 mmol/l above the basal level by a hyperglycemic clamp technique. Although the mean serum insulin level was higher in the obese group throughout the study, the shapes of the serum insulin curves were almost identical in the two groups after the GIP infusion.

Protein-binding of secretin in human plasma.

Protein-binding of endogenous plasma secretin and of 125I-labelled secretin incubated with charcoal-treated plasma examined by gel filtration on a Sephacryl S-200 Superfine column (16 X 980 mm) showed that secretin in plasma appears both to be bound to at least two different plasma proteins where albumin appears to be the major binding protein, and also to occur as a free molecular form. In addition, protein-binding studied by incubating 125I-labelled secretin with charcoal-treated plasma under various conditions followed by charcoal separation of bound from free label indicated the presence of more specific secretin-binding sites on the plasma proteins with an avidity comparable to that otherwise reported for albumin as a binding protein. The protein-binding of 125I-labelled secretin was optimal or reached equilibrium after 2 days incubation at 20 degrees C and first after 8 days incubation at 4 degrees C.

Changes in plasma levels of gastrointestinal regulatory peptides during hemorrhagic shock in pigs.

In an experimental study of hemorrhagic shock, systemic and portal plasma levels of vasoactive intestinal polypeptide (VIP), somatostatin, pancreatic polypeptide (PP), gastric inhibitory peptide (GIP), secretin and insulin were measured with radioimmunoassay methods. Six pigs (30-40 kg) in general anesthesia were submitted to severe hemorrhage (approximately 30% of the blood volume) for 60 min, followed by reinfusion of the shed blood. Aortic blood pressure and cardiac output fell significantly during the shock state and recovered after the infusion.

Fasting and postprandial GIP values in pigs, rats, dogs, and man measured with five different GIP antisera.

Fasting and postprandial blood samples were collected from pigs, rats, dogs, and man and the gastric inhibitory polypeptide (GIP) immunoreactivity measured with five different antisera. The mean GIP values in rats, dogs, and man varied considerably, depending on the antiserum used, whereas all the antisera recorded fairly similar GIP values in pigs. These findings demonstrate immunological differences between rat, dog, human, and porcine GIP.

The effect of insulin-induced hypoglycemia and atropine on serum cationic trypsin-like immunoreactivity in man.

In seven healthy volunteers insulin-induced hypoglycemia caused a significant rise in free serum cationic trypsin-like immunoreactivity (CTLI), which could be blocked by atropine. Atropine alone significantly decreased the serum CTLI level. The inhibitory effect of atropine was augmented by insulin, which appears to be a peripheral inhibitor of the CTLI release from the pancreatic acinar cells.

The effect of physical stress on gastric secretion and pancreatic polypeptide levels in man.

Twelve healthy subjects were exposed to a 4-day period of hard physical exercise, calorie supply deficiency, and severe sleep deprivation. The basal acid output (BAO), the sham-feeding-induced acid output (MAOsh), and the pentagastrin-stimulated acid output (MAOpg) were measured immediately after this stress period and in a control experiment performed several weeks later. The stress induced a threefold increase in the median BAO and an increase (p less than 0.

Effects of a gastric partitioning operation for morbid obesity on the secretion of gastric inhibitory polypeptide and pancreatic polypeptide.

Nine morbidly obese subjects were studied with a test meal before and 3 months after a gastric partitioning operation. After the operation the postprandial release of plasma gastric inhibitory polypeptide was significantly increased, the plasma pancreatic polypeptide release was similar, and the serum insulin release significantly reduced as compared with the preoperative values.

Radioimmunoassayable plasma motilin in man. Secretagogues, insulin-induced suppression, renal removal, and plasma components.

In normal humans, significant motilin increases were found after meal ingestion, intraduodenal infusion of fat, and intraduodenal infusion of physiological HCl doses. Only a non-significant plasma motilin increase was found in response to intraduodenal infusion of cattle bile. Plasma motilin decreased significantly after an intravenous insulin injection.

Postprandial response and diurnal variation of serum cationic trypsin-like immunoreactivity in man.

In eight healthy volunteers a standard test meal caused an early, transient, but significant increase in serum cationic trypsin-like immunoreactivity (CTLI). Serum CTLI was studied for 24 h in another six healthy volunteers who had four regular meals and performed their usual activities. It showed a diurnal variation with significantly higher values in the late evening and early night than the initial morning value.

Radioimmunoassay of cationic trypsin-like immunoreactivity in man.

The present paper describes the preparation of human cationic trypsin and of a stable and fully immunoreactive 125I-labelled tosyl-lysine chloromethyl ketone (TLCK) cationic trypsin by a modified chloramine-T method with a high specific radioactivity; the production of an avid and specific rabbit cationic trypsin antiserum; and a sensitive, precise, and specific radioimmunoassay method enabling measurements of fasting serum trypsin-like immunoreactivity (CTLI) in the low ng/ml range in normals; the significant rise in serum CTLI in patients with normal pancreatic exocrine secretion; and the absence of any rise in patients with severely reduced pancreatic exocrine secretion after intravenous injection of secretion; a markedly elevated fasting serum CTLI level in patients with acute pancreatitis; fasting CTLI in duodenal juice; and separation of CTLI in one minor and one major molecular component in fasting serum.

Somatostatin release and plasma molecular somatostatin components in man.

The present paper describes a sensitive, precise and specific radioimmunoassay method for measurements of plasma somatostatin; significant rises in plasma somatostatin following a test meal, intraduodenal infusion of fat and HCl, and intravenous injection of insulin; and separation of immunoreactive plasma somatostatin into two components probably representing bound and free molecular forms of somatostatin both in fasting and postprandial human plasmas.

Effects of synthetic porcine GIP on the PP release in healthy subjects.

Six healthy subjects were given 30 min intravenous infusions of synthetic porcine GIP in doses of 0.52, 1.04 and 1.