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Biomedical subjects

R Jorde

Publications and source records attributed to R Jorde.

At least 127 records · Page 7Linked to original sources
PubMed1984

Similar plasma GIP responses in obese and lean subjects after an oral test meal and after intraduodenal stimulation with fat and glucose.

Eight morbidly obese subjects and 12 controls were studied with an oral test meal and a heavy duodenal infusion with fat and glucose. Five of the controls were excluded because of nausea and vomiting after the duodenal stimulation whereas none of the obese subjects noted any discomfort. There was no difference in plasma GIP secretion between the two groups neither after the oral nor after the duodenal stimulation. The present study supports our previous conclusion of an unaltered GIP secretion in obesity.

Adult↗
PubMed1984

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.

Adult↗
PubMed1984

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 0.05) in the MAOsh, which, however, was not significantly elevated when basal-subtracted. MAOpg was unchanged. In contrast to acid, pepsin output was not influenced by stress. The human pancreatic polypeptide (hPP) level in serum increased twofold after the stress. The integrated hPP response induced by modified sham feeding was higher (p = 0.02) after the stress than in the control experiment. The results show that physical stress has separate influence on the gastric secretion of acid and pepsin.

Adult↗
PubMed1984

Fasting and postprandial serum gastrin levels in obese and slim subjects, and the effects of surgical treatment for obesity on serum gastrin levels.

23 obese and 17 control subjects were studied after ingestion of a heavy breakfast, and 11 obese and 11 control subjects were studied after ingestion of a mixed liquid test meal. Five subjects from the latter group were also studied two and six weeks after a jejuno-ileal bypass operation and the remaining six subjects from this group were studied twelve weeks after a stapled gastric partitioning. No significant differences in fasting or postprandial serum gastrin levels were found between the obese and the lean subjects, neither when studied with the breakfast meal nor when studied with the mixed liquid test meal. After the jejuno-ileal bypass operation the serum gastrin levels were not significantly different from the preoperative ones, whereas both the fasting and the postprandial serum gastrin levels were significantly augmented after the stapled gastric partitioning procedure. The group operated on with the latter method was also studied with an insulin test before and after the operation. Similar to that seen after ingestion of the mixed liquid test meal, the serum gastrin levels after the insulin-induced hypoglycemia were significantly higher postoperatively.

Adult↗
PubMed1984

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.

Duodenum↗
PubMed1984

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. One should therefore be careful when evaluating physiological effects of porcine GIP infused intravenously in species other than the pig.

Adult↗
PubMed1984

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.

Adult↗
PubMed1984

Responses of vasoactive intestinal polypeptide, secretin, and human pancreatic polypeptide to glucose during fasting.

The plasma concentrations of vasoactive intestinal polypeptide (VIP) and secretin and the serum concentration of human pancreatic polypeptide (hPP) were measured in nine healthy subjects during a 4-day fast. The fast induced a considerable increase in the concentrations of VIP and secretin but only a small increase in the concentration of hPP. The intravenous infusion of 50 g glucose and the oral ingestion of 50 g glucose temporarily suppressed the high concentrations of VIP and secretin. Conversely, hPP responded with a slight decrease in blood concentration after the intravenous infusion and with a modest increase after the oral ingestion. The study shows that glucose suppresses the high blood concentrations of VIP and secretin during starvation independent of the route of glucose administration. In addition, the results indicate that the blood concentration of hPP is not directly related to the blood glucose concentration during prolonged fasting.

Administration, Oral↗
PubMed1984

Plasma cholecystokinin (CCK) before and after a jejunoileal bypass operation in obese patients with reference to appetite regulation.

Plasma cholecystokinin (CCK) rose significantly after a 15-min liquid test meal in six normal controls and six obese patients, both before and after a jejunoileal bypass operation. Post-prandial rises in the obese patients were virtually unaffected by the operation, and tended to be higher in the obese patients than in the normal controls. It is therefore concluded that hormonal CCK is unlikely to be a mediator of satiety signals from the digestive tract in obese persons.

Adult↗
PubMed1983

Fasting and postprandial plasma GIP values in man measured with seven different antisera.

In the present study GIP was measured with seven different antisera in fasting and postprandial plasma samples from eight healthy subjects. The mean fasting plasma GIP values ranged from 12 to 92 pmol/l, and the mean postprandial GIP values from 35 to 235 pmol/l. All seven antisera recognized three molecular forms of GIP, and none showed any appreciable crossreactivity with other gastrointestinal peptides. However, a remarkable range in crossreactivity, from 78 to 8%, with C-terminal GIP was found. The most likely explanation for the great differences in plasma GIP values measured appears to be differences in crossreactivity with human GIP.

Adult↗
PubMed1983

Insulin and gastric inhibitory polypeptide secretion in young milk-fed and adult goats.

Plasma concentrations of glucose, immunoreactive insulin (IRI), and immunoreactive gastric inhibitory polypeptide (IR-GIP) were studied in six adult and five young milk-fed goats after intravenous or intraduodenal infusions of glucose. Glucose concentrations after intraduodenal infusions were elevated from 3.5 to 4.7 mmol/liter on the average in adult and from 4 to 7 mmol/liter in young goats. Intravenous infusions were given at rates adjusted to mimic very closely the plasma glucose curves after intraduodenal infusions. Plasma IRI increased from 250 to 600 pmol/liter in adult and from 180 to 500-600 pmol/liter in young goats, but no significant differences were observed between intravenous and intraduodenal infusions. Duodenal infusions of glucose did not stimulate the release of IR-GIP in adult or young goats. It is concluded that the goat is lacking the incretin system for rapid disposal of oral glucose loads and that IR-GIP does not participate in regulation of glucose-stimulated insulin release in this species.

Aging↗
PubMed1983

Increased plasma response of gastric inhibitory polypeptide to oral glucose and a liquid meal after prolonged starvation in healthy man.

24 young, military subjects participated in a ranger training course of 5 days' duration with prolonged, heavy physical exercise and sleep deprivation. The subjects were divided into two groups showing either large calorie deficiency or nearly isocaloric status. An oral glucose tolerance test was performed on the subjects on day 5 on the course and in a control experiment 8 weeks after the course. During the course the subjects with negative calorie balance showed augmented integrated glucose-induced gastric inhibitory polypeptide (GIP) response (p less than 0.05) and the plasma concentration of GIP after glucose stimulation was higher at 90 and 120 min during the course than in the control experiment. On the other hand, the plasma GIP levels of the subjects on isocaloric diet changed similarly during the experimental period and the control period. In another experiment 11 healthy subjects were given a meal after an overnight fast and after 5 days of absolute fasting. The 5-day fast provoked higher postprandial plasma concentration of GIP between 60 and 150 min after meal stimulation, and the integrated meal-stimulated GIP response increased (p less than 0.01) after the prolonged fasting. The subjects in both experiments showed glucose intolerance. The insulinogenic index decreased during the training course, but increased during the prolonged, absolute fasting. The study shows that there is a dietary modulation of the GIP response to nutrient stimulation in healthy man and that the augmented GIP release is not attributable to insulin release.

Administration, Oral↗
PubMed1983

Release of plasma pancreatic polypeptide in achlorhydric patients after intravenous infusion of gastric inhibitory polypeptide.

In order to evaluate whether gastric inhibitory polypeptide (GIP) could be responsible for the postprandial fall in serum gastrin previously observed in patients with achlorhydria, 7 achlorhydric patients were given 100 ml Lipomul (66 g triglycerides) on one occasion, and 5 of these patients were later given a 30-min intravenous infusion of porcine GIP in a dose of 1 microgram/kg. Following the Lipomul ingestion, serum gastrin fell significantly, whereas no effect on serum gastrin was seen during the intravenous GIP infusion. A small, but significant release of serum insulin was seen shortly after starting the GIP infusion, together with a significant and more sustained release of plasma pancreatic polypeptide (PP). It is concluded that GIP does not lower the serum gastrin levels in achlorhydric patients, but that GIP might participate in the intestinal phase of the PP release.

Achlorhydria↗
PubMed1983

The effect of insulin-induced hypoglycemia with and without atropine on plasma vasoactive intestinal polypeptide in man.

Plasma vasoactive intestinal polypeptide (VIP) was measured in six healthy male students on 2 separate days after insulin-induced hypoglycemia with and without atropine and on a 3rd day in five of the students after atropine alone. A significant increase in peripheral plasma VIP was observed when atropine was given together with insulin, whereas insulin or atropine alone had no effect on plasma VIP. It is suggested that cholinergic nicotinic receptors may be involved in the increase of VIP after insulin-induced hypoglycemia and that the lack of VIP increase seen after insulin alone may be caused by an inhibitory effect of other gastrointestinal hormones.

Adult↗
PubMed1983

The fasting levels and the postprandial response of gastroenteropancreatic hormones before and after prolonged fasting.

The effect of a prolonged 5-day fast on the blood concentrations of vasoactive intestinal polypeptide (VIP), secretin, human pancreatic polypeptide (hPP), gastrin, and group I pepsinogens (PG I) was studied in 11 healthy subjects. During the fast there was a marked increase in the concentrations of VIP, secretin, and hPP, whereas the rise in the concentrations of gastrin and PG I was less pronounced. Refeeding suppressed the increased concentration of VIP and caused elevated postprandial concentrations of secretin and hPP, whereas starvation did not influence the postprandial release of gastrin and PG I. The study shows that prolonged starvation has a pronounced effect on gut endocrine responses.

Adult↗
PubMed1983

The effect of prolonged strain on serum levels of human pancreatic polypeptide and group I pepsinogens.

Twenty-four young male subjects participated in a 5-day training course with long-term physical exercise (35% of VO2max), calorie supply deficiency (intake of approximately 6300 kJ/24 h, against a combustion of approximately 40,000 kJ/24 h), and severe sleep deprivation (2 h of sleep as a total during 5 days). The subjects were divided into three groups; one group (no. = 7) had no compensation for the stress factors, another group (no. = 8) compensated for the calorie deficiency, whereas a third group (no. = 9) partly compensated for the sleep deprivation. Fasting serum concentration of human pancreatic polypeptide (hPP) and group I pepsinogens (PGI) were measured immediately before the course, every morning during the course, and 8 h after the course. In addition, the serum response of hPP to a test meal was measured on day 3 during the course and in a control study performed 8 weeks later. The fasting serum concentration of hPP showed a two- to three-fold increase during the course in the low-caloric but not in the iso-caloric subjects. The serum concentration of hPP was decreased to pre-course levels after 8 h of rest. The postprandial hPP response was elevated in all the subjects during the course, with a greater increase in the low-caloric subjects than in the subjects with calorie balance. Serum concentration of PGI was 10-30% decreased during the course, and the levels were normalized after 8 h of rest after the course. The study shows that the function of the hPP cell and the chief cell is influenced by prolonged, multifactorial strain.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1983

GIP and insulin responses to a test meal in healthy and obese subjects.

Twenty-three obese and 17 control subjects were studied after ingestion of a heavy breakfast. Blood samples were drawn before and at 30, 60, 90, 120, 150, and 180 min after the start of the meal. The m ean serum insulin level was significantly (p less than 0.02) higher in the obese than in the control group throughout the study, whereas the mean blood glucose concentration was significantly (p less than 0.02) higher in the obese group at 30, 60, and 90 min only. No significant differences between the two groups were noted in fasting or in postprandial plasma GIP, and it appears that hypersecretion of GIP is not responsible for the hyperinsulinemia seen in obesity.

Adult↗