Effects of food on plasma catecholamine and gastrin levels in patients with duodenal ulcer and normal volunteers

The effect on adipose tissue blood flow of isoenergetic meals containing different amounts and types of fat

OBJECTIVE

To investigate the factors regulating the increase in adipose tissue blood flow following meals.

DESIGN

Eight subjects were fed three isoenergetic meals; two high-fat meals rich in either saturated or polyunsaturated fatty acids and one low-fat, high-carbohydrate meal.

MEASUREMENTS

Blood samples were taken and adipose tissue blood flow was measured before and for 6 h after the meal. Plasma glucose, insulin, non-esterified fatty acid, total and chylomicron-triacylglycerol and catecholamine concentrations were measured.

RESULTS

Adipose tissue blood flow rose to a peak after all three meals (P<0.05 for each). The three meals stimulated adipose tissue blood flow at similar times. There was a marked and statistically significant similarity in the time course of changes in blood flow and insulin concentrations. In contrast, noradrenaline concentrations peaked later than adipose tissue blood flow (P=0.014).

CONCLUSION

Adipose tissue blood flow may be 'carbohydrate-stimulated' rather than 'fat-stimulated', with insulin having a vasodilatory role in adipose tissue as in skeletal muscle.

Sympathoadrenal activity and psychosocial stress. The significance of aging, long-term smoking, and stress models

Recent studies have indicated that the increase in plasma norepinephrine and sympathetic activity with aging in healthy subjects is largely due to long-term cigarette smoking. In patients who have or have had duodenal ulcer the increase in plasma norepinephrine with age was markedly increased. These patients as a group perceive their lives somewhat more stressful than the general population and they tend to die prematurely due to smoking-associated diseases. These patients may select dysfunctional coping strategies like smoking, which may result in organ pathologies and a compensatory increase in plasma norepinephrine. No close correlation has been established between plasma epinephrine and "ill health." High plasma epinephrine levels may have a deleterious effect on the cardiovascular system in elderly subjects during certain conditions. In a population study, we found, however, that low resting plasma epinephrine levels were associated with an unfavorable survival rate. We speculate that an inadequate response to psychosocial stress and the choice of dysfunctional coping strategies may be more harmful and cause more "ill health" than hypersecretion of stress hormones like epinephrine and cortisol, which has been the traditional view. We suggest that there are different stress states. Stress hormones like epinephrine and cortisol may play a major role during situations like combat, illness, and strenuous exercise. In response to psychosocial stress, dysfunctional coping strategies are, however, largely responsible for harmful effects of stress.

Cardiovascular effects of eating, atenolol and their interaction: beta1-adrenergic modulation does not play a predominant role in the genesis of postprandial effects

1. Eight healthy subjects were investigated on four occasions at least 1 week apart when they either ate a standard 3100 kJ cold meal or fasted. One hour earlier, either 50 mg atenolol or placebo was administered. 2. Eating was followed by prominent changes of systolic cardiovascular function: a rise of heart rate (+7, 95% CI: 4 to 9 beats min(-1)), systolic BP (+5, CI: 1 to 8 mmHg), a drop of diastolic BP (-6, CI:-9 to -3 mmHg), shortening of the pre-ejection period PEP (-11, CI: -13 to -9 ms) and electromechanical systole QS2c (-13, CI: -17 to -8 ms), a rise of the estimated cardiac output CO (+1.3, CI: 1.0 to 1.6 1 min(-1)) and a reduction of the calculated total peripheral resistance TPR (-306, CI: -389 to -222 dyn s cm(-5)). 3. Eating was also followed by an increase of the non-renal clearance of sorbitol (as a measure of hepatic blood flow) and this change was larger than proportional to the increase of CO. The plasma renin activity rose after the meal but the venous plasma noradrenaline and adrenaline concentrations were not affected. 4. The postprandial effects peaked over the first 1-2 h after the meal but remained well detectable up to 4 h after eating. 5. The administration of 50 mg atenolol before the meal reduced the postprandial effects to the same extent as the atenolol effects in the fasting state. This lack of interaction (or mere arithmetic additivity) indicates that the efferent beta1-adrenergic tone does not play a predominant role in the modulation of postprandial cardiovascular changes.

Gastrin, somatostatin and oxytocin levels in patients with functional disorders of the gastrointestinal tract and their response to feeding and interaction

Twenty-four individuals with functional disorders of the gastrointestinal tract participated in the study. Symptoms from the upper and lower gastrointestinal tract were recorded by means of a self-administered questionnaire before, 3 months and 3 yr after participation in group therapy. Blood was sampled from the patients while they were subjected to three different provocations (a friendly greeting, a food stimulus and a stress stimulus). Ten subjects without gastrointestinal symptoms participated in an identical experiment. Gastrin, somatostatin and oxytocin levels were measured with radioimmunoassay. Both gastrin and somatostatin levels were influenced by the provocations and by the greeting and the stress stimulus in particular. In principle, the controls tended to react with a parasympathetic response pattern following the interactive stimuli, whereas the individuals with functional disorders of the gastrointestinal tract reacted with an activation of the sympathetic nervous system. Somatostatin levels were significantly higher and oxytocin levels lower in patients than in controls and gastrin levels tended to be higher in patients than in controls. Most individuals reported both gastric as well as intestinal symptoms. Gastrin levels correlated positively with total symptom level and somatostatin levels with intestinal symptoms scores reported by the patients.

Postprandial changes in supine and erect heart rate, systemic blood pressure and plasma noradrenaline and renin activity in normal subjects

The haemodynamic effects of a standard meal were assessed in a balanced cross-over study in eight normal fasting subjects, investigated under conditions applicable to many drug tests. Both the supine and erect diastolic blood pressure were reduced on average by 10 mmHg over the 4 h following the meal. The supine systolic pressure was increased on average by 2 mmHg, a difference of no biological relevance. Erect systolic blood pressure was not affected by eating. Supine heart rate was slightly but significantly increased, but the erect heart rate did not change. Postprandial plasma renin activity was increased. Venous plasma noradrenaline levels in the supine position were not affected by eating and after standing erect, and immobile for 5 min they were only slightly and not-significantly increased. A food-induced vasodepressor response combined with baroreceptor resetting is considered to have occurred in this population. The changes had a gradual onset, reaching their maximum about 2 h after eating and they were still evident after 3 h. Eating should be considered as an important potential source of bias in cardiovascular studies.

Basal and food-stimulated levels of gastrin and pancreatic polypeptide in non-ulcer dyspepsia and duodenal ulcer

Basal and food-stimulated levels of gastrin and pancreatic polypeptide (PP) were studied in 86 patients with non-ulcer dyspepsia (NUD), defined as chronic or recurrent epigastric pain without anatomical antecedents and without concomitant symptoms of irritable bowel. Thirteen patients with endoscopically confirmed duodenal ulcer disease (DU) and 13 healthy subjects constituted the reference groups. The mean basal gastrin concentration was moderately but significantly (p less than 0.05) higher in the NUD group than in the reference groups (24.3 +/- 1.6 (SEM) pmol/l in NUD, compared with 15.0 +/- 1.5 and 13.6 +/- 1.0 pmol/l among DU patients and healthy subjects, respectively). The well-established postprandial hypergastrinemia in duodenal ulcer patients could be confirmed in this study, and their gastrin response to food was significantly (p less than 0.01) greater than the responses observed both in healthy subjects and in NUD patients. The two latter groups did not differ significantly with regard to gastrin increments, but there was a tendency towards greater increases in the NUD group. A significantly (p less than 0.05) enhanced PP response to the test meal was observed among the DU patients, whereas the response pattern in NUD was closely similar to that in healthy subjects.

Plasma norepinephrine is abnormal in patients with duodenal ulcer. The significance of age

Previous studies indicate that the forearm venous plasma norepinephrine (NE) concentration is abnormally high in patients with duodenal ulcer. The aim of the present study was to examine the relationship between age and plasma NE concentration in patients with duodenal ulcer and controls. Eleven male patients with duodenal ulcer and 12 male control subjects were examined. Plasma NE concentration was approximately twofold greater in duodenal ulcer patients in both the resting seated position and during exercise than values obtained in controls (2 p less than 0.02, less than 0.05). There was a strong correlation between plasma NE and age in patients with duodenal ulcer but not in controls (r = 0.69, 2 p less than 0.05). Our results suggest that the increase in plasma NE with age is greater in patients with duodenal ulcer than in normal healthy subjects or in patients with minor surgical diseases. Patients with duodenal ulcer may have a higher functional age than healthy subjects.

Influence of food intake on concentrations of plasma catecholamines and cortisol

Plasma concentrations of epinephrine, norepinephrine, dopamine and cortisol were determined in four healthy volunteers--resting completely in bed--before and after food intake. Meals were provided at 17.00 h on the first day and at 12.00 h on the second day of the test. Blood samples were drawn every 15 minutes. Epinephrine, norepinephrine, dopamine, and cortisol showed a clear dependence on food intake. After the meals plasma concentrations of the four analytes showed rises, which were more pronounced after lunch at 12.00 h than after dinner at 17.00 h. An increase of epinephrine was observed shortly before meal-times; this could be caused by physiological adaptation to the usual rhythm of food intake and reflex response to expectation of the meal.