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Biomedical subjects

K D Buchanan

Publications and source records attributed to K D Buchanan.

At least 163 records · Page 9Linked to original sources
PubMed1985

The effect of oral alcohol on gastroenteropancreatic hormones in volunteers.

This study has examined changes in gastrointestinal hormones induced by alcohol. Ten normal volunteers consumed an orange and carbohydrate-containing drink on two separate occasions, with and without 50g alcohol. There was a significant hyperglycaemia associated with alcohol ingestion but no difference was noted in insulin or gastric inhibitory polypeptide in the two groups. Gastrin release was stimulated by alcohol but pancreatic polypeptide release and N-terminal glucagon release were both suppressed by alcohol. There was no difference in release of secretin or C-terminal glucagon in either group.

Administration, Oral↗
PubMed1984

Physiological circulating levels of secretin-like immunoreactivity in the human do not stimulate free fatty acid production.

An in vivo study was carried out to establish whether infused secretin, which achieves physiological levels of secretin-like immunoreactivity (SLI), promotes lipolysis. Six healthy volunteers received two infusions after separate 8 h overnight fasts. The paired infusions of either 500 ml of normal saline or 150 C.U. of porcine secretin in 500 ml of normal saline were infused at a constant rate of 1.38 ml/min. Venous blood was sampled at 0, 1, 2, 3, 4, 5 and 6 h after the infusion started. Mean plasma concentrations of SLI were significantly higher after infusion of saline with secretin in comparison to infusion of saline alone but remained within the physiological range. Mean serum free fatty acid (FFA) and 3-hydroxybutyrate concentrations rose significantly with time during both infusions but the mean FFA and 3-hydroxybutyrate concentrations did not differ significantly between infusions at each time of assessment. We conclude that a lipolytic role for secretin has not been shown to be of importance in relation to the in vivo rise in FFA concentrations observed in the fasting normal subject.

3-Hydroxybutyric Acid↗
PubMed1984

Predicting the need for insulin therapy in late onset (40-69 years) diabetes mellitus.

A six-year prospective study of 144 newly diagnosed, symptomatic diabetic patients aged 40-69 years showed that 21 (15%) required insulin therapy, commencing 1-61 months after diagnosis. The plasma insulin response to oral glucose was assessed at the time of diagnosis. All 12 patients with very low peak insulin response (less than or equal to 6 mU/l) required insulin therapy. Thirty-six patients had an intermediate insulin response (greater than 6 less than or equal to 18 mU/l); of these, 7 with a mean weight 88% (range 73-96%) of average body weight required insulin, while 29 with a mean weight 117% (range 98-158%) of average body weight, did not. Ninety-six patients had a peak insulin response (greater than 18 mU/l); 2 patients whose weights were 96% and 100% of average body weight, required insulin, while the remainder did not. Consideration of initial body weight and peak insulin response provides a useful prediction of the eventual need for insulin.

Adult↗
PubMed1984

Suppression of somatostatin release by duodenogastric reflux in dogs.

The effect of duodenogastric reflux on systemic and portal venous blood concentrations of somatostatin has been studied in the dog. Duodenogastric reflux suppressed somatostatin concentrations in both systemic and portal venous blood, but this did not occur when bile alone was diverted into the stomach. The suppression was also much less marked when truncal vagotomy accompanied the reflux. These findings suggest that altered somatostatin activity may play a part in the production of the pathophysiological changes occurring in clinical conditions such as peptic ulceration, in which there is an increase in duodenogastric reflux.

Animals↗
PubMed1984

Glucagonoma syndrome demonstrating giant duodenal villi.

A 39 year old man developed an itchy bullous rash in the perineum and on the extremities. Six years later, after giant intestinal villi had been noted at endoscopy, a diagnosis of the glucagonoma syndrome was made. Investigation revealed a large tumour of the pancreatic body and tail. The molecular species of glucagon secreted by the tumour were characterised using the combined purification procedures of immunoaffinity chromatography followed by gel filtration.

Adenoma, Islet Cell↗
PubMed1984

The hormonal changes produced by duodenogastric reflux.

Serum systemic and portal venous blood levels of secretin, vasoactive intestinal polypeptide (VIP), gastric inhibitory peptide (GIP), somatostatin, insulin and pancreatic polypeptide (PP) have been examined in dogs with and without surgically produced duodenogastric reflux. Serum levels of secretin, VIP, insulin and PP showed no change, but reflux caused a significant elevation of GIP levels and a suppression of somatostatin levels in both systemic and portal venous blood.

Animals↗
PubMed1984

The effect of starvation on the gastro-entero-pancreatic hormonal and metabolic responses to exercise. (GEP hormones in starvation and exercise).

Gastro-entero-pancreatic hormonal and metabolic responses to bicycle ergometer exercise for one hour following twelve hours fasting (P1) and 36 hours fasting (P2) were compared. During P1 plasma secretin and blood glycerol increased. Pre-exercise concentrations of plasma C-terminal glucagon-like-immunoreactivity (C-GLI), secretin, blood glycerol, 3-hydroxybutyrate and lactate were higher after 36 hours fasting than 12 hours fasting. During P2 glycerol rose sharply while secretin, C-GLI and 3-hydroxybutyrate remained higher than during P1. A role for secretin and C-GLI in accelerated lipolysis during fasting and exercise is possible.

3-Hydroxybutyric Acid↗
PubMed1983

Failure of fasting to influence the GIP response to oral glucose in non-obese human subjects.

The plasma GIP response to an oral 50 g glucose tolerance test has been compared in eight non-obese human subjects after 12 and 36 h of fasting. Basal plasma GIP and basal plasma insulin concentrations were similar after 12 and 36 h of fasting. Basal blood glucose was lower after 36 h fasting than after 12 h fasting (p less than 0.0125). After 36 h fasting the oral glucose tolerance test stimulated higher blood glucose concentrations at 60, 90 and 120 min (p less than 0.0125) and higher plasma insulin concentrations at similar time points (p less than 0.05), but stimulated plasma GIP concentrations were similar after 12 and 36 h fasts. These findings show that the increased insulinotrophic effect of oral glucose after 36 h fasting in non-obese subjects is not due to an associated augmentation of the glucose-induced GIP response.

Adolescent↗
PubMed1983

Intact neurotensin (NT) in human plasma: response to oral feeding.

Neurotensin-like immunoreactivity (NTLI) increases in human plasma postprandially. Intact neurotensin (NT) however, has been found to be a minor component of NTLI, the major components being the N-terminal fragments 1-11 and 1-8. Intact NT is the only known biologically-active form. A radioimmunoassay (RIA) has been developed which employs an antiserum unreactive to 1-11 or smaller N-terminal NT fragments. Using this RIA, intact NT response to a mixed meal has been assessed in 10 healthy humans. Intact NT levels were significantly elevated over basal 15 min after ingestion of the meal and remained so for the duration of the experiment (120 min). The suggestion that intact NT is a circulating hormone has been substantiated. Due to the rapidity of the rise in plasma NT after feeding it is proposed that the initial NT response is mediated by neural or hormonal means, rather than by direct luminal stimulation of the N cell-rich jejunoileum.

Eating↗
PubMed1983

The effect of age and sex on the response of enteropancreatic polypeptides to oral glucose.

Enteropancreatic polypeptide responses during a 50 g oral glucose tolerance test were studied in 10 young men, 10 young women, 10 elderly men and 10 elderly women. Elderly females had higher gastric inhibitory polypeptide (GIP) responses to oral glucose than elderly males. Elderly males and females had higher fasting and post-glucose human pancreatic polypeptide (HPP) levels than young males and females. N-Glucagon-like immunoreactivity (N-GLI) responses differed between the young and elderly. In the young, N-GLI levels fell after oral glucose but in the elderly they rose. Post-glucose C-glucagon-like immunoreactivity (C-GLI) responses were higher in elderly females than in young females. The significance of the higher plasma levels of GIP, N-GLI and C-GLI following oral glucose in elderly females compared to elderly males is unclear.

Adult↗
PubMed1983

Effects of eight weeks' continuous treatment with oral ranitidine and cimetidine on gastric acid secretion, pepsin secretion, and fasting serum gastrin.

Gastric acid secretion, pepsin secretion, and fasting serum gastrin levels were measured in 23 patients with duodenal ulcer disease, divided into three groups which received either cimetidine 800 mg daily, cimetidine 1600 mg daily, or ranitidine hydrochloride 300 mg daily for eight weeks. Pentagastrin tests were carried out at intervals both before and after treatment. Each dose of cimetidine reduced acid secretion to 42% of control one week after starting therapy. Ranitidine reduced acid secretion to 33% of the pretreatment value. Acid secretion remained suppressed to these levels throughout treatment with each drug. Acid secretion returned to pretreatment levels in all patients one week after treatment and remained normal until the end of the study. Both drugs reduced pepsin, which fell to 64% and 61% (p less than 0.01) after 800 mg and 1600 mg cimetidine respectively and to 65% (p less than 0.005) with ranitidine after one week's treatment. Pepsin secretion remained at this reduced level in both cimetidine groups till the end of treatment. Pepsin levels fell to 50% at two weeks of therapy with ranitidine but stabilised at this level till the end of therapy. Cimetidine withdrawal was followed by a return towards pretreatment levels of pepsin secretion; but secretion remained significantly depressed (p less than 0.05) to the end of the study period. In the ranitidine-treated patients pepsin output returned to normal after drug withdrawal. Fasting gastrin levels rose during treatment with both drugs but failed to reach significant levels. After withdrawal of treatment fasting serum gastrin levels returned to normal in all three groups of patients.

Anti-Ulcer Agents↗
PubMed1983

The prevalence of gastrinomas in recurrent peptic ulceration.

The prevalence of gastrinomas and the Zollinger-Ellison syndrome is unknown. In order to examine a high risk group of patients, basal and secretin-provoked plasma gastrin levels were determined in 50 consecutive patients, predominantly from the west of Scotland. All had endoscopically proven recurrent peptic ulceration following duodenal ulcer surgery. This resulted in three cases strongly suspected of having a gastrinoma. Further investigations including exploratory laparotomy were unable to demonstrate a gastrinoma in two, but the evidence suggested an occult tumour in one. In this remaining unoperated patient, the serum gastrin returned to normal. The reference range for both basal and secretin stimulated gastrin response and percentage change has been determined in normal control subjects (n = 10) and in primary ulcer patients (n = 20). It is concluded that in this study, gastrinomas had a less than 2 per cent prevalence in patients presenting with recurrent peptic ulceration. As the diagnosis of a gastrinoma changes the surgical approach, conducting screening tests still seems warranted.

Adolescent↗
PubMed1983

Radioimmunoassay for pancreatic polypeptide, and its age-related changes in concentration.

Pancreatic polypeptide (PP), a recently discovered pancreatic hormone, is potentially a marker for endocrine tumors. Consequently, we devised a radioimmunoassay for it, using antisera (raised in rabbits) to bovine PP, 125I-labeled bovine PP (purified by anion-exchange chromatography), and human PP standards. Concentrations circulating in fasting, normal subjects were measured. Statistical analysis of the results revealed a skewed distribution. An age-related increase was also observed. Evaluating PP concentrations in sera from 23 patients with endocrine tumors, we found increased values in a few cases of Zollinger-Ellison syndrome, medullary carcinoma of the thyroid, carcinoid syndrome, and one tumor producing vasoactive intestinal polypeptide (VIPoma). In contrast, values from five insulinomas and one glucagonoma were within the normal reference interval. Thus, an increased value for PP in a fasting individual may suggest the diagnosis of an endocrine tumor but is not a diagnostic prerequisite.

Adenoma, Islet Cell↗
PubMed1983

The diffuse endocrine system in cystic fibrosis.

The pathology, aetiology and clinical features of cystic fibrosis (CF) are briefly reviewed. The diffuse endocrine system (DES) may be involved in either a primary or secondary manner. Carbohydrate intolerance is common and the release of islet hormones is deficient, as is the release of the intestinal hormone gastric inhibitory polypeptide (GIP). The post-prandial responses of insulin and GIP can be improved by substituting an elemental meal, suggesting that malabsorption and local intestinal factors could be causative in the deficient responses. Vasoactive intestinal polypeptide-like immunoreactive (VIP-LI) cell numbers are increased in CF and an intimate association with mucous cells is noted suggesting a paracrine relationship. These findings could have implications in the diagnosis, management and aetiology of CF.

Atrophy↗