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Biomedical subjects

J N Lucke

Publications and source records attributed to J N Lucke.

At least 19 recordsLinked to original sources
PubMed1983

Porcine malignant hyperthermia. IX: Changes in the concentrations of intramuscular high-energy phosphates, glycogen and glycolytic intermediates.

A technique of obtaining muscle biopsies with a liquid nitrogen cryoprobe was used to study intramuscular metabolites in MH-susceptible and unsusceptible pigs. There was no significant difference in muscle metabolite values obtained from susceptible and unsusceptible pigs in the resting state. During MH the changes in metabolites were a result of rapid glycogenolysis and no abnormality of glycolytic control was observed.

Adenosine Diphosphate↗
PubMed1983

Toxicity testing of atracurium.

The toxicity of atracurium has been investigated in subacute tests in rat, dog and monkey, in a fetal toxicity test in the rabbit and in a paranatal study in the cat. No specific adverse effects were found despite administration of supraparalysing doses. It appeared not to cross the placenta at term and the neonatal kitten seemed resistant to its neuromuscular blocking action. In the dog, cat and pig, in which physiological monitoring was undertaken, i.v. injection of three to four times the paralysing dose had little or no effect on arterial pressure or heart rate. The solution did not cause local irritation. Atracurium was not mutagenic in the Ames test.

Animals↗
PubMed1982

Effect of dantrolene on leg metabolism in porcine malignant hyperthermia.

The effect of the intravenous administration of dantrolene 3.5 mg/kg body weight on leg metabolism during porcine malignant hyperthermia (MH) was investigated in six Pietrain pigs. Arterial pH improved only slowly after dantrolene and was associated with the continuing efflux of lactate from the leg. Oxygen uptake by the leg had returned to control values 30 minutes after dantrolene. Glucose production by the leg was observed during malignant hyperthermia but this was rapidly abolished by dantrolene. It is concluded that the most useful indices for assessing the adequacy of the treatment of MH are those which reflect changes in oxidative muscle metabolism.

Animals↗
PubMed1982

Changes in circulating gut hormones in the horse during long distance exercise.

Venous blood samples were collected before and immediately after an 80 km ride and a 42 km race. They were analysed for blood glucose and lactate, and for plasma non-esterified fatty acids, insulin, pancreatic glucagon, pancreatic polypeptide, gastrin, gastric inhibitory peptide, somatostatin and vasoactive intestinal polypeptide concentrations. The 80 km ride was associated with marked hypoglycaemia and a slight lactic acidaemia together with an increase in plasma glucagon, somatostatin, pancreatic polypeptide and vasoactive intestinal polypeptide values. The 42 km race produced hyperglycaemia and marked lactic acidaemia together with an increase in plasma glucagon, somatostatin and vasoactive intestinal polypeptide. The increase in these peptides is not related to alterations in blood glucose or the relative contributions of aerobic and anaerobic muscle metabolism. It is suggested that the changes in circulating gut peptides are part of the endocrine response to exercise and the possible physiological role of these changes is discussed.

Animals↗
PubMed1980

A biochemical study of the Arab Horse Society's marathon race.

Blood samples were taken before and after a cross country race over the marathon distance of 42 km. There was a rise in blood glucose and plasma free fatty acids and glycerol associated with a rise in plasma cortisol and glucagon but the fall in insulin was not significant (P > 0.05). Plasma potassium and albumin concentrations increased, calcium decreased and there was no change in sodium or bicarbonate concentrations. There was an increase in plasma urea, creatinine, uric acid, bilirubin and isocitrate dehydrogenase but no change in alkaline phosphatase. There was a rise in plasma creatine kinase. These results of a competitive race are compared with those of the 80 km non-competitive Golden Horseshoe Ride.

Animals↗
PubMed1980

Porcine malignant hyperthermia. VII: Hepatic metabolism.

Hepatic metabolism during porcine malignant hyperthermia (MH) was investigated in seven Pietrain pigs. The estimated hepatic blood flow decreased during MH, but an increase in oxygen extraction enabled the splanchnic oxygen uptake to be maintained. There was a large release of glucose and potassium from the liver in MH which made an important contribution to the hyperglycaemia and hyperkalaemia. Measurement of hepatic uptake of the precursors of gluconeogenesis, lactate, glycerol and alanine, showed that glucose efflux from liver was derived mainly from glycogenolysis. Lactate uptake by the liver increased during MH, and there was no evidence of hepatic lactate production during the profound acidosis as suggested by in vitro studies with the isolated liver. There was no evidence of major abnormality of hepatic function during porcine MH.

Animals↗