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Biomedical subjects

S N Madsen

Publications and source records attributed to S N Madsen.

At least 37 records · Page 2Linked to original sources

Cyclic AMP, adrenaline and noradrenaline in plasma during surgery.

Plasma concentrations of cyclic AMP, adrenaline and noradrenaline were measured in 6 patients undergoing hysterectomy from before induction of anaesthesia to 6 h after skin incision. Noradrenaline did not vary significantly during the observation period, whereas cyclic AMP and adrenaline increased after skin incision. A significant correlation was found between plasma concentrations of cyclic AMP and adrenaline (r = 0.84, P less than 0.01), suggesting that the latter is responsible for the increase in plasma cyclic AMP which is observed in relation to surgical procedures. Peak concentrations of cyclic AMP and adrenaline were seen in the early postoperative phase. This indicates that the most pronounced acute endocrine stress response to surgery of moderate severity occurs after termination of anaesthesia.

Adult↗

Influence of morphine anaesthesia on the endocrine-metabolic response to open-heart surgery.

Twelve patients scheduled for aortic valve replacement during extracorporal circulation were randomly allocated to either morphine anaesthesia or fluroxene anaesthesia. Morphine in a total dose of 4 mg/kg was administered before skin incision. At the start of extracorporal circulation all patients received 25 g glucose intravascularly. The endocrine-metabolic response to surgery, as expressed by changes in plasma ACTH, cortisol, insulin, growth hormone, cyclic adenosine-3',-5'-monophosphate (cyclic AMP), glucose, free fatty acids, blood b-hydroxybutyrate and cumulative nitrogen balance was measured before and during anaesthesia and surgery, and on the first five post-operative days. It was found that morphine anaesthesia blocked the increase in ACTH, cortisol, growth hormone, cyclic AMP, and glucose during surgery. However, after initiation of extracorporal circulation only ACTH, cortisol, and, to a lesser degree, the glucose and insulin response to glucose were lowered by morphine anaesthesia. From the first to the fifth days after operation no differences between the two groups could be demonstrated in any parameter. Cumulative nitrogen balance was similar in the two groups. It is concluded that morphine in large doses administered before skin incision inhibits the initial endocrine-metabolic response to open-heart surgery, but that the effect is short-lasting and without effect on overall postoperative protein catabolism.

Adolescent↗

Inhibition of plasma cyclic AMP, glucose and cortisol response to surgery by epidural analgesia.

Cyclic AMP, glucose and cortisol in plasma were measured in three groups of patients undergoing hysterectomy. The operations were performed under general anaesthesia, under general anaesthesia combined with epidural analgesia and under epidural analgesia alone. Surgery elicited a significant rise in plasma cyclic AMP, glucose and cortisol when performed under general anaesthesia alone. Epidural analgesia extending from T4-6 to S5 combined with general anaesthesia abolished the rise in cyclic AMP and reduced the increase in glucose and cortisol and epidural analgesia alone extending from T4 to S5 blocked the rise in glucose and cortisol as well as that in cyclic AMP. The results support the theory that afferent nerve impulses from the area of trauma are of major importance for the catabolic state induced by surgical procedures and indicate that anaesthetic management which includes blockade of afferent nerve impulses which includes blockade of afferent nerve impulses from the area of trauma can be reduce the catabolic response to surgery. These observations could be of value in the operative management of patients with diabetes mellitus and possibly in other groups by patients with a high surgical morbidity.

Adult↗

Effect of human leucocyte migration inhibitory factor (LIF) on 3', 5'-cyclic AMP levels of peripheral blood leucocytes.

The possible involvement of 3', 5'-cyclic AMP (cyclic AMP) in the mechanism of action of leucocyte migration inhbitory factory (LIF) was tested. LIF-treated human peripheral blood leucocytes were incubated at 37 degrees C for various times between 0 and 22 h. The concentrations of cyclic AMP in these cultures did not differ from those in controls. Furthermore, LIF did not affect the cellular release of cyclic AMP. Neither when testing purified neutrophils, which are the prime targets of LIF action, an effect of LIF was found. Cyclic AMP levels decreased with time of incubation, whether testing mononuclear cells (92 per cent lymphocytes), purified neutrophils (98 per cent), or buffy coat cells (72 per cent neutrophils; 22 per cent lymphocytes). However, a transient and as yet unexplained increase in the cyclic AMP levels of the latter mixed population of cells was manifested within 10 to 30 min of incubation.

Cells, Cultured↗

Thyroid function and plasma cyclic AMP response to intravenous glucagon.

The glucagon stimulated increase in plasma cyclic AMP has been studied in 17 healthy subjects, in 13 hyperthyroid and in 14 hypothyroid patients. Six hyperthyroid and 2 hypothyroid patients were re-investigated after at least 15 months of treatment. The results show: 1) The glucagon stimulated cyclic AMP response is significantly increased in hyperthyroid patients considered as a group, and is reduced in patients with hypothyroidism. 2) Three hyperthyroid and 4 hypothyroid patients showed a normal response to iv glucagon, indicating that the plasma cyclic AMP response to iv glucagon is not a sensitive test for the evaluation of peripheral thyroid states. This suggests that the effects of thyroid hormones in the liver does not necessarily follow the effects in other tissues. 3) Re-investigation of treated patients showed that the cyclic AMP response can be normalized by treatment, both in hyperthyroidism and hypothyroidism. However, in patients treated for hyperthyroidism a hyper-response to glucagon can continue after blood levels of thyroid hormones are reduced to normal. This suggests an inertia in the loss of the hyper-response to glucagon, once a hyperfunction has been induced. A similar inertia in the loss of glucagon sensitivity in hypothyroidism could explain the large number of normal tests in hypothyroid patients.

Adult↗

Cyclic AMP, glucose and cortisol in plasma during surgery.

Cyclic AMP, glucose and cortisol in plasma were measured before, during and after major surgery (hysterectomy, six patients) and minor surgery (tympanoplasty, 10 patients). During major surgery cyclic AMP as well as glucose and cortisol showed a pronounced increase. During minor surgery cyclic AMP, glucose and cortisol levels were significantly lower than in the group undergoing major surgery. It is concluded that the increase of plasma cyclic AMP during operative procedures is related to the severity of the trauma.

Adult↗

A simple competitive protein-binding assay for adenosine-3',5'-monophosphate in plasma and urine.

A modified competitive protein-binding assay for the measurement of adenosine-3',5'-monophosphate is described. The procedure allows measurement of adenosine-3',5'-monophosphate in unextracted plasma samples. The mean plasma values in 25 normal, fasting and ambulatory subjects were 22.7 +/- 4.7 pmol/ml (mean +/- SD) (range 13-31 pmol/ml. The mean urinary content was 3.2 +/- 1.0 mumol per g creatinine (mean +/- SD) (n=24).

Binding, Competitive↗

Urinary cyclic AMP. Relation to albumin-corrected serum calcium in healthy persons and patients with primary hyperparathyroidism.

In 21 healthy volunteers, mean excretion of cyclic adenosine 3',5' monophosphate (cAMP) in urine was 4.2 +/- 1.0 (S.D.) mumol cAMP/24 hours, 3.0 +/- 1.2 mumol/g creatinine and 3.8 +/- 1.2 mumol/24 hours/100 ml/min renal clearance of creatinine (CCr). An inverse correlation exists between the excretion of cAMP and serum calcium corrected for variations in serum albumin, most clearly demonstrated when cAMP is expressed as mumol/24 hours/100 ml/min of CCr (r=-0.630, p less than 0.01). In 21 patients with operatively verified hyperparathyroidism, the mean urinary excretion of cAMP/24 hours was 5.0 +/- 1.9 mumol uncorrected, 4.8 +/- 1.8 mumol/g creatinine and 6.6 +/- 2.1 mumol/100 ml/min of CCr. The latter two of these parameters differ significantly from the normal group (p less than 0.001), but conceal the fact that many patients with hyperparathyroidism excrete normal amounts of cAMP in the urine, independent of the mode of calculation. However, when cAMP is correlated to albumin-corrected serum calcium, this overlap between hyperparathyroidism and normality disappears completely. The results support the concept that cAMP excretion is influenced to a considerable degree by the biological activity of circulating parathyroid hormone. They also indicate that the simultaneous measurement of cAMP in urine and albumin-corrected calcium in serum is a useful aid in distinguishing hyperparathyroidism from the state of normality.

Adolescent↗