Splanchnic nerve stimulation in bursts at low (5 Hz) and high (50 Hz) frequency (30 V, 1 msec; train duration 1 sec; train rate 0.5/second) was employed in 10 cats under halothane anesthesia, during 10-minute periods, while blood samples were concurrently collected from the adrenal vein and femoral artery for the measurement of norepinephrine (NE), epinephrine (EPI), dopamine (DA), Met-enkephalin (ME), neuropeptide Y (NPY), peptide YY (PYY) and neurotensin (NT). In Group I (n = 5), splanchnic nerve stimulation was initially applied at 5 Hz followed after 20 min by a 50 Hz stimulus, while in Group II (n = 5) the stimulation sequence was reversed. Adrenal vein and femoral artery plasma levels of catecholamines and neuropeptides were not significantly affected by the stimulation sequence, while a significant decrease in blood pressure response was observed in Group II during the 5 Hz stimulation as compared to Group I, indicating desensitization. Splanchnic nerve stimulation at 5 Hz caused a preferential increase in adrenal vein NE (9-fold) versus EPI (7-fold) levels as compared to baseline, while 50 Hz stimulation led to further comparable increases in NE (5-fold) and EPI (6-fold) levels. Significant increases in adrenal vein DA and neuropeptide levels were only observed during 50 Hz stimulation, with DA showing a 5-fold, ME a 2.6-fold and NPY a 3-fold increase as compared to 5 Hz stimulation, and NT a 3.6-fold increase as compared to baseline. Present findings indicate different dynamics in the movement of catecholamines and neuropeptides from the adrenal.

Adrenal Glands↗

PubMedDate not supplied

High energy phosphates and catecholamine stores after prolonged ex vivo heart preservation.

Previously, we have demonstrated that hearts preserved ex vivo for 12 hours maintain normal hemodynamic performance after orthotopic transplantation. To complete our studies of these preserved hearts, we evaluated myocardial metabolism by determining high energy phosphate levels and catecholamine concentrations in 22 canine hearts. Group I was the control group in which six hearts were given cold cardioplegic solution; full thickness biopsies were taken from the myocardium in two areas of the right and left ventricles and septum; and adenosine triphosphate, adenosine diphosphate, adenosine monophosphate, creatine phosphate, and catecholamines were determined. Group II, in which the hearts were preserved 12 hours, had eight hearts that were stopped with cold cardioplegic solution, excised, and then preserved in an ex vivo state with a 32 degrees C modified blood perfusate. After a 12-hour perfusion period, the hearts were stopped and biopsies taken. Group III involved cold ischemia and had six hearts that were stopped with cardioplegic solution, excised, opened, flushed, and stored for 2.5 hours at 2 degrees to 4 degrees C. Biopsies were obtained as in groups I and II. Adenosine triphosphate levels were slightly reduced in the 12 hour preserved heart when compared with the control group and the heart in the cold ischemia group preserved for 2.5 hours (p less than 0.01). Creatine phosphate levels were significantly elevated after 12 hour preservation when compared with groups I and III (p less than 0.01). Hearts preserved by cold ischemia also had a reduction (p = 0.03) of creatine phosphate when compared with the control group.(ABSTRACT TRUNCATED AT 250 WORDS)

Adenine Nucleotides↗

PubMedDate not supplied

The carcinoid syndrome--a role for hemodialysis.

Explore the source record for details and available documents.

Humans↗