The effect of selective sympathetic denervation on pancreatic exocrine secretion

Catecholamines and 5-hydroxytryptamine in tissues of the rabbit exocrine pancreas

OBJECTIVES

Norepinephrine (NE), dopamine (DA), epinephrine (Epi), and 5-hydroxytryptamine (5-HT) all modulate pancreatic exocrine secretion, yet their concentrations in specific tissues of the exocrine pancreas are unknown.

METHODS

Concentrations of catecholamines and 5-HT in rabbit pancreatic ganglia, acini, ducts and ampullae, and arteries and veins were measured using HPLC.

RESULTS

Concentrations of NE in ganglia from the head/neck region were significantly higher than those from the body (1620 +/- 220 vs. 778 +/- 179 pmol/mg protein). Acini contained little NE, DA, or 5-HT (9 +/- 2, 0.9 +/- 0.2, 13 +/- 5 pmol/mg protein). Ducts and ampullae contained NE (314 +/- 74 and 156 +/- 24 pmol/mg protein), DA (43 +/- 14 and 13 +/- 4 pmol/mg protein), Epi (63 +/- 29 and 39 +/- 6 pmol/mg protein), and 5-HT (696 +/- 151 and 3563 +/- 288 pmol/mg protein). Arteries and veins contained the highest concentrations of NE (1962 +/- 463 and 736 +/- 80 pmol/mg protein, respectively).

CONCLUSIONS

Pancreatic ganglia and blood vessels, rather than acini, are the main sites of noradrenergic sympathetic innervation of the rabbit exocrine pancreas. These nerves preferentially target ganglionic transmission in the head/neck versus the body. Serotonergic nerves provide little or no innervation of rabbit pancreatic ganglia or acini.

Differential roles of endogenous nitric oxide on neural regulation of basal exocrine pancreatic secretion in intact and denervated pancreas

BACKGROUND

Autonomic nerves and humoral factors regulate pancreatic secretion. Nerves containing nitric oxide (NO) synthase (NOS) are in close proximity and located within cholinergic, adrenergic and sensory nerve bundles. Yet, the interactive mechanisms between various nerve populations remain elusive.

AIMS

To evaluate the role of endogenous NO in basal exocrine pancreatic secretion in the extrinsically denervated rat pancreas.

METHODS

Male Sprague-Dawley rats were assigned to 2 groups of 11 animals. The first group of sham-operated animals served as controls. In the second group extrinsic pancreatic innervation was surgically interrupted. One week later, after selective catheterization of the celiac axis and the bile-pancreatic duct, the animals received intra-arterial infusions of NG-nitro-L-arginine (L-NNA; 0.48 mg/kg b.w./h) followed by intra-arterial infusions of L-arginine (110 mg/kg b.w./h). Total protein and amylase were measured in bile-pancreatic secretions collected at 15-min intervals.

RESULTS

In controls, total protein and amylase output showed a biphasic secretion pattern with an increase during L-NNA infusion followed by a decrease when the infusion ceased and further augmentation 1 h later. In denervated animals, L-NNA caused a sustained decrease in pancreatic secretion followed by an increase 1 h later. Infusion of L-arginine at the time of maximum decrease slowed the second phase of protein and amylase output in sham-operated rats, but accentuated the onset of secretion in denervated animals.

CONCLUSION

Inhibition of endogenous NO release was shown to increase baseline secretion in the intact pancreas. Superposition of extrinsic denervation on neural NOS-blockade decreased basal exocrine secretion, indicating that intra-pancreatic NO release is regulated by extra-pancreatic nerves.

Bilateral thoracoscopic splanchnicectomy: effects on pancreatic pain and function

OBJECTIVE

To evaluate prospectively the effect of bilateral thoracoscopic splanchnicectomy on pancreatic pain and function.

SUMMARY BACKGROUND DATA

Severe pain is often the dominant symptom in pancreatic disease, despite a wide variety of methods used for symptom relief. Refinement of thoracoscopic technique has led to the introduction of thoracoscopic splanchnicectomy in the treatment of pancreatic pain.

METHODS

Forty-four patients, 23 with pancreatic cancer and 21 with chronic pancreatitis, were included in the study and underwent bilateral thoracoscopic splanchnicectomy. Effects on pain (visual analogue scale) and pancreatic function (standard secretin test, basal serum glucose, plasma insulin, and C-peptide) were measured.

RESULTS

Four patients (9%) required thoracotomy because of bleeding. There were no procedure-related deaths. The mean duration of follow-up was 3 months for cancer and 43 months for pancreatitis. Pain relief was evident in the first postoperative week and was sustained during follow-up, the average pain score being reduced by 50%. All patients showed a decrease in consumption of analgesics. Neither endocrine nor exocrine function was adversely affected by the procedure.

CONCLUSIONS

Bilateral thoracoscopic splanchnicectomy is beneficial in the treatment of pancreatic pain and is not associated with deterioration of pancreatic function.