Effects of cisplatin and taxol on inducible nitric oxide synthase, gastrin and somatostatin in gastrointestinal toxicity.

Cisplatin (9 mg/kg) or taxol (20 mg/kg) treatment of Wistar rats produced a sharp decrease in inducible nitric oxide synthase (iNOS) and gastrin in the pyloric region of the stomach, and an increase in iNOS and somatostatin in the pancreatic islets. Nitric oxide (NO) functions as a relaxation factor in the smooth muscle of the muscularis mucosa while gastrin plays an important role in the gastroprotection of the mucosa through NO. It is proposed that a decline of the iNOS and gastrin after cisplatin or taxol treatments is related to distention of the stomach, and possibly nausea and vomiting. Hyperglycemia and glucose intolerance after cisplatin treatment may be caused by increases of somatostatin and iNOS in the pancreatic islets. Combination therapy with cisplatin and taxol seems to ameliorate various toxicities due to these two individual drugs.