Dose-dependent effect of continuous subcutaneous verapamil infusion on experimental acute pancreatitis in mice

Calcium antagonists may limit experimental tissue injury by membrane stabilization. We studied the effects of verapamil on pancreatic ultrastructure and zymogen extraction during diet-induced acute pancreatitis. Acute pancreatitis was induced in female Swiss-Webster mice by feeding a choline- and methionine-deficient diet (CD) supplemented with 1% ethionine (CDE). Varying doses of verapamil in normal saline were infused continuously at a rate of 0.5 microliter/hr for 96 hr through subcutaneously implanted osmotic pumps. The pancreata were examined blindly by light microscopy and by electron microscopy. Zymogen extracted from pancreatic tissue was measured and expressed per gram of protein. Mean histological scores, calculated according to a formula that incorporates the extent of necrosis, inflammation, acidophilia, and edema, were 14.1 +/- 4, 10.3 +/- 2, 9.9 +/- 4, 5.9 +/- 7, 12.5 +/- 4, and 12.7 +/- 4 for CDE-fed animals receiving 0, 0.14, 0.28, 0.56, 0.84, and 1.12 microM verapamil daily, respectively. Animals fed normal diet or CD had scores of 0 +/- 0. Histological scores were significantly lower in animals treated with 0.56 microns verapamil compared to animals who received no verapamil (p < 0.05) and was associated with reduced dissolution of the zymogen granule membrane on EM. Mean extracted trypsinogen and chymotrypsinogen content were reduced in the CD- and CDE-fed mice. The reduction in mean trypsinogen content reached statistical significance in CDE-fed mice treated with verapamil 0.56 microM daily. Mean chymotrypsinogen content was also significantly reduced CD-mice and in mice treated with 0.56 microns and 0.84 microM of verapamil daily. Increasing doses of verapamil protect against diet-induced pancreatitis in mice.(ABSTRACT TRUNCATED AT 250 WORDS)