Effect of Vincristine on Motility and Histology of Gastrointestinal Tract of Albino Rats

Vincristine, an alkaloid of periwinkle plant (vinca) used in the treatment of various malignancies. The experimental group included 36 male wistar albino rats. The animals were divided into four groups of nine animals each. The animals received same dose of vincristine 1 mg/kg b.w. given intragastrically through a ne rubber catheter reaching lower third of oesophagus. Equal number of controls corresponding to each group was given vehicular uid by the same route. The animals of Group I, II, III and IV were used for the barium meal study after 1 hr, 5 hr, 12 hr and 24 hr respectively following the intragastric administration of the dose. The design of experiment was such that animal of Group I, II, III and IV were on fasting for 13 hr, 17 hr, 24 hr and 36 hr respectively before being used for the barium meal study. The observation on animals studied after 1 hr, 5 hr, 12 hr and 24 hr of intragastric dose suggest that the drug initiate slowing down of motility within 1 hr (control group 64.13±11.36cm and experimental group 62.02±4.90cm) and increase motility within ve hours of intragastric dose (control group 64.99±6.0 cm and experimental group 68.92±3.40cm). The observation also shows that between 12-24 hours, the motility of small intestine was decreased. This decrease of intestinal motility in experimental animals as compared to control group was signicant (p<0.01). The alkaloid reduces the rate of gastric emptying and slowed the transit of test substance through the small intestine. Address for Correspondence: Dr. Archna Associate Professor, Department of Physiology, Subharti Medical College, Meerut INTRODUCTION The vinca alkaloids are naturally occurring or semi synthetic nitrogenous bases extracted from the vinca rosea, a common owering herb known as periwinkle 1,2 plant. Vincristine is a chemotherapeutic agent derived from Vinca rosea (Linn), which has been widely employed against hematological malignancies 3,4 and solid tumors since the 1960. They are known to be neurotoxic and produce severe gastrointestinal toxicity including diarrhea, 5-8. constipation, and pain in abdomen and vomiting The toxicity of the alkaloids pertaining to the GIT indicates that the alkaloids affect GIT motility which is 9-12 reected in kinds of symptoms seen clinically . L o o k i n g a t t h e p h a r m a k o d y n a m i c s a n d pharmacokinetic of vinca alkaloids It becomes clear that the vinca alkaloids are rapidly excreted in large percentage of the dose through the biliary system 13,14 into the gut lumen. This suggests that the vinca alkaloids could reach the GIT tract tissue via the blood stream on administration I/V or topically on excretion 15 through the biliary system. The possibility is that Vinca Alkaloid could inuence gut motility while circulating in the circulation as has been shown earlier w h e n t h e a l k a l o i d s w e r e a d m i n i s t e r e d 16 intraperitoneally in the experimental animals. Thus the objective of the present study was to determine the effect of vincristine on gastrointestinal motility of albino rats. MATERIALS AND METHODS Animal The present study was conducted on 72 albino rats of wistar strain kept under standard laboratory conditions. Rats were caged with 4-5 rats per cage, in a well ventilated room at temperature ranging between 28oC to 32oC with normal day and light. They had free access to freshly prepared diet and water. Experimental Protocol The animals were divided in to 4 groups 18 each. Control group was given vehicular uid while experimental group was given vincristine (dose 1mg/kg b.w.) by intragastric route. The animals of either group were fasted for specied period ranging from 12-36 hrs before experimentation. The animals had free access to water during the period of fasting. Barium meal study Experimental Procedure Seventy two rats were divided into 4 groups (Group IJ. Anat. Sciences, 22(2): Dec. 2014, 18-21