Digestive

Question 1

What species can see death secondary to gavage-related reflux? What factors are associated with this condition?

Answer 1

Rats
High volumes to fed animals, irritant or viscous compounds, those that delay gastric emptying, high concentrations of high-dose formulations, and clinical condition of animal (CNS depression)

Question 2

What species have a palatal ostium?

Answer 2

GP, chinchillas, and other hystricomorphs

Question 3

What structure do pigs possess that may impact gastric or endotracheal intubation?

Answer 3

Pharyngeal diverticulum

Question 4

Tooth removal should only be attempted after what structures have been severed?

Answer 4

Periodontal ligaments

Question 5

How can complete biliary retention be accomplished?

Answer 5

With retention and obstructive jaundice via ligation of common bile duct. Without obstruction be implanting a catheter between the common bile duct and venous return.

Question 6

What needs to occur during bile collection? How is this commonly acheived?

Answer 6

Maintenance of the enterohepatic recirculation.
‘U’-shaped cannula with one catheter toward the liver in the bile duct and a second toward the duodenum but short of the sphincter of Oddi.
T-shaped catheter also used in dogs.

Question 7

What is the minimum volume of liver needed for rodent survival?

Answer 7

5-10%

Question 8

Models of pancreatic endocrine function largely involve study of what disease?

Answer 8

Type I diabetes mellitus

Question 9

What models spontaneously develop type I DM?

Answer 9

NOD and BioBreeding rat

Question 10

What chemical methods induce type I DM?

Answer 10

Alloxan or streptozoticin (STZ).

Question 11

How does STZ induce type I DM?

Answer 11

Specific B-cell toxicity based on its use of the glucose transport protein GLUT2, which exists in higher concentrations in B cells.

Question 12

Via what route and frequency can STZ be used to induce diabetes?

Answer 12

IV or IP, with IV route being 90% that of IP.
Multiple low doses can yield more stable and predictable diabetic state than single injection.

Question 13

Chemical ablation for type I DM is effective in what species? Not effective in what species?

Answer 13

Effective: Mice, rats, rabbits, dogs, pigs, and NHPs
Cats are resistant to alloxan and STX, need surgical removal +/- chemical techniques

Question 14

In rats and swine, coadministration of which agents can create a stable state of moderate post-prandial or fasting hyperglycemia?

Answer 14

Nicotinamide and STZ

Question 15

Total pancreatectomy is well described in what species? More difficult in what species? Why?

Answer 15

Well-described in dogs and swine, more difficult in lab rodents due to diffuse nature of pancreas.

Question 16

Is heterotopic or orthotopic transplantation of the pancreas more common?

Answer 16

Heterotopic

Question 17

Describe Thiry fistulas and Thiry-Vella loop fistulas. Why are they needed?

Answer 17

Thiry: One end exteriorized
Thiry-Vella: Both ends exteriorized
Research may require segments of the digestive tract that have no continuity with the fecal stream.

Question 18

What is critical regarding intestinal anastomoses?

Answer 18

Method of anastomoses. Preferred technique is usually single, interrupted, approximating sutures that minimizes tissue trauma and narrowing. Particularly true in rat and GP where tissue is very friable.

Question 19

Describe the RITARD technique?

Answer 19

Reversible intestinal tie-adult rabbit diarrhea model. Temp occlusion of a section of bowel for bacterial colonization studies. Uses sterile umbilical tape tied so that ligatures can be loosened and removed by gentle traction on the ends that are exteriorized through the incision site. All models have temp small intestinal ligation and permanent cecal ligation at a site just distal to the sacculus rotundus. Occlusion of cecum prevents absorption of fluids secreted from small intestine.