Evaluation of solid-phase labels for gastric emptying studies in cats

Area of Science:

• Veterinary medicine
• Nuclear medicine
• Gastroenterology

Background:

• Accurate gastric emptying studies are crucial for evaluating the impact of diseases, drugs, surgical procedures, and stress in experimental animals.
• Developing reliable radiolabeled diets is essential for these studies, particularly in feline models.

Purpose of the Study:

• To evaluate the in vitro and in vivo stability of various radiolabels in commercially available cat foods.
• To determine the most suitable radiolabel for solid-phase gastric emptying studies in cats.

Main Methods:

• Dry and canned cat foods were labeled with different technetium-99m (99mTc) radiolabels, including pertechnetate, sulfur colloid, disofenin, and Dowex resin beads.
• In vitro stability was assessed by digesting labeled foods in various solutions (water, gastric juice, intestinal juice).
• In vivo testing was conducted by feeding selected radiolabeled diets to cats.

Main Results:

• 99mTc-Dowex beads showed high in vitro labeling efficiency but poor in vivo stability.
• Technetium-99m-disofenin demonstrated high in vitro solid-phase retention in both dry (92.5-89.5%) and canned (86-94.9%) cat foods across different digestive conditions.
• 99mTc-disofenin exhibited acceptable stability for in vivo studies.

Conclusions:

• Technetium-99m-disofenin is a suitable and stable radiolabel for solid-phase gastric emptying studies.
• This finding supports the use of commercially available cat foods for such research, enhancing experimental design and reliability.