Residual Strain Experiment in Mice

Prepare:

• Make hypothermic arrest solution 30 mM K+
• Camera, lens, shutter release, film loaded, extra film
• Surgical tray, instruments, glassware
• Anesthetic cocktail
• Floodlights, camera ready, data back on time
• Camera settings: Auto, F11, use 'spot' then 'highlight' for each picture ?
• Razor blade, cutting board, pins, clear container
• Paper, pencil for notes
• Tweezers
• Stainless steel microspheres, scalpel
 

Surgery:

• Anesthetize animal IP with Cocktail:
   5mg/kg Xylazine; 100mg/kg Ketamine; 2.5 mg/kg Morphine
• Body weight
• Shave
• Endotracheal tube, ventilate
• Open chest, expose heart and aorta
• Clamp aorta, arrest (30 gauge needle, ~0.2 ml), excise heart, rinse in saline
 

Data:

• Pin apex
• 2 equatorial slices, dry, sprinkle on beads
• Rinse excess beads in separate bath
• Submerse and photograph no-load state
• Pull from fluid and make radial cut
• Submerse again and photograph stress-free state
• Pictures for 10-15 minutes; record # and time of pictures
• Save tissue for hydroxyproline (freeze)

Arrest solution:
To make 100 ml hypothermic cardioplegic arrest solution (30 mM K+)use:
NaCl 0.40 g
KCl 0.22 g
Glucose 0.20 g
NaHCO3 0.10 g
Nifedipine 0.00002 g
BDM 0.30 g
1.0 ml 1000 Unit Heparin
100 ml distilled water

Nifedipine: Dissolve 10mg in Ethyl alcohol, fill to 50 ml with saline, use 0.1 ml per 0.1 liter cardioplegic solution