Induction of Cerebral Microhemorrhages in a Rat Model Using Lipopolysaccharide

Samenvatting

Source: Li, D., et al. Sub-acute Cerebral Microhemorrhages Induced by Lipopolysaccharide Injection in Rats. J. Vis. Exp. (2018).

This video demonstrates the process of inducing blood-brain barrier (BBB) disruption and cerebral microhemorrhages in a rat model using lipopolysaccharide (LPS). It highlights the sequence of immune responses that lead to increased BBB permeability and subsequent brain tissue damage.

Protocol

All procedures involving animal models have been reviewed by the local institutional animal care committee and the JoVE veterinary review board.

1. Materials

1. Preparation of LPS injection​
   1. Add 25 mL of distilled water to 25 mg of LPS powder derived from Salmonella typhimurium to a final concentration of 1 mg/mL. Store the injection in a sterile tube at 4 °C.
      CAUTION: LPS is toxic.

2. Animals

1. Administer LPS to male Sprague-Dawley (SD) rats, aged 10 weeks (average weight: 280 ± 20 g) by intraperitoneal injection.
   CAUTION: If rats are purchased from another organization, then the adaptive phase should not be less than 7 days.

3. LPS Injections

1. Inject LPS intraperitoneally into each rat at a dose of 1 mg/kg and return the rats to their home cage.
   NOTE: Anesthesia is not necessary.
2. Six hours later, inject the same dose of LPS injection into the rats.
3. Sixteen hours later inject the same dose of LPS into the rats.
   CAUTION: Injecting SD rats with LPS at a dose of 1 mg/kg may result in a 5% mortality rate. The mortality rate could further increase in younger or older rats or pregnant female rats.
4. Return the rats to their cages after LPS injection and provide ad libitum access to food and drink.
   NOTE: Rats will exhibit a distinct systemic inflammatory response, and thus the cages must remain clean throughout the experiment. Rats should be frequently (2x day) monitored for weight, general appearance, and attitude after the first LPS injection. If the rats start to exhibit a hunched posture, unwillingness to move, significant weight loss (>20%), or porphyrin staining, they should be humanely euthanized before the 7-day study endpoint.

Materialen

Lijst van materialen gebruikt in dit artikel

Naam	Bedrijf	Catalogusnummer	Opmerkingen
LPS	Sigma-Aldrich	L-2630	for inflammation induction
Phosphate buffer saline (PBS)	Solarbio	P1022	a kind of buffer solution commonly used in experiment