How much prednisolone should be injected into a rat? - briefly
A commonly used dose for rats is 1–5 mg of prednisolone per kilogram of body weight, administered subcutaneously or intraperitoneally, with the exact amount adjusted for the specific experimental protocol. Always confirm the dosage with the relevant institutional animal care guidelines and pharmacological references.
How much prednisolone should be injected into a rat? - in detail
Prednisolone dosing in laboratory rats depends on the experimental goal, route of administration, and the animal’s body mass. The most commonly reported regimens use a weight‑based calculation expressed in milligrams per kilogram (mg kg⁻¹).
Typical dosage ranges
- Anti‑inflammatory or immunosuppressive studies: 1–5 mg kg⁻¹ per day.
- Acute glucocorticoid challenge: 10–20 mg kg⁻¹ as a single injection.
Route considerations
- Intraperitoneal (IP) injection: most frequent; solution should be sterile, isotonic, and prepared in a vehicle such as sterile saline or phosphate‑buffered saline.
- Subcutaneous (SC) injection: suitable for prolonged release; volume limited to ≤0.2 mL per 100 g body weight to avoid tissue irritation.
Preparation and volume
- Determine the rat’s weight (e.g., 250 g).
- Select the target dose (e.g., 2 mg kg⁻¹).
- Calculate required amount: 0.25 kg × 2 mg kg⁻¹ = 0.5 mg prednisolone.
- Dissolve prednisolone in a suitable solvent (e.g., 0.9 % NaCl) to achieve a concentration that allows injection of ≤0.2 mL. For a 0.5 mg dose, a 2.5 mg mL⁻¹ solution yields a 0.2 mL injection volume.
Safety notes
- Verify sterility of the solution; filter through a 0.22 µm membrane if prepared ex vivo.
- Observe animals for signs of distress, hyperglycemia, or weight loss, especially at doses >10 mg kg⁻¹.
- Record injection site and time precisely for reproducibility.
Literature benchmarks
- Studies employing 1–5 mg kg⁻¹ IP prednisolone report consistent suppression of inflammatory markers without severe adverse effects.
- Doses of 10–20 mg kg⁻¹ are used to model acute glucocorticoid excess; mortality increases above 25 mg kg⁻¹.
Selecting an appropriate dose requires aligning the experimental hypothesis with these established ranges, adjusting for animal weight, and ensuring injection volume remains within tolerated limits.