How should glucose be given to a rat? - briefly
Administer a sterile, isotonic glucose solution by intraperitoneal injection at approximately 2 g kg⁻¹ body weight, using a 0.1–0.2 mL volume per 100 g rat. Restrain the animal gently, disinfect the injection site, and deliver the dose with a fine‑gauge needle.
How should glucose be given to a rat? - in detail
Glucose administration to laboratory rats requires a sterile, isotonic solution prepared at a defined concentration, typically 20 % (w/v) D‑glucose dissolved in physiological saline. The solution should be filtered through a 0.22 µm membrane and stored at 4 °C if not used immediately; warm to room temperature before injection.
The common routes are:
- Intraperitoneal (IP) injection: rapid absorption, suitable for acute studies.
- Intravenous (IV) injection via tail vein: precise control of plasma levels, requires catheterization skill.
- Oral gavage: mimics dietary intake, slower rise in blood glucose.
- Subcutaneous (SC) injection: slower release, useful for prolonged exposure.
Dosage is calculated on a per‑kilogram basis. Standard protocols employ 1–2 g kg⁻¹ for IP or SC routes, delivering 0.5–1 mL per 100 g body weight. For IV administration, 0.2–0.5 g kg⁻¹ in a volume not exceeding 0.2 mL per 100 g is typical. Adjustments depend on experimental goals and baseline glucose levels.
Administration technique:
- Restrain the rat gently using a rodent restrainer or manual grip to minimize stress.
- Disinfect the injection site with 70 % ethanol.
- Use a 27–30 G needle for IP or SC injections; for IV, a 30 G needle attached to a 1 mL syringe.
- Insert the needle at a shallow angle (IP) or directly into the tail vein (IV), ensuring correct placement by aspirating a small amount of fluid before delivery.
- Inject the calculated volume slowly to avoid tissue damage or reflux.
After delivery, monitor the animal for at least 30 minutes. Measure blood glucose at baseline and at regular intervals (e.g., 5, 15, 30 minutes) using a calibrated glucometer or plasma assay. Observe for signs of hypoglycemia or hyperglycemia, such as lethargy, tremors, or seizures, and be prepared to intervene with dextrose rescue if necessary.