E2-R - 17β-estradiol 60 days

• Implants designed to release daily doses of oestradiol to produce physiological plasma concentrations in rats and mice. (The normal values of oestradiol in these rodents are between 2.4 and 145.4 pg/ml.)
• Excellent correlation between the in vitro diffusion values and plasma concentrations (Fig. 1).

Fig 1: Correlation between in vitro and in vivo measurements in the rat.

• Extremely small inter-implant variations and constant hormone release.
• Doses chosen to promote hormone-dependent tumour cell growth in murine models.
• The amount of oestradiol released over 24 hours makes it possible to achieve plasma concentrations corresponding to the pre-ovulatory stage. These physiological conditions are sufficient to stimulate tumour growth whilst limiting the renal problems (crystals in the bladder) that are commonly seen with overly high oestradiol doses. (1).

Fig 2: Daily doses of hormone released by Belma's E2 implants (E2-M/60, blue lines) and matrix pellets (1.7mg or 0.7mg/60 days, red lines) over time. The plots correspond to the means ± SD (n=3). Note the high scatter of the measurements obtained with the matrix pellets.

• May also be used in research linked to reproduction and gynaecological problems, where they can replace the lower-dose matrix pellets quite advantageously.

Fig 3: Daily doses of hormone released by matrix pellets (0.1mg/60 days) and Belma's E2 implants (E2-M/60) over time. The plots correspond to the means ± SD (n = 3).

Bibliography :
Gérard C. et al. Accurate Control of 17β-Estradiol Long-Term Release Increases Reliability and Reproducibility of Preclinical Animal Studies. J Mammary Gland Biol Neoplasia. 2017 Mar;22(1):1-11.