Long-term regression of experimental endometriosis in a rat model treated with local application of levonorgestrel-loaded biodegradable microspheres

Peng Yuan, B. Chen, Biliang Chen, Yanhong Huang, Yuxin Huang, Xiaoyan Xin
Human Reproduction · 2012 · vol. 27(7) , pp. 2089–2095 · doi:10.1093/humrep/des142 · PMID:22563024 · W2098245890
article OA: closed CC0 ⤵ 4 in-corpus citations
View on OpenAlex View on PubMed View at publisher
⚙ AI-generated summary by claude@2026-06, 2026-06-08 ⓘ

Local application of levonorgestrel-loaded microspheres induced long-term regression of endometriotic cysts in rats for one year, comparable to GnRH agonist treatment.

One-sentence paraphrase of the abstract; not a substitute for reading it. No clinical advice. How this works

Abstract

BACKGROUND: A previous study demonstrated that local application of levonorgestrel-loaded polylactic acid microspheres (LNG microspheres) resulted in significant regression of endometriotic cysts in a rabbit model for 6 months without disturbing the metabolic parameters or ovarian function. In order to investigate the feasibility of local application of LNG microspheres as a long-term maintenance treatment for endometriosis, the suppressive effect of a single intra-cystic injection of LNG microspheres was studied for 1 year in a rat model. METHODS AND RESULTS: Twenty four rats with experimental endometriotic cysts were randomized to be treated with a single intra-cystic injection of LNG microspheres (n = 8); 6-month GnRH agonist (GnRHa, n = 8) or control (n = 8). Intra-cystic injection of LNG microspheres and GnRHa treatment caused comparable regression and atrophy in endometriotic cysts in the first 6 months. Compared with the control, the wet weight of the endometriotic cysts was significantly lower in both groups at Month 6 but by Month 12 only remained low in the LNG microspheres group (P < 0.01). The immunostaining of estrogen receptors (ERs) in both the epithelium and stroma and progesterone receptors (PRs) in the stroma was significantly weakened in the LNG microspheres group at Month 6 and was not fully restored at Month 12 (P < 0.01). Metabolic parameters and estrous cycle were not disturbed by local application of LNG microspheres. CONCLUSIONS: In a rat endometriosis model, the suppressive effect of a single intra-cystic injection of LNG microspheres was comparable to that of GnRHa, and was maintained for 1 year. The down-regulation of ERs and PRs might serve as possible mechanism of long-term effectiveness.

My notes (saved in your browser only)

Condition tags

mesh:D004715endometriosis

MeSH descriptors

Endometriosis Levonorgestrel Microspheres Absorbable Implants Animals Biocompatible Materials Biocompatible Materials Body Weight Disease Models, Animal Endometriosis Female Humans Levonorgestrel Random Allocation Rats Rats, Sprague-Dawley Receptors, Estrogen Receptors, Estrogen Treatment Outcome

Citation neighborhood

Papers in the corpus that this work cites (lower rings, blue) and that cite this one (upper rings, green). Dot size scales with the paper's in-corpus citation count — bigger dot = more influential within the endo/adeno field. Click a dot to open that paper. [ expand to 2 hops ] — adds papers reached through this work's immediate citers/citees. Heavier; up to 60 extra dots.

References (20)

Cited by (4)

Source provenance

europepmc
last seen: 2026-06-04T01:30:01.192114+00:00
openalex
last seen: 2026-06-04T00:00:01.174412+00:00
pubmed
last seen: 2026-05-13T22:16:17.081435+00:00
License: CC0 · commercial use OK