Establishment of a Simple and Effective Rat Model for Intraoperative Parathyroid Gland Imaging

Summary

To date, the development of parathyroid gland (PG) identification methods is limited by the lack of animal models in preclinical research. Here, we establish a simple and effective rat model for intraoperative PG imaging and evaluate its effectiveness by using iron oxide nanoparticles as a novel PG contrast agent.

Abstract

Parathyroid gland (PG) identification is a critical unmet need in thyroidectomy. The identification of the PG is challenging in thyroid surgery as it is similar in color to the thyroid gland. The lack of effective animal models in preclinical research is a severe limitation for the development of PG identification techniques. This protocol allows for the establishment of a simple and effective rat model for PG identification. In this model, black iron oxide nanoparticles (IONPs) are injected locally in the thyroid gland and rapidly diffuse within the thyroid gland but not the PG. A negatively stained PG and a positively stained thyroid gland can be easily identified by the naked eye without requiring external microscopes. The position of the PG can be identified by increasing the color contrast between the thyroid gland and the PG, based on the color of the black IONPs. This rat model is low-cost and convenient for PG identification, and the IONPs are a novel PG contrast agent.

Introduction

Parathyroid gland (PG) is small, oval-shaped endocrine glands located in the neck of humans and other vertebrates, which produce and secrete parathyroid hormones to regulate and balance calcium and phosphorus levels in the blood and in bones¹. Humans usually have two pairs of PG located behind the thyroid gland lobes in variable locations; the size of human PG typically measures 6 mm x 4 mm x 2 mm, with a weight of approximately 35-40 mg². Removal or damage of the PG causes hypoparathyroidism (HP), an endocrine disorder characterized by hypocalcemia and low or undetectable levels of parathyroid hormon....

Protocol

All animal studies have been approved by the Institutional Animal Care and Use Committee (IACUC) of the Institute of Basic Medicine and Cancer, Chinese Academy of Sciences. This is a non-survival surgery.

1. Animal

1. Use a 6-8-week-old female SD rat, weighing 250 g, for intraoperative PG imaging.

2. Anesthesia

1. Turn on the anesthesia machine.
2. Before beginning, ensure the isoflurane level is full in the anesthesia vaporizer. Then, turn on the oxygen and set the flow rate to 0.4-0.8 L/min. Induce anesthesia with 3-5% isoflurane....

Discussion

We demonstrate an IONPs-guided negative imaging technique of rat PG using black IONPs, which were injected locally in the center of the thyroid gland and diffused within the thyroid gland but not the PG. It enables clear identification of the PG with naked eyes without the aid of any microscope. Although transgenic mice with green fluorescent protein selectively expressed in the PG have been reported¹³, the model described in this paper is more straightforward to perform. It only ta.......

Materials

Name	Company	Catalog Number	Comments
alcohol	Li feng	9400820067
anesthesia machine	RWD Company	R520IE	Machine number
blade	Daopian	TB-JZ-10#
cylindrical pillow			made by ourselves
depilatory cream	Nair	TMG-001
electronic scale	Hong xingda	CN-HXD2
eosin	Thermo Fisher (Waltham, USA).	C0105S-2
erythromycin	Shuang ji (Beijing, China)	200409
gauze	Fulanns	YY0331-2006
heating pad	Johon (ShenZhen,China)	JH-36-2006
hematoxylin	Thermo Fisher (Waltham, USA).	C0105S-1
insulin injection needle	Jiangyin NanquanMacromolecule	20170702
iodophor cotton ball	HOYON	19-6007
iron oxide nanoparticle solution	Zhongke Leiming Technology (Beijing, China)	Mag9110-05
isoflurane	Sigma Aldrich (St Louis USA).	21112801
needle holder	Meijun	MH0587
operation table	BioJane	BJ-P-M
paraformaldehyde solution	Biosharp	21269333
rubber	G-CLONE	XT41050
scanning machine	Olympus	Slideview VS200
surgical forceps	Suping	SPHC-0676
surgical knife handle	Aladdin	S3052-06-1EA
surgical retractor	TOCYTO	18-4010
surgical scissors	Suping	SPHC-0795
surgical towel	Along technology	YCKJ-RJ-036205
suture	Ethicon	SA84G
suture with needle	Jinhuan (Shanghai,China)	F301
vascular forceps	Along technology	YCKJ-RJ-016218
Water Bath-Slide Drier	Hua su (Jinhua, China)	HS-1145