Dynamic Continuous Blood Extraction from Rat Heart via Noninvasive Microdialysis Technique

Summary

The present protocol describes a simple and efficient method for the real-time and dynamic collection of rat heart blood using the microdialysis technique.

Abstract

Dynamic analysis of blood components is of great importance in understanding cardiovascular diseases and their related diseases, such as myocardial infarction, arrhythmia, atherosclerosis, cardiogenic pulmonary edema, pulmonary embolism, and cerebral embolism. At the same time, it is urgent to break through the continuous heart blood sampling technique in live rats to evaluate the effectiveness of distinctive ethnic medicine therapy. In this study, a blood microdialysis probe was implanted in the right jugular vein of rats in a precise and noninvasive surgical procedure. Cardiac blood samples were then collected at a rate of 2.87 nL/min to 2.98 mL/min by connecting to an online microdialysis sample collection system. Even more momentously, the acquired blood samples can temporarily be stored in microdialysis containers at 4 °C. The microdialysis-based online continuous blood collection program from rat heart has greatly guaranteed the quality of blood samples, advancing and invigorating the scientific rationality of the research on systemic cardiovascular diseases and evaluating ethnomedicine therapy from the perspective of hematology.

Introduction

With the acceleration of the pace of life and the increase of psychological pressure, cardiovascular diseases (CVDs) tend to occur in young, middle-aged, and elderly people^1,2. The morbidity and mortality of CVDs are high, with the characteristics of acute onset, rapid progression, and a long course of the disease, which seriously affect the safety of patients³. The occurrence of CVDs may be closely related to the changes in some blood components, such as cholesterol, serum lipids, blood glucose, myocardial enzymes, and protein kinase K^4,

Protocol

The animal protocol has been approved by the Administrative Committee of Chengdu University of Traditional Chinese Medicine (Record number: 2021-11). Specified pathogen-free male Sprague Dawley (SD) rats (8-10 weeks, 260-300 g) were raised in independent ventilation cages, maintaining the laboratory environment at 22 °C and 65% relative humidity, and were used for the present study. The animals were obtained from a commercial source (see Table of Materials). All rats were habituated to adaptive feeding for 1 week with free water and diet during the period.

1. Experimental preparation

1. Assemb....

Results

The present protocol allowed obtaining the cardiac blood from conscious rats according to sampling parameters set in the microdialysis equipment. Normal blood samples must be bright red, while animals with hypoxia, potential blood clots, or anemic disease may have dark purple or dark red. Samples obtained through the blood microdialysis technique are colorless, clear, and transparent, which can be used to analyze the serum markers of different diseases and the blood distribution of drugs and their metabolites by employin.......

Discussion

CVDs are a common chronic disease in clinics with gradually increasing incidence in China, and the onset age tends to be younger, causing the concern and panic of most patients^20,21. Being the leading cause of death in the world, CVDs can induce cerebral infarction and other high mortality diseases, seriously threatening the healthy life of patients²². CVDs, including ischemic heart disease, cardiomyopathy, atherosclerosis, high blood pres.......

Materials

List of materials used in this article

Name	Company	Catalog Number	Comments
Animal anesthesia system	Rayward Life Technology Co., Ltd	R500IE
Animal temperature maintainer	Rayward Life Technology Co., Ltd	69020
Blood microdialysis probe	CMA Microdialysis AB	T55347
Catheter	CMA Microdialysis AB	T55347
Citrate	Merck Chemical Technology (Shanghai) Co., Ltd	251275
Electric shaver	Rayward Life Technology Co., Ltd	CP-5200
Fep tubing	CMA Microdialysis AB	3409501
Free movement tank for animals	CMA Microdialysis AB	CMA120
Glucose	Merck Chemical Technology (Shanghai) Co., Ltd	G8270
Hemostatic forceps	Rayward Life Technology Co., Ltd	F21020-16
Isofluran	Rayward Life Technology Co., Ltd	R510-22
Micro scissors	Beyotime Biotechnology Co., Ltd	FS221
Microdialysis collection tube	CMA Microdialysis AB	7431100
Microdialysis collector	CMA Microdialysis AB	CMA4004
Microdialysis in vitro stand	CMA Microdialysis AB	CMA130
Microdialysis microinjection pump	CMA Microdialysis AB	788130
Microdialysis syringe (1.0 mL)	CMA Microdialysis AB	8309020
Microdialysis tubing adapter	CMA Microdialysis AB	3409500
Microporous filter membrane	Merck Millipore Ltd.	R0DB36622
Non-absorbable surgical sutures	Shanghai Tianqing Biological Materials Co., Ltd	S19004
Operating table	Yuyan Scientific Instrument Co., Ltd	30153
Ophthalmic forceps	Rayward Life Technology Co., Ltd	F12016-15
Sodium citrate	Merck Chemical Technology (Shanghai) Co., Ltd	1613859
Sprague Dawley  (SD) rats	Chengdu Dossy Experimental Animals Co., Ltd	SYXK()2019-049
Surgical scissors	Rayward Life Technology Co., Ltd	S14014-15
Surgical scissors	Shanghai Bingyu Fluid technology Co., Ltd	BY-103
Syringe needle	CMA Microdialysis AB	T55347
Ultrasonic cleaner	Guangdong Goote Ultrasonic Co., Ltd	KMH1-240W8101