A comparative study of guinea pig models of endolymphatic hydrops

JIANG Zidong; GAO Fan; SUN Chengcheng

doi:10.3969/j.issn.1672-2922.2015.04.041

Abstract：Objective To compare several approaches to establishing guinea pig models of endolymphat-ic hydrops. Methods Eighty guinea pigs were divided into four groups (20 each) to undergo single ear model-ing, binaural modeling, aldosterone injection or vasopressin injection. Collodion and frozen sections of the in-ner ear were collected from surviving animals and examined under an optical microscope. The rates of animal survival and successful modeling, characteristics of cochlear hydrops, and effects of frozen or collodion sec-tions on microscopic image studies were studied. Results Both monaural and binaural modeling was success-ful in all attempted animals (24/24), although the mortality rate was 15%(3/20) for monaural modeling and 75%(15/20) for binaural modeling (P<0.05). The successful modeling rate was 89.4%(17/19) for aldosterone injection and 73.7%(14/19) for vasopressin injection, with a mortality of 5%(1/20) in both injection groups (P<0.05). Total mortality rate in surgical models was 45%(18/40), higher than injection models (5%or 2/40) (P<0.01). In surgical modeling groups, endolymphatic hydrops in cochlea was rated profound in 20 (83.3%) and moderate in 4 (16.6%) of the 24 surviving animals, while hydrops in injection modeling groups was pro-found in 8 (21%), moderate in 18 (47.3%) and mild in 12 (31.5%) of the 38 surviving animals, respectively. Both frozen and collodion sections yielded similar microscopy results. Conclusions Methods for endolym-phatic hydrops animal models should be selected according to the specific requirements of the experimental design to save cost and improve study efficacy.