ZDF fa/fa rats show increasing heterogeneity in main parameters during ageing as confirmed by biometrics, oxidative stress markers and MMP activity.
Exp Physiol 2022;
107:1326-1338. [PMID:
36039019 DOI:
10.1113/ep090455]
[Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2022] [Accepted: 08/26/2022] [Indexed: 11/08/2022]
Abstract
NEW FINDINGS
What is the central question of this study? To characterize ZDF fa/fa rats and two controls (Wistar and lean ZDF fa/+) during ageing. What is the main finding and its importance? ZDF fa/fa rats with lower glycaemia have a greater body and left ventricular weight, and lower plasma gelatinase activity compared with hyperglycaemic rats. As diabetes represents a heterogeneous metabolic disorder, the inhomogeneity of ZDF fa/fa rats may be beneficial in the study of its different aspects. Our experiments may promote a discussion regarding the suitable normoglycemic control for aged ZDF fa/fa rats, especially in experiments focused on myocardial tissue.
ABSTRACT
Zucker diabetic fatty rats (ZDF fa/fa) - an animal model for the study of type 2 diabetes (T2D), are considered as a uniform group in most experimental studies; however, there are indices regarding their growing inhomogeneity over time. The main objective of our study was to monitor particular biometric and biochemical parameters of ZDF fa/fa rats during development to T2D and compare them with two controls (Wistar and lean ZDF fa/+). According to fasting glycaemia, ZDF fa/fa were arbitrarily split into two phenotypes - obese ZDF (fa/fa)-FAT and diabetic ZDF (fa/fa)-DIA. Glycaemia was progressively rising only in ZDF (fa/fa)-DIA which also exhibited higher cholesterol levels compared with ZDF (fa/fa)-FAT. In addition, ZDF (fa/fa)-FAT revealed more pronounced left ventricular hypertrophy and greater body weight, differentiating them from ZDF (fa/fa)-DIA. Moreover, we investigated the activity of matrix metalloproteinases (MMPs), multifunctional enzymes involved in tissue remodelling. Rats in the ZDF (fa/fa)-FAT group revealed lower plasma MMP-2 and MMP-9 activity compared with ZDF (fa/fa)-DIA. However, increased myocardial MMP-2 activity indicated left ventricular remodelling in both ZDF phenotypes. As T2D in humans represents a heterogeneous metabolic disorder, the heterogeneity of ZDF fa/fa rats may be beneficial in the study of different aspects of this pathology. Moreover, Wistar rats could serve as a more appropriate control for aged ZDF fa/fa rats than commonly used fa/+ rats that showed an increase in left ventricular weight, carbonyl stress markers in the left myocardium and MMP-2 activity in both ventricles, indicating heart remodelling processes compared with the Wistar control group. This article is protected by copyright. All rights reserved.
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