ABSTRACT
We sought to determine the effects of activation of peroxisome proliferator-activated receptor-gamma (PPAR-gamma) on multilocularization of adipocytes in adult white adipose tissue (WAT). Male C57BL/6 normal, db/db, and ob/ob mice were treated with agonists of PPAR-gamma, PPAR-alpha, or beta3-adrenoceptor for 3 weeks. To distinguish multilocular adipocytes from unilocular adipocytes, whole-mounted adipose tissues were co-immunostained for perilipin and collagen IV. PPAR-gamma activation with rosiglitazone or pioglitazone induced a profound change of unilocular adipocytes into smaller, multilocular adipocytes in adult WAT in a time-dependent, dose-dependent, and reversible manner. PPAR-alpha activation with fenofibrate did not affect the number of locules or remodeling. db/db and ob/ob obese mice exhibited less multilocularization in response to PPAR-gamma activation compared to normal mice. Nevertheless, all adipocytes activated by PPAR-gamma contained a single nucleus regardless of locule number. Multilocular adipocytes induced by PPAR-gamma activation contained substantially increased mitochondrial content and enhanced expression of uncoupling protein-1, PPAR-gamma coactivator-1-alpha , and perilipin. Taken together, PPAR-gamma activation induces profound multilocularization and enhanced mitochondrial biogenesis in the adipocytes of adult WAT. These changes may affect the overall function of WAT.
Subject(s)
Animals , Male , Mice , Adipocytes/cytology , Adipose Tissue, White/cytology , Cell Nucleus Division , Hypoglycemic Agents/pharmacology , Ion Channels/metabolism , Mice, Inbred C57BL , Mice, Obese , Mitochondria/metabolism , Mitochondrial Proteins/metabolism , PPAR alpha/agonists , PPAR gamma/agonists , Phosphoproteins/metabolism , Receptors, Adrenergic, beta-3/agonists , Thiazolidinediones/pharmacology , Trans-Activators/metabolismABSTRACT
Biological effects of microwave radiation on living creatures have been the focus of many investigations over the last decade and the influence of different wave parameters such as frequency, power, exposure time, and modulation has been elucidated. The main purpose of the present study was to investigate the effect of microwave radiation on alterations of micronucleus induction and nuclear divisions index under different conditions. A total of 48 Balb/c mice divided in eight groups [7 as cases and 1 as control] were exposed to microwave generator while restrained in specially designed Plexiglas chamber. Later, the frequency of micronucleus in binucleated lymphocytes and NDI was evaluated using micronucleus assay on mouse lymphocytes. Microwave radiation conditions [frequency, power, modulation and exposure time] showed no significant effect on frequency of micronucleus, however, the nuclear division index was significantly decreased under such conditions. Based on data found in our study, the microwave radiation as we used during the present work, caused significant effect on nuclear division index in mouse lymphocytes