Nemani Shivaram1, Kallamadi Prathap Reddy3, Perumalla Kiran Kumar2, Rayapoodi Naveen2, Pothani Suresh3, Nemani Harishankar3*
1Department of orthodontics and dentofacial orthopaedics, Panineeya Institute of Dental Sciences & Research Centre, Dilsukhnagar, Hyderabad, Telangana, India.
2Department of orthodontics and dentofacial orthopaedics, Mamata Dental College, Khammam, India.
3National Centre for Laboratory Animal Sciences, National Institute of Nutrition, ICMR, Telangana, Hyderabad, India.
*Correspondence:
N. Harishankar
Scientist,
National Centre for Laboratory Animal Sciences,
Jamai Osmania post, Taranaka, Hyderabad -500 007.
Abstract
Objective: WNIN/Ob is an inbred mutant obese rat strain with euglycemia developed indigenously from Wistar stock (WNIN) existing since 1920. For the first time we have studied the effect of BoNT/A on the growth, body composition and muscle conduction velocity (MCV) in WNIN/Ob mutant rats. Materials and methods: Twelve obese male rats and 12 obese female rats of 35 days of age, and age matched 24 lean rats of equal gender were taken for the study. They were randomly divided into four groups of 12 each (6 males and 6 females). Group- I was BoNT/A injected obese rats, while the group – II was BoNT/A injected lean rats, Group-III was negative control obese rats, and Group –IV was the negative control lean rats. The study continued for 45 days and parameters like growth and food intake were monitored. Body composition in control and experimental rats was determined by the total body electrical conductivity (TOBEC). MCV in lean and obese rats was determined by Biopack polygraph (MP 100 Model). Results and conclusion: BoNT/A injected obese rats showed significant decrease in food intake, body weight and fat. A significant increase in lean body mass (LBM), and fat free mass (FFM) was observed in BoNT/A injected obese rats compared to obese control rats. No significant changes were seen in food intake and growth of lean rats. MCV values were also significantly reduced on the BoNT/A treated experimental rats of both obese and lean rats as compared to their corresponding controls. The reduced MCV on the experimental side as compared to control side suggest reduced muscular function in obese rats. This was followed by a reduction in food intake leading to reduced body weight and increase in the LBM and FFM. These differences were also observed among the genders, suggesting that the muscle architecture not only varies in obese rats but also the gender.
Keywords: Fat free mass, hyperphagia, lean body mass, masseter muscle, total body electrical conductivity
LIST OF ABBERIVATIONS
BoNT/A - Botulinum neurotoxin
CD1 mice - Cluster of differentiation 1
WNIN/Ob - Wistar/NIN obese phenotype
BMI - Body mass index
TOBEC - Total body electrical conductivity
MCV - Muscle conduction velocity
LBM - Lean body mass
FFM - Fat free mass
MUP - Motor unit potentials
CMAP - Compound motor action potential
EMG - Electromyography
