ABSTRACT
Obesity is known to alter various physiological parameters including the pain sensitivity. There are conflicting reports on the pain sensitivity in obesity. In this context, the present study was aimed to investigate the tonic pain response in obese rabbit model. To achieve this aim, two groups of adult male British Angora rabbits were used. One of the groups was fed with standard rabbit chow and served as control. The other group was fed high fat diet (HFD) for 10 weeks to produce obesity. The standard formalin test was performed at the start and after 10 weeks of dietary regimen in both the groups. Timed behavioral responses (limping, elevation of paw, licking, biting, grooming etc.) were categorized and quantified with the help of standard pain rating scale. The total average pain rating score decreased significantly from 2.01 ± 0.02 to 1.47 ± 0.08 (P<0.05) in HFD group after 10 weeks of dietary regimen, whereas there was no change in the control group. A significant negative correlation was observed between body weight and pain rating score in HFD group of rabbits (P<0.05, r=–0.62). Results suggest that obesity attenuates the tonic pain responses induced by formalin in British Angora rabbits.
ABSTRACT
A reliable and cost-effective animal model for human obesity with its manifested disorders is yet to be established in the context of increased morbidity and mortality due to obesity and its related problems. Therefore, an attempt was made to produce obesity in locally available British Angora Rabbits (BAR) and examine the effect on metabolic and cardiovascular parameters. Adult male BARs weighing nearly 2 kg were randomly divided into two groups, one of the groups was fed with high fat diet (HFD) ad libitum for 10 weeks and the control group received standard normal rabbit chow for same period. Body weight, skinfold thickness, serum cholesterol, serum glucose and resting heart rate were measured before and after the dietary regimens. After 10 weeks, HFD group of rabbits demonstrated significant (P<0.05) increase in body weight (+24%) and skinfold thickness (+37%). The gain in body weight was positively correlated to skinfold thickness (r=0.61). Serum cholesterol, serum glucose and resting heart rate were also increased by 46%, 52% and 15%, respectively. Whereas no such increases in any of these parameters were observed in control group of rabbits. Our results suggest that obesity can be produced in BARs by feeding HFD. The obesity manifests with cardiovascular and metabolic changes. It is proposed that this may serve as a valid and reliable model of experimental obesity.