Morika D Williams1, Samantha L Sommer2, Rachel C Meyers3, Juan Valdivia4, Michael W Nolan5, B Duncan X Lascelles6. 1. Department of Clinical Sciences, College of Veterinary Medicine, North Carolina State University, Raleigh, NC, United States; Translational Research in Pain Program, North Carolina State University, Raleigh, NC, United States; Comparative Medicine Institute, North Carolina State University, Raleigh, NC, United States. 2. Department of Clinical Sciences, College of Veterinary Medicine, North Carolina State University, Raleigh, NC, United States. 3. Translational Research in Pain Program, North Carolina State University, Raleigh, NC, United States. 4. Honeywell, Raleigh, NC, United States. 5. Department of Clinical Sciences, College of Veterinary Medicine, North Carolina State University, Raleigh, NC, United States; Comparative Medicine Institute, North Carolina State University, Raleigh, NC, United States. Electronic address: mwnolan@ncsu.edu. 6. Department of Clinical Sciences, College of Veterinary Medicine, North Carolina State University, Raleigh, NC, United States; Translational Research in Pain Program, North Carolina State University, Raleigh, NC, United States; Comparative Medicine Institute, North Carolina State University, Raleigh, NC, United States; Thurston Arthritis Center, University of North Carolina at Chapel Hill, Chapel Hill, NC, United States; Center for Translational Pain Medicine, Duke University, Durham, NC, United States.
Abstract
BACKGROUND: Joint pain is composed of both spontaneous and movement-induced pain. In animal models, static bodyweight distribution is a surrogate for spontaneous joint pain. However, there are no commercially-available instruments that measure static bodyweight distribution in normal, pronograde rodents. NEW METHOD: We designed a Static Horizontal Incapacitance Meter (SHIM) to measure bodyweight distribution in pronograde standing rodents. We assessed the device for feasibility, repeatability, and sensitivity to quantify hindlimb bodyweight distribution. Mice and rats with unilateral inflammatory pain induced by subcutaneous injections of capsaicin or Complete Freund's Adjuvant (CFA) into the plantar surface of the left hind paw were used to measure static weight-bearing. The ability to attenuate inflammatory pain-associated weight-bearing asymmetry was tested by administering a non-steroidal anti-inflammatory drug, meloxicam. RESULTS: The SHIM's ability to detect significant reductions in limb loading on the injected hindlimb in mice and rats was validated using both acute and sub-chronic pain models. Treatment with meloxicam partially reversed CFA-induced effects. COMPARISON WITH EXISTING METHODS: In contrast with assays that measure kinetic or static weight-bearing forces (e.g., walking, or standing at a 45 ° incline), the SHIM allows evaluation of weight-bearing in rodents that are standing at rest in their normal pronograde position. CONCLUSIONS: The SHIM successfully detected: (a) asymmetric weight-bearing in acute and sub-chronic pain models; and (b) the analgesic effects of meloxicam. This study provides a novel tool to objectively evaluate limb use dysfunction in rodents.
BACKGROUND:Joint pain is composed of both spontaneous and movement-induced pain. In animal models, static bodyweight distribution is a surrogate for spontaneous joint pain. However, there are no commercially-available instruments that measure static bodyweight distribution in normal, pronograde rodents. NEW METHOD: We designed a Static Horizontal Incapacitance Meter (SHIM) to measure bodyweight distribution in pronograde standing rodents. We assessed the device for feasibility, repeatability, and sensitivity to quantify hindlimb bodyweight distribution. Mice and rats with unilateral inflammatory pain induced by subcutaneous injections of capsaicin or Complete Freund's Adjuvant (CFA) into the plantar surface of the left hind paw were used to measure static weight-bearing. The ability to attenuate inflammatory pain-associated weight-bearing asymmetry was tested by administering a non-steroidal anti-inflammatory drug, meloxicam. RESULTS: The SHIM's ability to detect significant reductions in limb loading on the injected hindlimb in mice and rats was validated using both acute and sub-chronic pain models. Treatment with meloxicam partially reversed CFA-induced effects. COMPARISON WITH EXISTING METHODS: In contrast with assays that measure kinetic or static weight-bearing forces (e.g., walking, or standing at a 45 ° incline), the SHIM allows evaluation of weight-bearing in rodents that are standing at rest in their normal pronograde position. CONCLUSIONS: The SHIM successfully detected: (a) asymmetric weight-bearing in acute and sub-chronic pain models; and (b) the analgesic effects of meloxicam. This study provides a novel tool to objectively evaluate limb use dysfunction in rodents.
Authors: Jeffrey S Mogil; Allyson C Graham; Jennifer Ritchie; Sara F Hughes; Jean-Sebastien Austin; Ara Schorscher-Petcu; Dale J Langford; Gary J Bennett Journal: Mol Pain Date: 2010-06-08 Impact factor: 3.395
Authors: S E Bove; S L Calcaterra; R M Brooker; C M Huber; R E Guzman; P L Juneau; D J Schrier; K S Kilgore Journal: Osteoarthritis Cartilage Date: 2003-11 Impact factor: 6.576