RESEARCH ARTICLE
The Role of Different Hyaluronic Acids in the Articular Cartilage of Rabbit
Jaime Antonio Sánchez Lázaro*, Pilar Coronel Granado, Mercedes Gimeno del Sol, Ana González Medina, Luis Díaz Gállego, Daniel González-Arabio Sandoval, Julio Gabriel Prieto Fernández
Article Information
Identifiers and Pagination:
Year: 2010Volume: 4
First Page: 44
Last Page: 47
Publisher ID: TOORTHJ-4-44
DOI: 10.2174/1874325001004010044
Article History:
Received Date: 11/11/2009Revision Received Date: 24/11/2009
Acceptance Date: 3/10/2009
Electronic publication date: 19/1/2010
Collection year: 2010

open-access license: This is an open access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.5/) which permits unrestrictive use, distribution, and reproduction in any medium, provided the original work is properly cited.
Abstract
Purpose:
To elucidate if the differences found in the physico-chemical and rheological behaviour of Hyaluronic Acids result in different in vivo activity. For this purpose two Hyaluronic Acids (HA), HA-1 and HA-2, with similar molecular weight but different percentage of concentration variation, were compared through an osteoarthritis model.
Methods and Materials:
Osteoarthritis was induced in white New Zealand rabbits by anterior cruciate ligament section. After the induction period, the animals were allocated to receive HA-1 or HA-2 intra-articularly in one knee whereas the contralateral knee was used as Operated Control. An additional group of non-operated animals was used as Healthy Controls. Samples of cartilage were taken for different measures: apoptosis, nitric oxide (nitrites) and hyaluronic acid in synovial fluid.
Results:
The administration of HA-1 had a significant inhibitor effect on apoptosis of the chondrocytes compared to operated untreated animals (p = 0.0089), whereas this difference was not observed in the HA-2 knees. Levels of nitrites determined by HPLC in the HA-1 knees were similar to those in the Healthy group (p = 0.6551) whereas they were significantly higher in Operated Control and HA-2 groups (p = 0.0001). The comparison between HA-1 and HA-2 also revealed significantly lower levels of nitrites in the HA-1 knees (p = 0.0001). Values of hyaluronic acid in synovial fluid did not show statistical differences between the different study groups.
Conclusions:
HA-1 and HA-2 showed different physico-chemical characteristics and these differences have resulted in different in vivo behaviour. As a consequence, not all the HA with similar molecular weight can be considered as equivalent.