[Effects of sodium hyaluronate on the nociceptive response of rats with experimentally induced arthritis].
Antinociceptive effects of sodium hyaluronate (Na-HA) were studied on the basis of improvement in the graded abnormal gait elicited by arthritis induced by intra-articular administration of monosodium urate crystal (MSU) to rats. One hour before MSU injection, intra-articular administration of a 1.0% solution of Na-HA with different molecular weights, ranging from 4.70 x 10(5) to 2.02 x 10(6) (HA-200), improved the score of abnormal gait in a molecular weight-dependent manner in the experimental arthritis model. Similarly, administrations of HA-200 at concentrations ranging from 0.1 to 1.0% prior to MSU treatment resulted in improvement of the score in abnormal gait in a dose-dependent manner. To elucidate the antinociceptive mechanisms of Na-HA, effects of pretreatment with Na-HA (1.0%) of different molecular weights on prostaglandin E2 (PGE2) and bradykinin (BK) releases in synovial fluid 3 hr after MSU injection were studied. Increases in PGE2 and BK concentration in the synovial fluid were depressed in a molecular weight-dependent manner by Na-HA (1.0%) pretreatment. These results indicate that Na-HA attenuates the nociceptive responses inflicted by the MSU-induced arthritis. Such an antinociceptive effect may be due to the inhibition of PGE2 and BK synthesis in the synovial joint of rats.
Aihara
S
S
Division of Pharmacology, Research Laboratories, Maruho Co., Ltd., Osaka, Japan.
Murakami
N
N
Ishii
R
R
Kariya
K
K
Azuma
Y
Y
Hamada
K
K
Umemoto
J
J
Maeda
S
S
D000700:Analgesics / Q000494:pharmacology / Q000627:therapeutic use*; D000818:Animals; D001168:Arthritis / Q000139:chemically induced / Q000188:drug therapy* / Q000378:metabolism; D001920:Bradykinin / Q000378:metabolism; D015232:Dinoprostone / Q000378:metabolism; D006820:Hyaluronic Acid / Q000737:chemistry / Q000494:pharmacology / Q000627:therapeutic use*; D008297:Male; D008970:Molecular Weight; D051381:Rats; D017208:Rats, Wistar; D013582:Synovial Fluid / Q000378:metabolism; D014527:Uric Acid
D000700:Analgesics; D014527:Uric Acid; D006820:Hyaluronic Acid; D015232:Dinoprostone; D001920:Bradykinin