Effects of a serotonin S2-receptor blocker on healing of acute and chronic tendon injuries.
The beneficial effects of serotonin S(2)-receptor blockers on healing skin and muscle ulcers and refractory lesions such as leprosy and diabetic and ischemic ulcers have been reported previously, but their mechanisms of actions are not clear. The present study sought to elucidate the action of an S(2)-receptor blocker, metrenperone, on the healing of collagenase-induced injuries in superficial digital flexor tendons of two groups of rabbits. In one group, oral and topical therapy for 28 days with metrenperone, was started within 48 hr of a single acute injury. The animals were then left untreated for another 60 days, when it was found that most of the morphological, biochemical, and biomechanical characteristics of the healed tendons matched those of their normal uninjured controls. Injured, untreated controls showed poor healing. In the second group of animals, tendon injury was induced by four separate injections of collagenase at weekly intervals. The rabbits were left for another 60 days, before being treated with metrenperone for 26 days. This delayed treatment had no apparent effect on the biomechanical, biochemical, or morphological characteristics of the healing tendons. It appeared that metrenperone had a significant effect on collagen turnover and organization of scar tissue, but only while the inflammatory and fibroplastic processes were active in the early stages of healing. S(2)-receptor blockers may, therefore, be of potential value for modulating repair in acutely injured collagenous tissue.
Oryan
Ahmad
A
Department of Pathobiology, Veterinary School, Shiraz University, Shiraz, Iran. oryan@shirazu.ac.ir
Silver
Ian A
IA
Goodship
Allen E
AE
D000284:Administration, Oral; D000287:Administration, Topical; D000818:Animals; D001696:Biomechanical Phenomena; D005260:Female; D010880:Piperidines / Q000008:administration & dosage / Q000627:therapeutic use*; D011817:Rabbits; D058830:Serotonin 5-HT2 Receptor Antagonists; D012702:Serotonin Antagonists / Q000627:therapeutic use*; D013708:Tendon Injuries / Q000188:drug therapy* / Q000473:pathology; D013710:Tendons / Q000187:drug effects; D014945:Wound Healing / Q000187:drug effects*
D010880:Piperidines; D058830:Serotonin 5-HT2 Receptor Antagonists; D012702:Serotonin Antagonists; C046881:metrenperone