02322nas a2200301   4500000000100000008004100001260001700042653002500059653002800084653001200112653002800124653001100152653001600163653001200179653004100191653002600232653002000258653001200278653001800290100001200308700001300320700001600333245009600349300001100445490000700456520154300463022001402006       2009                            d  c2009 Jul-Aug10aAdministration, Oral10aAdministration, Topical10aAnimals10aBiomechanical Phenomena10aFemale10aPiperidines10aRabbits10aSerotonin 5-HT2 Receptor Antagonists10aSerotonin Antagonists10aTendon Injuries10aTendons10aWound Healing1 aOryan A1 aSilver I1 aGoodship AE00aEffects of a serotonin S2-receptor blocker on healing of acute and chronic tendon injuries.  a246-550 v223 a<p>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.</p>  a1521-0553