Evidence for a neural source of acute accumulation of serotonin in platelets in the injured spinal cord of rats. An experimental study using 5,6-dihydroxytryptamine treatment.
It was found previously that large numbers of platelets showing high serotonin (5-hydroxytryptamine; 5-HT) immunoreactivity appeared in hemostatic plugs at the traumatized cord segment in the acute phase of a trauma. In order to determine the origin of 5-HT in the platelets, we investigated the 5-HT immunoreactivity of platelets accumulating in hemostatic plugs at the traumatized spinal cord segment at 5 minutes after injury. This investigation was carried out by light and electron microscopic immunohistochemistry in rat spinal cord pretreated with 5,6-dihydroxytryptamine (5,6-DHT). The hemorrhagic lesion formed at the neural 5-HT-depleted spinal cord segment was completely 5-HT immunonegative, while platelets in lesions in cord segments of control animals or rostral to the injection site of 5,6-DHT in experimental animals where neural 5-HT was not depleted were 5-HT immunoreactive. The results strongly suggest that a significant amount of 5-HT is released from neural elements at the injury site and is transiently incorporated into the platelets in situ.
Saruhashi
Y
Y
Department of Orthopedic Surgery, Shiga University of Medical Science, Seta Otsu, Japan.
Hukuda
S
S
Maeda
T
T
D015115:5,6-Dihydroxytryptamine / Q000633:toxicity*; D000818:Animals; D001792:Blood Platelets / Q000187:drug effects / Q000378:metabolism* / Q000648:ultrastructure; D006470:Hemorrhage / Q000097:blood / Q000473:pathology; D006487:Hemostasis; D008297:Male; D051381:Rats; D011919:Rats, Inbred Strains; D012701:Serotonin / Q000097:blood*; D013116:Spinal Cord / Q000473:pathology; D013119:Spinal Cord Injuries / Q000097:blood* / Q000139:chemically induced / Q000473:pathology
D012701:Serotonin; D015115:5,6-Dihydroxytryptamine