Role of 5-hydroxytryptamine in the progression of monocrotaline induced pulmonary hypertension in rats.
OBJECTIVE
The aim was to clarify the role of serotonin (5-hydroxytryptamine, 5-HT) in monocrotaline induced pulmonary hypertension.


METHODS
Plasma 5-HT levels, pulmonary capillary platelet count, and vascular responsiveness to 5-HT were evaluated in the model. The effects of the selective 5-HT2 receptor antagonist, DV-7028, on the development of pulmonary hypertension were also investigated.


RESULTS
Plasma 5-HT was raised 12 h to 3 d after monocrotaline administration (60 mg.kg-1), coinciding with accumulation of platelets in the pulmonary circulation. Isolated pulmonary arteries showed hyperreactivity to 5-HT at 14 and 21 d after monocrotaline. Administration of DV-7028 (20 mg.kg-1 x d-1) attenuated the increase in pulmonary arterial pressure, right ventricular hypertrophy, and medial thickening of the pulmonary arteries.


CONCLUSIONS
The present study suggests that 5-HT released from platelets contributes to the initiation and progression of monocrotaline induced pulmonary hypertension.
Kanai
Y
Y
Keio University School of Medicine, Tokyo, Japan.
Hori
S
S
Tanaka
T
T
Yasuoka
M
M
Watanabe
K
K
Aikawa
N
N
Hosoda
Y
Y
D000818:Animals; D001792:Blood Platelets / Q000648:ultrastructure; D046508:Culture Techniques; D006976:Hypertension, Pulmonary / Q000097:blood / Q000139:chemically induced* / Q000473:pathology; D008168:Lung / Q000648:ultrastructure; D008297:Male; D016686:Monocrotaline / Q000633:toxicity*; D010880:Piperidines / Q000494:pharmacology; D010976:Platelet Count; D011651:Pulmonary Artery / Q000187:drug effects; D051381:Rats; D012701:Serotonin / Q000097:blood / Q000494:pharmacology / Q000502:physiology*; D012702:Serotonin Antagonists / Q000494:pharmacology; D014227:Triazines / Q000494:pharmacology
D010880:Piperidines; D012702:Serotonin Antagonists; D014227:Triazines; C073727:DV 7028; D012701:Serotonin; D016686:Monocrotaline