| Disease | REPIN IS A SESQUITERPENE LACTONE FOUND IN CENTAUREA SOLSTITIALIS, A PLANT RESPONSIBLE FOR PARKINSON-LIKE DISEASE IN HORSES. REPIN, ON INTRAPERITONEAL (I.P.) INJECTION. PRODUCES A DOSE-DEPENDENT AND HIGHLY SIGNIFICANT HYPOTHERMIA IN NAIVE RATS.
THE HYPOTHERMIA IS LONG-LASTING WITH A PEAK 3 H AFER INJECTION AND RETURN TO NORMAL TEMPERATURE AFTER MORE THAN 8 H. THE EFFECTS OF A ATROPINE SULFATE, ATROPINE METHYLBROMIDE, PROPRANOLOL, METERGOLINE, KETANSERIN, DIPHENHYDRAMINE AND APOMORPHINE
PRETREATMENT ON REPIN-INDUCED HYPOTHERMIA WERE INVESTIGATED. NONE OF THE PRETREATMENTS DIRECTLY ANTAGONIZED REPIN'S HYPOTHERMIC EFFECT. HOWEVER, PARTIAL BUT SIGNIFICANT REVERSALS OF HYPOTHERMIA BY ATROPINE SULFATE, METERGOLINE, KETANSERIN,
DIPHENHYDRAMINE AND APOMORPHINE WERE OBSERVED 2-4 H AFTER THE REPIN INJECTION. THESE LATE-ONSET EFFECTS ARE PROBABLY DUE TO SECONDARY PHYSIOLOGICAL MECHANISMS. ON THE OTHER HAND, PROPRANOLOL, AT 20 MG/KG I.P., CLEARLY ACCENTUATED BOTH THE EARLY-
ONSET(30-90 MIN) AND LATE-ONSET(2-4 H) HYPOTHERMIC EFFECTS OF REPIN. |