title: Nicardipine, a calcium antagonist, does not aggravate intracerebral haemorrhage in an intracerebral haemorrhage model in rats.
abstract: Despite controversy over their safety in patients with intracerebral haemorrhage, calcium antagonists are widely used in the treatment of hypertensive emergencies. Here, we investigated the effects of nicardipine on haematoma size and neurological deficit in a rat model of collagenase-induced intracerebral haemorrhage. Injection of collagenase (0.014 U) into the striatum induced haematoma (19.9+/-3.4 mm(3)) in the striatum and brain oedema. Drugs were infused from 30 min after collagenase injection for 3 h under conscious conditions. Nicardipine intravenously at 0.1, 1 and 10 microg kg(-1) min(-1) affected neither haematoma size nor the degree of brain oedema. Nicardipine at these doses provided a stable and dose-dependent decrease in mean blood pressure of 6%, 13% and 33%, respectively, with an increase in heart rate that was apparently caused reflexively. Further, nicardipine did not aggravate the neurological deficits in these intracerebral haemorrhage rats, primarily forearm flexion behaviour on suspension by the tail and circling behaviour. These results indicate that nicardipine infusion stably decreased blood pressure without affecting intracerebral haemorrhage in an intracerebral haemorrhage model in rats.
authors.affiliation: Applied Pharmacology Research, Pharmacology Laboratories, Yamanouchi Pharmaceutical Co. Ltd, Ibaraki, Japan. suzuki_m@yamanouchi.co.jp
authors.forename: Masanori
authors.initials: M
authors.lastname: Suzuki
authors.forename: Aska
authors.initials: A
authors.lastname: Hayashi
authors.forename: Masao
authors.initials: M
authors.lastname: Sasamata
mesh_terms: D000818:Animals; D000959:Antihypertensive Agents / Q000627:therapeutic use*; D001794:Blood Pressure / Q000187:drug effects; D002121:Calcium Channel Blockers / Q000627:therapeutic use*; D002543:Cerebral Hemorrhage / Q000139:chemically induced / Q000188:drug therapy*; D017364:Collagenases; D004195:Disease Models, Animal; D006339:Heart Rate / Q000187:drug effects; D006406:Hematoma / Q000188:drug therapy*; D008297:Male; D009529:Nicardipine / Q000008:administration & dosage / Q000627:therapeutic use*; D051381:Rats; D017207:Rats, Sprague-Dawley
chemical_list: D000959:Antihypertensive Agents; D002121:Calcium Channel Blockers; D009529:Nicardipine; D017364:Collagenases