Effects of saline extract of ovine hydatid cyst scoleces in sheep. Blockade of responses by compound 48/80.
The effects of intravenous administration of the saline extract of the ovine hydatid cyst scoleces on the cardiovascular and respiratory systems were studied in sodium pentobarbital-anesthesized sheep. Scoleces were obtained from the lung hydatid cysts of freshly slaughtered sheep, sonicated in physiologic saline and centrifuged to recover the extract in the supernatant fluid. Administration of 1-4 ml of the saline extract resulted in hypotension, shallow rapid respiration, slight elevation of the central venous pressure and transient electrocardiographic changes. Pretreatment of the animals with atropine, 1 mg/kg S.C., or with the antihistamine antazoline, 5 mg/kg I.V., did not block the responses to the saline extract of hydatid cyst scoleces. Pretreatment with compound 48/80, a histamine releaser, abolished the reactions to the administration of the scoleces extract. It is concluded that ovine hydatid scoleces extract has profound cardiovascular and respiratory effects, and that histamine release seems to be involved in the induction of responses to the extract.
D000818:Animals; D000865:Antazoline / Q000494:pharmacology; D001285:Atropine / Q000494:pharmacology; D001794:Blood Pressure / Q000187:drug effects; D002319:Cardiovascular System / Q000187:drug effects*; D002496:Central Venous Pressure / Q000187:drug effects; D004446:Echinococcus; D004562:Electrocardiography; D012119:Respiration / Q000187:drug effects; D012137:Respiratory System / Q000187:drug effects*; D012756:Sheep; D012965:Sodium Chloride; D014020:Tissue Extracts / Q000037:antagonists & inhibitors / Q000494:pharmacology*; D003189:p-Methoxy-N-methylphenethylamine / Q000494:pharmacology*
D014020:Tissue Extracts; D003189:p-Methoxy-N-methylphenethylamine; D012965:Sodium Chloride; D001285:Atropine; D000865:Antazoline