title: Cerebral blood flow during hemorrhagic hypotension in the unanesthetized goat.
abstract: Changes in cerebral blood flow (CBF), arterial blood pressure (AP), and cardiac output (CO) were studied during stepwise blood losses in 12 unanesthetized goats. Bleeding was followed by a drop in CBF, AP and CO in a nearly parallel fashion. Control values (means +/- SE) for CBF, AP, and CO were 117 +/- 5.6 ml/min per 100 g, 105 +/- 3.1 mmHg, and 2,825 +/- 124 ml/min, respectively; and after bleeding, 66 +/- 3.9 ml/min per 100 g, 57 mmHg, and 1, 383 ml/min. Arterial blood samples obtained before bleeding, during the hypotensive state, and after reinfusion did not show any significant differences in pH, PCO2, and PO2 values. In phentolamine-treated animals, bleeding produced a drop in AP and CO similar to that observed in the nontreated animals; however, the decrease in CBF was less marked. These findings show that CBF follows pari passu the fall in AP, and they indicate that the alpha-adrenergic receptors of the cerebral vessels are involved in the cerebral blood flow changes in hemorrhage.
mesh_terms: D000818:Animals; D001794:Blood Pressure / Q000187:drug effects; D002302:Cardiac Output / Q000187:drug effects; D002560:Cerebrovascular Circulation / Q000187:drug effects; D005260:Female; D006041:Goats; D006470:Hemorrhage / Q000150:complications / Q000503:physiopathology*; D007022:Hypotension / Q000209:etiology / Q000503:physiopathology; D010646:Phentolamine / Q000494:pharmacology
chemical_list: D010646:Phentolamine