ABSTRACT
The author attempted to clarify the nature of alpha-adrenoceptors in relation to the pressor response to the increased intracranial pressure(ICP) in urethane-anesthetized rabbits, using the epidural balloon method. 1) The blood pressure increased in parallel with the raised ICP which was made by gradual inflation of the balloon. 2) B-HT 920, an alpha2-agonist, which elicited depressor and bradycardiac responses in normal rabbits inhibited markedly the pressor response to the raised ICP. 3) Piperoxan, an alpha2-antagonist, potentiated the pressor response to the raised ICP. 4) Piperoxan antagonized the depressor and bradycardiac responses by B-HT 920 as well as the inhibitory effect of B-HT 920 on the pressor response to the raised ICP. 5) The pressor response to the raised ICP were not affected at all by prazosin, an alpha1-antagonist. 6) Neither the depressor and bradycardiac responses by B-HT 920 itself nor the inhibitory effect of B-HT 920 on the pressor response to the raised ICP were significantly affected by prazosin. It is inferred from these observations that the central alpha-adrenoceptors play an important role in producing the pressor response to the raised ICP and that the receptors involved here seems to be of alpha2-type.
Subject(s)
Rabbits , Blood Pressure , Inflation, Economic , Intracranial Pressure , Piperoxan , PrazosinABSTRACT
The author attempted to clarify the nature of alpha-adrenoceptors in relation to the pressor response to the increased intracranial pressure(ICP) in urethane-anesthetized rabbits, using the epidural balloon method. 1) The blood pressure increased in parallel with the raised ICP which was made by gradual inflation of the balloon. 2) B-HT 920, an alpha2-agonist, which elicited depressor and bradycardiac responses in normal rabbits inhibited markedly the pressor response to the raised ICP. 3) Piperoxan, an alpha2-antagonist, potentiated the pressor response to the raised ICP. 4) Piperoxan antagonized the depressor and bradycardiac responses by B-HT 920 as well as the inhibitory effect of B-HT 920 on the pressor response to the raised ICP. 5) The pressor response to the raised ICP were not affected at all by prazosin, an alpha1-antagonist. 6) Neither the depressor and bradycardiac responses by B-HT 920 itself nor the inhibitory effect of B-HT 920 on the pressor response to the raised ICP were significantly affected by prazosin. It is inferred from these observations that the central alpha-adrenoceptors play an important role in producing the pressor response to the raised ICP and that the receptors involved here seems to be of alpha2-type.
Subject(s)
Rabbits , Blood Pressure , Inflation, Economic , Intracranial Pressure , Piperoxan , PrazosinABSTRACT
1. It was attempted to clarify the mechanism of the pressor response to raised intracranial pressure in urethane-anesthetized rabbits. 2. Intraventricular clonidine markedly inhibited the pressor response to raised intracranial pressure. 3. Intraventricular regitine antagonized the above mentioned inhibitory effect of clonidine on the pressor response. 4. In reserpine-treated rabbits the pressor response to raised intracranial pressure was not observed, whereas after the intraventricular administration of norepinephrine the pressor response was observed. 5. Intraventricular clonidine inhibited the pressor response that could be observed in the reserpine-treated rabbits after the intraventricular norepinephrine. 6. It is inferred that raised intracranial pressure stimulated some part of the brain to cause the increase of norepinephrine release, resulting in the increase of the sympathetic outflow and the elevation of blood pressure.
Subject(s)
Rabbits , Blood Pressure , Brain , Clonidine , Intracranial Pressure , Norepinephrine , PhentolamineABSTRACT
The authors reported a case of a dumbbell-shaped meningioma which originated from the falx. A six-year-old girl was admitted to our clinic with generalized convulsion, headache, vomiting, visual disturbance and motor wakness of the left extremity. Neurological examinations revealed the left hemiparesis with hyperactive deep tendon reflex and marked papilledema. The skull films showed prominent diastasis of the coronal and sagittal sutures and abnormal calcification in the frontal region. The right carotid angiogram showed a huge irrgular tumor vascularity in the midfrontal region. On Nov. 5, 1977 a right frontal craniotomy was carried. A large dumbbell-shaped tumor was removed which arised from the falx cerebri. Each tumor measured 5x5x6 cm, 6x6x7 cm respectively and weighed 110 gm totally. The histopathological examination comfirmed the diagnosis of fibroblastic meningioma. Postoperative course was uneventful and the patient was discharged on the 14 th hospital day. The patient was seen 6 months after operation without any symptom.
Subject(s)
Female , Humans , Craniotomy , Diagnosis , Extremities , Fibroblasts , Headache , Meningioma , Neurologic Examination , Papilledema , Paresis , Reflex, Stretch , Seizures , Skull , Sutures , VomitingABSTRACT
Intracranial subdural empyema is a relatively uncommon complication of paranasal sinusitis and otitic infection. It manifests itself by headache, neck stiffness and pyrexia, symptoms and signs of acutely increased intracranial pressure, convulsions, aphasia and other focal neurological signs. Recently, we have operated upon two cases of intracranial subdural empyema secondary to acute frontal sinusitis and traumatic scalp laceration respectively. Reviewing these two cases and other literatures, we are going to describe about causes, symptoms and signs, and methods of diagnosis and treatment of subdural empyema.
