[Neonatal biliary peritonitis].
Explore the source record for details and available documents.
Biomedical subjects
Publications and source records attributed to F Rivilla.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
The effect of experimental subarachnoid hemorrhage (SAH) on the adrenergic innervation and on the 45Ca2+ uptake of cat cerebral arteries was analyzed. Intracisternal injections of autologous blood reduced the noradrenaline content of perivascular nerve endings and 3H-noradrenaline uptake. These values returned to normal levels in a period of two weeks after SAH. The activity of dopamine-beta-hydroxylase was also reduced 3 and 7 days after SAH. Superior cervical gangliectomy and intracisternal injection of 6-hydroxydopamine also reduced these three parameters. The uptake of 45Ca2+ by arteries from animals submitted to SAH was greater than if the blood vessels were from untreated cats. Lantanum brought about a less 45Ca2+ displacement in the arterial segments from untreated animals than in those from cats after SAH. These results suggest that SAH induces a transient adrenergic denervation as well as changes in the membrane of smooth muscle cell which increase the quantity of Ca2+ bound to it. All these modifications might be involved in the cause of chronic cerebral vasospasm that appears after SAH.
1. The cerebral vessels possess adrenergic, cholinergic, serotonergic and peptidergic innervations. 2. The cerebral vessels have alpha- and beta-adrenergic, cholinergic, serotonergic, histaminergic H1 and H2 and dopaminergic receptors whose activation by different agents causes vasomotor responses. 3. The induced effects by noradrenaline, adrenaline and serotonin are characterized by a cerebral vasoconstriction clearly manifested in man, the awake or anesthetized animal and isolated vessels. The vasoconstrictor response generally obeys an activation of specific receptors. 4. Under experimental conditions acetylcholine, histamine, dopamine and isoproterenol relax these vessels, in which cholinergic, H2-histaminergic, dopaminergic and beta-adrenergic (beta 1) receptors are implicated, respectively.
The effect of removal of the left superior cervical ganglion on the contractile response to norepinephrine (NE) and 5-hydroxytryptamine (5-HT, serotonin) was studied in isolated segments of the middle cerebral artery (MCA) and posterior communicating artery (PCoA) of the cat. Fifteen days after the excision, each dose of NE elicited a potentiated response in both the MCA and the PCoA, whichever side they originated. By contrast, 5-HT induced enhanced vasoconstriction at each dose only in the MCA and PCoA from the left side. When segments of MCA and PCoA from the right side were challenged against 5-HT, a significantly increased response was found only at the first three doses. On the other hand, the NE content of pools made of MCA, PCoA, and anterior cerebral artery from each side was reduced to the same level on both sides after ganglion removal. These results indicate that the excised superior cervical ganglion innervated the MCA and PCoA from both sides of the circle of Willis.
The effect of subarachnoid hemorrhage (SAH) on the adrenergic innervation of cat cerebral arteries was analyzed. Intracisternal injections of autologous blood reduced the noradrenaline content from the perivascular nerves. Dopamine beta-hydroxylase and the uptake of 3H-noradrenaline were also decreased. These changes returned to normal in a period of 2 to 3 weeks after the SAH. Superior cervical ganglionectomy and intracisternal injections of 6-hydroxydopamine also reduced these three parameters. It is suggested that SAH induces a transient adrenergic denervation of the cerebral arteries that might be involved in the production of the chronic cerebral vasospasm.
This study analyzes the time course of the changes induced by subarachnoid hemorrhage (SAH) in the sensitivity of cat cerebral arteries to noradrenaline and serotonin. Cerebral arteries to noradrenaline and serotonin. Cerebral arteries displayed a supersensitivity to these amines, which was most marked 3 days after the experiment and then gradually disappeared. The supersensitivity to serotonin was greater and longer than the response to noradrenaline. The increase in the vascular contractile response induced by SAH was similar to that seen after superior cervical ganglionectomy or intracisternal injections of 6-hydroxydopamine. It is suggested that supersensitivity to noradrenaline and serotonin induced by SAH may be involved in the production of chronic cerebral vasospasm.
Explore the source record for details and available documents.
Explore the source record for details and available documents.