Stress-induced release of prolactin: blockade by dexamethasone and naloxone may indicate beta-endorphin mediation

Basal levels of immunoreactive (ir) beta-endorphin, corticotropin (ACTH), and prolactin (PRL) in plasma of male rats decrease after dexamethasone pretreatment (400 microgram/kg at 24 hr and 200 microgram/kg at 2 hr before). Inescapable electric footshocks increase ir-beta-endorphin, ACTH, and PRL plasma levels and this effect is blocked by dexamethasone pretreatment. Morphine (20 mg/kg) also increases ir-beta-endorphin, ACTH, and PRL levels. Dexamethasone pretreatment blocks the morphine-induced release of ir-beta-endorphin but does not prevent the morphine-induced release of PRL. Naloxone, the opiate antagonist, decreases basal plasma levels of PRL and partially blocks the stress-induced increase of PRL, but it has no effect on the basal or stress-induced release of ir-beta-endorphin. These results are consistent with the proposal that beta-endorphin may interact with an opiate receptor involved in the regulation of PRL secretion.

Opioid peptides and alpha-melanocyte-stimulating hormone in genetically obese (ob/ob) mice during development

Compared to littermate controls (C57BL/6J ob/?), body weights of genetically obese (ob/ob) mice are significantly higher at 1-6 months of age; the greatest percentage weight gain of the ob/ob group occurs during the first 3 months of life. Levels of pituitary immunoreactive beta-endorphin and immunoreactive alpha-melanocyte-stimulating hormone are also significantly elevated in ob/ob animals compared to controls. However, these pharmacological differences only emerge at 4-6 months of age--3 months after the appearance of obesity. High levels of immunoreactive endorphin in the pituitary are, therefore, more likely to be a consequence than a cause of obesity. Furthermore, numerous other neurologic abnormalities, which may or may not play a role in the obesity syndrome, are evident in ob/ob mice. Compared to controls, ob/ob total brain, hypothalamus, and pituitary weights are 11%, 16%, and 23% less, respectively. Levels of immunoreactive Leu5-enkephalin in pars nervous are also 200% higher in ob/ob mice; this increase is apparent at 1-6 months of age and is highly correlated with changes in body weight.

[Extraneural metastases of malignant brain tumors through ventriculoperitoneal shunt--report of two autopsy cases and a review of the literature (author's transl)]

Internal drainage of cerebrospinal fluid utilizing a mechanical tube has been an increasingly common and effective procedure for the relief of non-communicating hydrocephalus with intracranial tumor. However, several cases have recently been reported in which extraneural metastases of the tumor were initiated through the shunt tube implanted. The purpose of this paper is to present two cases with malignant brain tumor metastasizing extraneurally through ventriculoperitoneal shunt, and to review the reported cases in the literature. Case 1 The patient, a 9-year-old boy, had been suffering from headache and vomiting for 3 months prior to admission to the Neurosurgical Clinic, Gumma University Hospital. On admission, he had choked discs and cerebellar dysfunction with a staggering gait. The clinical diagnosis was a 4th ventricle tumor. On November 29, 1971, a suboccipital craniectomy was performed. A medullary tumor in the 4th ventricle was partially removed, and ventriculoperitoneal shunt was also performed. Subsequently postoperative irradiation was given, and the symptoms were abated. Histological diagnosis was ependymoblastoma. Thirteen months later, he was again admitted because of visual disturbance, psychic change and pituitary hypofunction. Bilateral frontal craniotomy revealed a large mass over the midline of the anterior skull base, accompanied by numerous meningeal neoplastic deposits. The tumor was partially removed and histologically proven to be meningeal metastases of ependymoblastoma. Irradiation was again given and the symptoms improved. But the 4th ventricle tumor recurred 5 months after the 2nd operation, and then a massive intraperitoneal effusion appeared. Cytological examination revealed clusters of tumor cells in the ascites. The patient died on September 8, 1974, namely 22 months after the ventriculoperitoneal shunt was implanted. Postmortem examination showed a solid tumor in the 4th ventricle which was accompanied by diffuse meningeal dissemination, and metastases were present throughout the peritoneal surface...

Correlation between the neural noise in the thalamus after cerebrovascular disease and computerized tomography. A case report

The case is presented of a 45-year-old man who suffered from a sudden attack of unconsciousness with right hemiplegia and later developed a spastic hemiparesis accompanied by involuntary movement of the right upper limb. CT scan revealed an old putaminal hemorrhage and almost intact thalamus, but neural noise recordings during the stereotactic thalamotomy of this case showed marked decrease of the neural activity in the thalamus suggesting some functional changes.