Basal levels of pituitary ACTH and plasma corticosterone after complete or frontal cuts around medial basal hypothalamus.

Plasma corticosterone level and corticotropin (ACTH) content of the anterior pituitary (AP) were measured after various cuts around the medial basal hypothalamus (MBH). Seven to eight days after placing a complete cut around MBH there was no change in plasma corticosterone or ACTH content of AP; the slight rise in ACTH concentration was offset by the decreased weight of AP. Twenty eight days after a frontal cut there was no change in plasma corticosterone and in bioactive or immunoreactive ACTH concentration of AP.

Corticoliberin (CRF) activity of the rat neurohypophysis.

Corticoliberin (CRF) activity of the rat stalk-median eminence region (SME) and neural lobe of the pituitary (NL) was tested in vitro using cultured cells of anterior pituitary. The activity of NL was found to be more than 50% lower than that of SME. The parallelism of dose-response curves suggests that corticotropin releasing substances originating from NL and SME may be qualitatively identical.

[Insurance and preventive medicine].

Not only do insurance companies have to pay in case of death, injuries or disease, they are also concerned with their prevention. This is particularly true for the "Swiss National Accident Insurance Fund" (Caisse nationale suisse d'assurance en cas d'accidents--(CNA): for them the prevention of work related accidents and occupational diseases is required by law. Preventive activities in this area are very promising.

Catecholamine concentration of various brain nuclei of the rat as affected by ACTH and corticosterone.

The acute effect of ACTH and corticosterone on catecholamine concentration of individual brain nuclei has been examined. ACTH significantly increased the noradrenaline (NA) content in the locus coeruleus, and decreased it in the ventromedial and arcuate nuclei. No change was observed after ACTH in the dopamine (DA) concentrations of the mentioned areas and in the catecholamine level of the mamillary body, hippocampus, medial habenular nucleus and of the pituitary.

Evaluation of a radioimmunoassay for plasma adrenocorticotrophin.

A radioimmunoassay for plasma ACTH has been described and evaluated. Rabbit antiserum produced by immunization with [Asp25, Ala26, Gly27,]-alphah-corticotrophin-(1--28)-octacosa-peptide (a sequence analogue of alphah1--28-ACTH) bovine gamma globulin conjugate was used. The antiserum is specific for the NH2-terminal portion of the ACTH molecule and cross-reactivity of human, porcine and rat ACTH in the system has been demonstrated.

Possible role of gamma-aminobutyric acid synthesis in the mechanism of dexamethasone feedback action.

Specific inhibition of glutamic acid decarboxylase (GAD, EC 4.1.1.

The influence of nitrous oxide anaesthetic on middle-ear fluid.

Nitrous oxide anaesthesia invades the middle-ear cavity, resulting in a positive pressure within this cavity. It has been suggested that the pressure may be sufficient to force open the Eustachian tube and evacuate fluid from the middle ear. This study examined the possible influence of nitrous oxide on middle-ear fluid.

ACTH release after tuberal electrical stimulation in rats with various cuts around the medial basal hypothalamus.

After the combined treatment with dexamethasone, morphine and pentobarbitone, the electrical stimulation in the rat tuber cinereum induces a rise in plasma corticosterone (CS) level, probably by direct stimulation of the corticoliberin-producing neural elements and the consecutive ACTH release. We have attempted to locate these corticoliberin-containing neural elements by electrical stimulation in rats with various surgical cuts (deafferentations) around the medial basal hypothalamus (MBH). Seven to eight days after the complete circumsection of the MBH, the electrical stimulation of the isolated region did not affect plasma CS level.

Preparation and assessment of antisera to ACTH.

Antisera to ACTH were produced in rabbits injected repeatedly at multiple intradermal sites with synthetic [Asp25, Ala26, Gly27]alphah-corticotropin-(1-28)-octacosapeptide-bovine gamma globulin conjugate (octacosapeptide is a sequence analogue of alphah1-28-ACTH). Antibodies to extracted human or porcine ACTH were detected in all of the sera 1 month after immunization. A considerable proportion of the antisera obtained from a single final bleeding 5 months after the primary immunization were suitable for sensitive radioimmunoassay.

Catecholamine turnover measurement and ACTH-induced short-term changes of catecholamine levels in individual brain nuclei.

The effect of acute ACTH treatment on catecholamine content of various brain nuclei was followed by radioenzymatic assay. The hormonal treatment employed affected catecholamine levels only in some hypothalamic nuclei and in the locus coeruleus. Some effects could be detected as rapidly as 10 min after the injection of the hormone.

Esophageal infarction complicating spontaneous rupture of the thoracic aorta.

An 81-year-old man suffered a spontaneous rupture of the thoracic aorta through an atheromatous plaque, leading to total dysphagia and eventual esophageal infarction.

Competitive protein binding assay of oestradiol-17 beta and oestrone using uterine cytosol prepared from HCG-treated rabbits.

Uterine cytosol was prepared from rabbits after treatment with human chorionic gonadotrophin (HCG) and used for the determination of oestradiol-17 beta and oestrone by competitive protein binding (CPB) assay. The so obtained uterine cytosol gave higher percentage of binding and proved to be more stable when stored at --20 degrees C than cytosol obtained from the pregnant uterus.

Microspectrophotometry of mitochondrial cytochrome P-450 in single adrenal cells.

The cytochrome P-450 is known to be a key enzymic component in steroid hydroxylation. Biochemically it is localized in adrenal cells, both in the mitochondrial and in the microsomal fractions. Owing to its characteristic light absorptivity, attempts were made at its localization and measurement in a microspectrophotometric system.

Hypothalamic region and pathways responsible for adrenocortical response to surgical stress in rats.

Surgical stress produced no increase in the plasma corticosterone level in rats with complete deafferentation of the medial basal hypothalamus (MBH). 30 min after surgical stress, the adrenocortical response depended on the integrity of a well-circumscribed region of the hypothalamus: the lateral-basal region of the retroachiasmatic area (RCAL) that lies not more than 0.5 mm caudally from the optic chiasma and is about 0.

Corticotroph cells in primary cultures of rat adenohypophysis: a light and electron microscopic immunocytochemical study.

Monolayer cultures of trypsin-dispersed cells of the rat adenohypophysis were grown for 5 to 54 days. ACTH was localized by immunocytochemistry using an antiserum to synthetic ACTH1-28 prepared in rabbit and sheep anti-goat immunoglobulin coupled with peroxidase. ACTH content of the culture medium was measured by radioimmunoassay.

The effects of cholinomimetic drugs and atropine on ACTH release.

Acetylcholine (1 and 50 mug), carbamylcholine (1 and 10 mug), and oxotremorine (10 mug) were infused into the 3rd ventricle of rats with deafferented medial basal hypothalamus (MBH); infusions failed to stimulate ACTH release as shown by the plasma corticosterone level. Implants of an atropine-fluorescein mixture (200-250 mug) inhibited the stress-induced rise of plasma corticosterone only when dye from the implant stained large portions of the median eminence and the basal hypothalamus. Atropine implants near the electrodes inhibited the rise in plasma corticosterone usually produced by electrical stimulation in the anterior hypothalamus.

Effect of cortexolone on the feedback action of dexamethasone.

Cortexolone in a dose of 1 mg/100 g body wt., administered to rats prior to dexamethasone, prevented dexamethasone from suppressing stress-induced ACTH-release without interfering with the effect of dexamethasone on the resting plasma corticosterone level.

[Ultrastructure and hormone secretion of a tissue culture from an adrenal gland tumor simulating Cushing's syndrome].

Tissue cultures of a surgically removed adrenocortical tumour causing Cushing's syndrome, and tissue cultures from the attached, tumour-free adrenal were studied. There were two cell types characteristic of tumour tissue. The cell type occurring most frequently had pronounced hypertrophied agranular endoplasmic reticulum.

Changes in the fine structure and function of a hormone-secreting adrenocortical tumour investigated in tissue culture.

Tissue cultures of a surgically removed adrenocortical tumour causing Cushing's syndrome, and tissue cultures from the attached, tumour-free adrenal were studied. There were two cell types characteristic of tumour tissue. The cell type occurring most frequently had pronounced hypertrophied agranular endoplasmic reticulum.