Search PubMed⌕ Search

Biomedical subjects

M Matsuki

Publications and source records attributed to M Matsuki.

At least 127 records · Page 7Linked to original sources

Dexamethasone suppressibility of plasma pregnenolone or dehydroepiandrosterone in gonadectomized patients.

The 9 AM dexamethasone suppression test was carried out in gonadectomized patients, and plasma pregnenolone or dehydroepiandrosterone (DHA) was radioimmunoassayed following various amounts of dexamethasone administration. Pregnenolone, as well as the plasma ACTH level, was completely suppressed with 1 mg dexamethasone, whereas 4 mg or 8 mg of dexamethasone was needed to induce a complete DHA suppression. These findings suggest that the gonads alone contribute to the poor dexamethasone suppressibility of pregnenolone in normal subjects, and that adrenal DHA secretion might be also regulated by an unidentified factor other than ACTH, which would be suppressed with large doses of dexamethasone.

Adrenocorticotropic Hormone↗

Dishabituation of mesencephalic reticular neurons by anesthetics.

To determine whether neuronal firing is affected by anesthetics, the behavior of neurons in the mesencephalic reticular formation in response to repetitive somatosensory stimulation at 2/sec was studied during wakefulness and during nitrous oxide, halothane, and thiopental anesthesia in the cat. With clinical doses of the three anesthetics there were simultaneous blockades of both initial facilitation (28 of 32) and subsequent habituation (31 of 32) of the evoked responses in a majority of the mesencephalic reticular formation neurons. This dishabituation phenomenon was most prominent with thiopental and least prominent with nitrous oxide. Thus, it is suggested that progressive inactivation of not only the facilitatory process but also the inhibitory process in the neuronal activities of the mesencephalic reticular formation is associated with the so-called "anesthetic state" produced by these three anesthetics.

Anesthetics↗