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Biomedical subjects

M Satoh

Publications and source records attributed to M Satoh.

At least 1,063 records · Page 59Linked to original sources
PubMed1985

Met-enkephalin and morphine but not dynorphin inhibit noxious stimuli-induced release of substance P from rabbit dorsal horn in situ.

The effects of locally applied opioids on the release of immunoreactive Substance P (iSP), induced by mechanical stimuli, from the dorsal horn of the rabbit in situ, were investigated. Morphine and met-enkephalin (met-enk), but not dynorphin A (1-17) (DYN), in a concentration of 10 microM, significantly inhibited the evoked release. These inhibitory effects of morphine and met-enkephalin were antagonized by the local application of naloxone (10 microM) to the dorsal horn. These results suggest that the inhibition of the release of Substance P induced by noxious mechanical stimuli may be mediated by mu and delta, but not by kappa opioid receptors.

Animals↗
PubMed1985

Intracerebroventricular administration of angiotensin II attenuates morphine-induced analgesia in mice.

The central effect of angiotensin II on the analgesic action of morphine in mice was investigated using the tail-pinch and hot plate tests. Angiotensin II (0.1-10 pmol), given intracerebroventricularly (i.c.v.), had no effect on the nociceptive sensitivity but did produce a dose-dependent attenuation of the morphine-induced analgesia. A specific angiotensin II antagonist, Saralasin (1 pmol), which in itself had no analgesic effect, significantly potentiated the morphine-induced analgesia. These results suggest that angiotensin II probably plays the physiological role of an anti-opioid substance in pain-modulating systems in the brain.

Analgesia↗
PubMed1985

Sites of analgesic actions of kyotorphin and D-kyotorphin in the central nervous system of rats.

Kyotorphin(KTP) and its analog D-kyotorphin(D-KTP) which is resistant to enzyme degradation produced dose-dependent analgesic effects in the tail-pinch test when applied locally to the periaqueductal gray (PAG), nucleus reticularis paragigantocellularis(NRPG) and lumbosacral subarachnoid space(LSS) near the spinal dorsal horn in rts. ED50 values of both dipeptides at the PAG, NRPG and LSS were: 59.0, 105 and 52.6 micrograms/rat for KTP, and 6.2, 8.8 and 10.6 micrograms/rat for D-KTP, respectively. Pretreatment with naloxone(1 mg/kg s.c.) significantly inhibited the analgesic effects of KTP and D-KTP at the PAG and LSS but not at the NRPG. Simultaneous administration of bestatin (2.5 or 50 micrograms) with KTP enhanced the analgesic effect of KTP in the PAG and LSS but not in the NRPG. These findings suggest that the analgesic actions of KTP and D-KTP result from two different mechanisms, 1)enkephgalin-releasing mechanism in the PAG and spinal dorsal horn, and 2)a mechanism without involvement of enkephalin-releasing actions in the NRPG.

Analgesics↗
PubMed1985

How is kyotorphin (Tyr-Arg) generated in the brain?

Kyotorphin (Tyr-Arg) was rapidly degraded in the brain homogenates and purified membrane-bound aminopeptidase from monkey brains. The degradation of kyotorphin by these preparations was effectively inhibited by bestatin. When brain homogenates or slices were incubated with bestatin, kyotorphin was accumulated time-dependently in a rate of 1.0 or 2.1 pmol/mg protein/hr, respectively. The bestatin-induced kyotorphin accumulation was inhibited by leupeptin, p-chloromercuribenzoate, but not phenylmethylsulfonylfluoride or diisopropylphosphate. The kyotorphin accumulation was concentrated in the P2 (crude mitochondrial) fraction, particularly in the particulate or synaptosomal fraction. These findings suggest that kyotorphin may be generated in vitro from precursor proteins by membrane-bound, leupeptin-sensitive "kyotorphin converting enzymes" in close vicinity to membrane-bound aminopeptidase which rapidly degrades kyotorphin generated.

Animals↗
PubMed1985

[Effect of pirprofen on bradykinin-induced flexor reflexes of rat and rabbit hindlimbs].

The analgesic effects of pirprofen on bradykinin-induced flexor reflexes in rats and rabbits were investigated in comparison with those of indomethacin and ibuprofen by oral administrations. The bradykinin-induced flexor reflexes in rats were suppressed by pirprofen at 10 mg/kg-200 mg/kg, the effect reaching plateau at over 30 mg/kg. Suppression at the dose of 200 mg/kg was 56%. A similar dose-dependent curve was obtained for ibuprofen at 30 mg/kg-300 300 mg/kg. On the other hand, indomethacin exerted dose-dependent inhibition at 1 mg/kg-10 mg/kg without a tendency to reach the plateau effect within this dose range. Suppression at the dose of 10 mg/kg was 83%. The ED50 values of pirprofen, indomethacin and ibuprofen were 68 mg/kg, 3.3 mg/kg and 94 mg/kg, respectively. On the bradykinin-induced flexor reflexes in rabbits, pirprofen showed 60% suppression at the dose of 10 mg/kg, of which the effects were roughly equivalent to those of indomethacin and ibuprofen at the same dosage. These results indicate that there is a species difference concerning the three drug activities on bradykinin-induced flexor reflexes between the rat and the rabbit.

Animals↗
PubMed1985

Sudden nocturnal death in young males from ventricular flutter.

Two young males who had no organic heart disease died unexpectedly during the night. In one patient, the monitor ECG showed a sinoatrial block and the electrophysiologic study revealed a sinoatrial conduction time at the upper limit of normal and a prolonged PA interval. The surface ECG showed left axis deviation. Ventricular ectopic beats were confined to the night when he died from ventricular flutter. The ECG of the other patient was normal except for the change in QRS configuration found when the preceding RR interval was prolonged, suggesting a phase 4 block in intraventricular conduction. He was completely free from arrhythmia except for the ventricular ectopic beats which developed around 9:00 p.m. and the ventricular flutter following an R-on-T type ventricular ectopic beat which resulted in death during the night. The autopsy showed no organic heart disease. ST elevation suggestive of acute ischemia was not found and the QT intervals were normal in both cases. No electrolyte imbalances were found. These 2 cases can be diagnosed as pokkuri disease which is well known in Japan. The victims are exclusively young males who have no apparent diseases to which death can be attributed.

Adult↗
PubMed1985

A simple catheter technique for production of AV block.

Atrioventricular (AV) block was produced in animals for experimental purposes by use of a newly devised cannula. It has bipolar electrodes; one electrode on the needle tip and the other 5.0 mm proximally from the tip. Otherwise, the cannula was electrically completely insulated. The cannula was inserted from the right external jugular vein and advanced close to the AV ring. While His bundle electrogram was obtained with the electrodes, the AV node was accessed. The injection site was determined as the point where His bundle electrogram can be well recorded and the atrial electrogram is close to or larger than the ventricular electrogram in amplitude. Xylocain solution, 0.2 to 0.4 ml, was injected with the syringe attached on the other end of the cannula. Transient AV block occurred when the needle tip was properly positioned. Then, 0.2 ml to 0.4 ml of anhydrous alcohol was added to make permanent a AV block. A possible application of this technique was implicated.

Animals↗
PubMed1985

Bitemporal compression injury caused by static loading mechanism. Report of two cases.

The authors report two cases of bitemporal compression injury caused by a static loading mechanism. These head injuries resulted from gradual bitemporal compression of the head. Plain skull films showed multiple skull fractures, and carotid angiography revealed internal carotid artery obstruction at the base of the skull. Neurological examination disclosed a slight disturbance of consciousness, hemiparesis, multiple cranial nerve injuries, and Horner's syndrome. In comparison with impact head injury, the energy from this type of trauma tends to be transmitted to the foramina and hiati of the middle cranial fossa and results in multiple injuries to the cranial nerves, sympathetic nerves, and blood vessels.

Adult↗
PubMed1985

The histogenesis of the gonad in rat embryos.

Gonadogenesis was investigated using Wistar rat embryos at 12-14 days after fertilisation. In indifferent gonads, a mesonephric tubule which bifurcates from the mesonephric duct at the upper end of the gonadal anlage ramifies into six to eight branches, the distal portions of which are contiguous, in contact with, or in close proximity to, the coelomic epithelium of the gonadal ridge. After the primordial germ cells reach the gonadal ridge, the overlying epithelium proliferates and clear cells appear in the distal portion of each mesonephric tubule, proliferating and forming cord-like structures. The primordial germ cells appear to enter these cell cords by an amoeboid type of movement. The basal lamina covering the cell cord partially disappears near the germ cells. The germ cells within the cord migrate toward the proximal portion of the cell cord and proliferate in great profusion. From the present observations, it can be concluded that the gonad is mainly formed of clear cell cords originating in mesonephric tubules into which germ cells have entered. The original mesenchymal cells and blood vessels form the interstitial tissue of the gonad. The rete testis and rete ovarii are of mesonephric tubule origin.

Animals↗
PubMed1985

Reduced hepatic clearance of propranolol induced by chronic carbon tetrachloride treatment in rats.

Effect of liver injury induced by chronic treatment with carbon tetrachloride for 1 to 4 months on hepatic clearance of propranolol was investigated in male Wistar rats. Plasma propranolol level after i.v. and p.o. dosing (1.0 mg/kg) was always higher in the rats which were treated for 2 and 4 months than in control (sham-injected) rats. The chronic treatment reduced hepatic clearance of propranolol significantly, yielding only approximately 30 to 50% of the control clearance value. Distribution volume of this drug was also significantly reduced by the chronic treatment but seemed to be less sensitive to the treatment than the hepatic clearance. Accordingly, the elimination rate constant was decreased slightly in the rats treated longer than 2 months. The chronic treatment for 2 and 4 months also reduced intrinsic hepatic clearance substantially. The hepatic clearance estimated for both these control and chronically treated rats was significantly dependent on the liver blood flow. Furthermore, propranolol was eliminated much more slowly in the injured liver of the rat which was treated for 2 or 4 months than in the control liver when perfused in in vitro technique. It is, therefore, suggested that the metabolic dysfunction induced by chronic treatment with carbon tetrachloride may be directly related to substantial changes in anatomical arrangement of the hepatic circulation (portasystemic shunting), which may be due to a fibrosis of the tissue.

Animals↗
PubMed1985

Clinicopathologic investigation of ovarian endometriosis: a comparative study of cystic and non-cystic types.

This clinicopathologic study involved 129 patients with ovarian endometriosis. All the lesions from the patients were classified macroscopically into two types being either cystic or non-cystic. The results are as follows. Endometriotic lesions were bilateral in 58 cases and unilateral in 71 cases. The average age of the patients was 38.8 and gravidity 1.8, with 43.1% of them being infertilite. In 12.2, 45.4 and 84.6% of them, irregular menstruation, hypermenorrhea, and dysmenorrhea were recorded, respectively. Regarding complicated lesions, 49 patients had fibroid, 33 uterine adenomyosis, and 13 rectocervical endometriosis. Of the 129 cases, 61.3% were regarded as of the cystic type, 30.2% as of the non-cystic type, and 8.5% as of the cystic/non-cystic type. The average ages were 35.5 and 41.6 years for cystic and non-cystic types, respectively. The incidence of each type of complicated lesion mentioned above was greater in the non-cystic type than that in the cystic type. The pathogenetic investigation suggested that cystic endometriosis in the ovary might mainly be ascribed to the endometrioid metaplasia of the celomic epithelium and that non-cystic endometriosis might occasionally originate from metastasis or implantation of endometrial tissues. In addition to this, the lesions which were histologically diagnosed as endometriosis might sometimes include obsolete follicle cysts undergoing luteinization.

Adolescent↗
PubMed1985

[A case of multiple cavernous hemangiomas of the lung].

A case of multiple cavernous hemangiomas of the lung is presented. A 61-year-old woman was suffering from mitral stenosis and insufficiency. On the chest roentgenogram, multiple tumor shadows were revealed at all the lobes of the lung. She had been followed up for about 10 years under the diagnosis of the metastatic carcinoma of the lung. But no tumor lesion had been found at any other organs. Throughout this period, the tumor shadows had not changed in size or number. She died of congestive heart failure, and an autopsy was performed. Histologically, the tumors were diagnosed as cavernous hemangiomas and differentiated from arteriovenous fistula or sclerosing hemangioma.

Female↗