Granules with broken membranes were isolated from sonicated, purified rat serosal mast cells on a Percoll gradient. When the granules were incubated with [γ³²P]ATP and Mg²⁺ in the absence of exogenous protein kinases and substrates, one major radioactive band was recovered in the 44 K area after SDS/PAG electrophoresis. The phosphorylation reaction with ATP requires Mg²⁺ and 1 mM Mg²⁺ produces the maximal response. The initial reaction is rapid and the maximal response is seen at 30°C. The reaction is enhanced by 0.05 ?? 0.5 μM cyclic AMP and is inhibited by Ca²⁺ (0.45 mM and higher). There is no obvious effect of phosphatidylserine and phorbol ester TPA on the reaction. The 44 K phosphorylated protein is made up of several components ranging in isoelectric point from approximately 7.6 to 6.6. This cyclic AMP-dependent phosphorylating activity in the granules may provide a mechanism by which the granules respond rapidly to cyclic AMP during mediator release.

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The effect of nicardipine on experimental hyperlipemia induced by a 1% cholesterol diet in spontaneously hypertensive rats (SHR) was investigated by the change of hemodynamics and the determination of lipid contents of the serum, liver, heart and aorta. Nicardipine increased liver weight and liver weight per body weight ratio, and it decreased heart and kidney weight significantly. Nicardipine inhibited the increase in blood pressure with cholesterol and normal diets. Nicardipine decreased heart rate in SHR fed the normal diet, and it inhibited the increase in heart rate in SHR fed the cholesterol diet. Serum lipid levels significantly increased with the cholesterol diet. Nicardipine significantly increased cholesterol in high density lipoprotein (HDL-C) and phospholipid in HDL (HDL-PL) with cholesterol and normal diets, and it decreased triglyceride and improved the atherogenic index “(total cholesterol-HDL-C)/HDL-C” with the normal diet. Serum GOT and GPT significantly increased with the cholesterol diet. Nicardipine significantly enhanced an increase in GOT and GPT levels with the cholesterol diet. Nicardipine increased phospholipid content in the liver, triglyceride in the heart, and it decreased total cholesterol in the aorta. A morphologic study showed a fatty liver in SHR fed the cholesterol diet, but nicardipine had no effect on the morphological changes in the liver, heart and aorta. These results suggest that nicardipine may prevent atherosclerotic degeneration by the inhibition of hypertension, increase in serum HDL and decrease in total cholesterol in the aorta.

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Effects of electroacupuncture (EA) on pain threshold and β-endorphin (β-End) contents in plasma, pituitary (Pit), hypothalamus (Hyp) and cerebrospinal fluid (CSF) were studied in nontreated, dexamethasone (Dex) treated and adrenalectomized (Adrex) male SD rats by the use of specific determination of rat β-End (combination of HPLC and RIA). EA increased pain threshold and plasma β-End with no effect on β-End contents in Pit, Hyp and CSF. Dex did not affect control pain threshold, but tended to reduce EA-induced increase in pain threshold (EA-analgesia, EAA) and EA-induced increase in plasma β-End. Adrex increased plasma β-End without change in control pain threshold. Adrex tended to reduce EAA, but a tendency of further increase in plasma β-End was observed after addition of EA. Adrex increased Pit β-End, but no further change in Pit β-End was observed after addition of EA. A positive correlation between plasma β-End and plasma ACTH was observed in nontreated, Dex treated and Adrex rats. No correlation between plasma β-End and potency of EAA was observed in nontreated, Dex treated and Adrex rats. The hind-paw pressure test without EA increased plasma β-End to the same degree as that produced by EA, and it produced no analgesia. These results suggest that Pit β-End may not be mainly involved in the development of EAA.

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The effect of a new sleep inducer, 450191-S, on the hepatic drug-metabolizing enzyme system was examined using rats and compared with those of nitrazepam and phenobarbital. Cytochrome P-450-dependent 7-alkoxycoumarin O-dealkylation activity determined using liver homogenate and isolated microsomes increased after successive oral administrations of 450191-S, and induction of the enzyme system was observed by administration of 150 ?? 200 mg/kg of the drug for at least 3 ?? 5 days. Normal activity was recovered with withdrawal of the drug for 3 ?? 5 days after induction of the hepatic enzyme system. Administration of higher amounts of 450191-S (200 ?? 600 mg/kg/day) for 3 days caused remarkable increases in the O-dealkylase and UDPGA-glucuronyltransferase activities and cytochrome P-450 and b₅ contents. Similar changes in the hepatic enzyme system were observed with administration of nitrazepam (200 ?? 600 mg/kg for 3 days, p.o.) or phenobarbital (10 ?? 40 mg/kg for 3 days, i.p.). We concluded that the inducing activity of 450191-S is almost the same as that of nitrazepam, but weaker than that of phenobarbital. When the hepatic enzyme system was induced by the administration of either 450191-S or phenobarbital, the pentobarbital-induced sleeping time was shortened with increasing doses of the drugs. On the other hand, sleeping time was prolonged by the administration of another type of inducer, β-naphthoflavone. The results suggest that the inductive pattern of 450191-S is similar to that of phenobarbital.

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The transport of a new sleep-inducer, 450191-S, and its metabolites, M-1, M-2, M-A, M-3 and M-4, to the brain was examined by the BUI (Brain Uptake Index) method in rats and by comparing the plasma and the brain concentration of the metabolites in mice. 450191-S was not passed to the brain and M-A was hardly passed, but the permeability of M-1, M-2 and M-3 was as high as that of diazepam. The blood-brain barrier (BBB) permeability of these benzodiazepines correlated with the lipid solubility expressed by the Rm value. After oral administration of 450191-S or M-1 to mice, the common major metabolites, M-1, M-2, M-A, M-3 and M-4, were detected in the plasma. At the dose level of 5.5 μmol/kg, M-A showed the highest plasma concentration among the metabolites, but only a low level in the brain. At an increased dose of 55 μmol/kg, M-2 showed the highest concentration in both the plasma and the brain. These results with mice correlated well with the results of BBB permeability in rats. The brain level of M-4 was almost at the background level in spite of a considerable plasma level. The total brain concentration of pharmacologically active metabolites immediately after administration of M-1 rose much faster and to a higher level than after 450191-S administration. These results may explain the pharmacological character of 450191-S.

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Behavioral and electroencephalographic effects of lormetazepam were investigated in rats, mice and rabbits, in comparison with those of diazepam, nitrazepam and flurazepam. Locomotor activity of mice in an open-field situation was decreased with large doses of lormetazepam and diazepam, while it was increased with nitrazepam and flurazepam. The anticonflict effect of lormetazepam in rats was much more potent than those of diazepam, nitrazepam and flurazepam. In suppressing the muricide of olfactory bulbectomized and raphe lesioned rats, lormetazepam was more potent than diazepam, nitrazepam and flurazepam. Lormetazepam, diazepam and flurazepam prevented both maximal electroshock and pentetrazol convulsions in mice, the effects on' the latter being much more potent than those on the former. Lormetazepam was more potent than diazepam and flurazepam in potentiating thiopental-, ether- and ethanol anesthesia, impairing rotarod performance and in muscle relaxant activity. In conscious rabbits with chronically implanted electrodes, lormetazepam induced a drowsy EEG pattern and suppressed the EEG arousal responses not only to auditory stimulation but also to electrical stimulation of the midbrain reticular formation or hypothalamus. Lormetazepam also inhibited afterdischarges induced by electrical stimulation of the hippocampus and amygdala. These results indicate that lormetazepam has pharmacological properties characteristic of benzodiazepines and that the activity is more potent than those of diazepam, nitrazepam and flurazepam.

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