Effect of amitriptyline or phenobarbital on the activities of the enzymes involved in rat liver

The effect of phenobarbital (PB) or amitriptyline (AMT) on phospholipid metabolism was studied in rat liver. Administration of PB or AMT caused a marked increase in the microsomal phosphatidylcholine (PC) content. In this context, the activities of glycerophosphate acyltransferase (GAT), phosphatidate cytidylyltransferase (PCT), phosphatidate phosphohydrolase (PPH) and choline phosphotransferase (CPT) in the liver were all increased by PB. In contrast, the activities of GAT and PCT were little affected by AMT, while those of PPH and CPT were significantly increased by AMT. These findings suggest that AMT or PB would increase hepatic microsomal PC synthesis through inducing PPH and then CPT.

Effects of perphenazine, chlorpromazine or CoCl2 on the activities of delta-aminolevulinic acid synthetase and heme oxygenase and on the content of hemoprotein in rat liver

Administration of CoCl2 caused a marked decrease of hepatic drug-metabolizing enzymes and the induction of delta-aminolevulinic acid (delta-ALA) synthetase and heme oxygenase. Under the same experimental condition, the inverse relationship between the decrease of hepatic drug-metabolizing enzymes and delta-ALA synthetase activity and the increase of heme oxygenase activity was observed in perphenazine (PPZ)- or chlorpromazine (CPZ)-treated rats. However, the decrease of cytochrome P-450 and aniline hydroxylase by CPZ was later restored or increased over the control level. In addition, CPZ resulted in a marked decrease of total heme content, but this content was not changed by PPZ.

Acute effect of amitriptyline, phenobarbital or cobaltous chloride on delta-aminolevulinic acid synthetase, heme oxygenase and microsomal heme content and drug metabolism in rat liver

Cobaltous chloride (CoCl2) caused very marked decreases of cytochrome P-450, b5 and total heme contents and an increase of heme oxygenase activity. On the contrary, phenobarbital (PB) increased hepatic drug-metabolizing enzymes, but the total heme content remained unchanged. On the other hand, amitriptyline (AMT) caused a marked increase of delta-aminolevulinic acid (delta-ALA) synthetase activity at 12 and 24 hr. In addition, the contents of total heme and cytochrome b5 and the activities of aminopyrine (AM) N-demethylase and aniline (AN) hydroxylase at 24 hr were also increased by AMT, whereas cytochrome P-450 content did not change. This may be explained by the fact that AMT would increase hepatic heme synthesis through the prolonged induction of delta-ALA synthetase, but it may not cause an increase in cytochrome P-450 heme because there are increases in the contents of cytochrome b5 and total heme.

Solubilization and characterization of a ouabain-sensitive protein from transverse tubule membrane-junctional sarcoplasmic reticulum complexes (TTM-JSR) in cat cardiac muscle

A new glycoprotein of 31,500 dalton, which has a high affinity for ouabain, and is independent of (Na+-K+)-ATPase, was solubilized from transverse tubule membrane and junctional sarcoplasmic reticulum complexes (TTM-JSR) of cat cardiac muscle. This protein could be extracted only in small amounts from sarcolemma-plasma membrane (SLM-PL) fragments, suggesting that it indeed originates from the TTM-JSR.

Preparation of the bifidus milk powder

Malt extract and skim milk were used as the culture medium for bifidobacteria. Bifidobacterium longum E194b (ATCC 15707) selected from among four strains grew well in a nitrogen atmosphere regardless of the initial dissolved oxygen level of the culture medium. The optimum temperature range for growth was 34 to 37 degrees C. The viable cell numbers of Bifidobacterium in freeze-dried powder from neutralized bifidus milk were 20 times those found in powder from nonneutralized milk after storage for 30 d at 35 degrees C. The optimum residual water content in the powder for bacterial stability was about 3.5% or less. Bifidus milk powder prepared under these optimum conditions contained at least one billion viable cells even after storage for 30 d at 35 degrees C. The powder must be sealed with material made of aluminium for storage.

Effects of perphenazine, diazepam and nitrazepam on amitriptyline metabolism in rat

Repeated coadministration of amitriptyline (AMT) and perphenazine (PPZ) decreased the AMT-induced increase of hepatic microsomal aminopyrine N-demethylase, aniline hydroxylase, NADPH-cytochrome c reductase and UDP-glucuronyltransferase (UDP-GT) activities in rats. This may be explained by a fact that inhibition of AMT metabolism in hepatic microsomes by PPZ led to increase the non-conjugated formation of AMT and its metabolites in the liver, brain, urine and feces. On the other hand, a slight decrease of drug metabolizing enzyme activity by diazepam (DZP) but not by nitrazepam (NTZ) was enhanced by combined treatment of AMT, whereas the enhancement of UDP-GT activity by DZP or NTZ was suppressed by coadministration of AMT. At the same time there was no clear increase of non-conjugated formation of AMT metabolites in rat urine and feces during combined treatment.

[Analyses of industrial society from ecology--modeling analyses of industrial ecological system]

A macroscopic industrial ecological model has been developed to investigate the effects of changes in industrial structure on social well-being in general and health in particular. The model is composed of the following sectors: industry and employment, environment and pollution, and population and health care. The model was calibrated using available data of the past 60 years for Japan. The simulation study was conducted with the time span of 1920 to 2000. The results indicated that the gradual shift, in the industrial structure of Japan, would improve the level of living standards resulting in enhanced health service capability and lower death rate although increasing adult disease rates in the aged society. Also the rapid future growths of service industry and information and communication were observed.

Cost-benefit analysis of medicinal treatment for gastric ulcers. Long-term model including healing and recurrence

Cost-benefit analysis (CBA) and cost-effectiveness analysis (CEA) are increasingly being used in medical practice and in health policy making. The choice among alternative treatments, the aim of a more efficient use of limited resources and the wider goal of cost containment, are so many reasons for CBA and CEA. This paper addresses the rather unexplored field of long-term cost-benefit analysis. Gastric ulcer, which is a recurrent disease is taken as a case study. Mathematical modelling is used for situation analysis of alternative long-term intervention strategies. The use of recurrence in the model makes the results of earlier CBA's based on the healing of a single episode, open to question. The paper holds important lessons for both the theoretical aspects of CBA and for its utilization in health policy formulation.

Subcellular distribution of 3H-digitoxin and its metabolites in the hearts of the cats with a hypersensitivity to the drug

To clarify the cause of hypersensitivity to digitoxin, an experiment was carried out with cats. The most potent hypersensitivity to digitoxin has been observed 48 hr after the injection of a loading dose. However, 1 hr after this injection, the cats failed to show the hypersensitivity. One, 24 and 48 hr after the injection of 3H-digitoxin, the contents of digitoxin and its metabolites in subcellular fractions of hearts were measured. Digitoxin contents in microsomal fractions 48 hr after the injection only slightly decreased. while those in mitochondrial and nuclear fractions markedly decreased as compared with the check at 1 hr. An increase of sodium ions and a decrease of potassium ions in the hearts were seen 48 hr after the injection. These facts may be related to the cause of hypersensitivity.

Studies on the Indonesian Antiaris toxicaria sap

The present research is on a milky sap obtained from the Antiaris toxicaria tree (Moraceae) which is called Upas or Ipoh in Indonesia. The crude sap was administered to anesthetized rats, and changes in electrocardiogram (ECG) and systemic blood pressure was observed. Biologically and pharmacologically active components were extracted from the crude sap by means of water-acetone solution. Based on the strength of chemical qualitative detection tests of the sap extract (SE), cardiac glycosides are supposed to be the main components. The SE inhibited the Na+-, K+-ATPase (EC 3.6.1.3) which was partially purified from guinea pig heart muscle. When the SE and, concurrently, authentic ouabain were applied to isolated frog heart muscles, the fall of twitch tension was observed after the increased tension on mechanograms. These facts suggest that the main components of the milky sap are cardiac glycosides, and glycosides affect Na+, K+-ATPase activity of muscle membrane and heart muscle contraction.

Ouabain potentiation and Ca release from sarcoplasmic reticulum in cardiac and skeletal muscle cells

In this article, we describe a possible mechanism of ouabain potentiation in heart based on the following findings in cardiac and skeletal muscles of various species. (1) In heart ventricle muscles of frog and guinea pig, the ouabain potentiation is produced without an effect on Ca influx. In both frog and cat heart ventricle muscles, ouabain potentiates the rapid cooling contracture with or without caffeine in a Ca-deprived medium. It follows, therefore, that the ouabain potentiation is produced by an "intracellular" mechanism. (2) In crab single muscle fibers, contractile responses such as twitch, potassium-induced contracture, caffeine-induced contracture, and water-induced contracture are remarkably potentiated if ouabain is present within the fibers by microinjection, whereas the situation is reversed if the drug is given extracellularly. (3) The ouabain potentiated the Ca release from fragmented sarcoplasmic reticulum (FSR) isolated from cat, guinea pig, and frog heart and from skeletal muscles as a result of the procedures used, such as changing the ionic environment. (4) In frog, cat, and guinea pig heart ventricle muscles, a reduction of contractility as a result of pretreatment with urea--Ringer's was completely cancelled by ouabain almost without influencing the membrane depolarization. Based on these findings and others, the deduction was made that the positive inotropic effect of cardiac glycosides on the heart is brought about by potentiation of contraction - Ca release from the intracellular store sites, namely the sarcoplasmic reticulum.

Ouabain potentiation of rapid cooling contracture of caffeinized cardiac muscles in calcium deprived medium

To obtain further evidence concerning the intracellular action of ouabain, we observed the effect of this compound on contractures evoked by rapid cooling in the presence of caffeine (rapid cooling caffeine contracture; RCCC), in cardiac muscles under conditions of a Ca deprived medium. The experiments were carried out at 20 degrees C using cat papillary muscles and frog ventricle strips, with the exception of cooling (2 degrees C). The muscles were first immersed in normal solution, electrically driven, then immersed in 1 mM EDTA solution for 6 min. The strips were then immersed for 10 min in a caffeine solution prepared by eluting a no-Ca solution containing 50 mM caffeine through Dowex A-1, Ca-chelating resin. Finally, the caffeine solution was exchanged with fresh caffeine solution of 2 degrees C to evoke to RCCC. Ouabain (1 X 10(-7)--1 X 10(-5) M) markedly potentiated RCCC. An ouabain-induced increase of RCCC did not appear in the resting strips unless the tissues were electrically stimulated. 3H-ouabain occupied a considerable cellular space (0.55) at the appearance of the ouabain potentiation of RCCC (14C-inulin space; 0.20). The appearance of the ouabain potentiation of RCCC was independent of changes in 22Na, Ca2+ and ATP contents in the strips. A possible mechanism of the potentiating effect of ouabain on contraction is discussed.

Effects of alpha blockers on blood pressure and on the Ca-contracture of cat aortic strips

To further clarify the hypotensive mechanism of adrenergic alpha blockers, effects of several alpha blockers on systemic blood pressure and on Ca-contracture of isolated, cat aortic strips were studied. For this purpose, the effects of known adrenergic alpha blockers, phentolamine, phenoxybenzamine, and a newly synthesized adrenergic alpha blocker (2-(N-(n-Butyloyl)homopiperazine-N'-yl)-4-amino-6,7-dimethoxy quinazoline; E-643) were compared with those of nitroglycerin and verapamil. Systemic blood pressure was decreased by administration (2 x 10(-8) moles/kg i.v.) of all drugs except phenoxybenzamine. The order of maximal fall of diastolic blood pressure after the injection was; nitroglycerin greater than E-643 greater than phentolamine greater than verapamil greater than phenoxybenzamine. Although "adrenaline reversal" was observed after 2 x 10(-7) moles/kg of phenoxybenzamine, i.e. a 10-fold increase in the dose of phenoxybenzamine, there was no decrease in systemic blood pressure with this dose. All these drugs in a concentration of 2 x 10(-6) M inhibited the Ca-contracture (phasic and tonic) of the depolarized aortic strips. The order of inhibition of phasic and tonic contracture was: nitroglycerin greater than E-643, verapamil greater than phentolamine greater than phenoxybenzamine. The pA2 values for phentolamine and E-643 in antagonizing contractions produced by noradrenaline of cat aortic strips were 7.8 and 8.2, respectively. Hypotensive effects of these drugs (except phenoxybenzamine), parallel the inhibitory effects on the Ca-contracture of the aortic strips. These results suggest that alpha blockers such as phentolamine and E-643 exert a systemic hypotensive effect not through their alpha blocking action but by an inhibitory action on the contractile Ca-mechanism.

Microinjection of ouabain into crab single muscle fibers and the mechanism of ouabain potentiation

In order to clarify the mechanism of the potentiating effect of ouabain on contraction, a study was made of the effect of microinjection of 1.5 μL of ouabain on contractile responses and 22Na efflux, using single muscle fibers of crab (i–iii), and the results obtained were compared with observations (iv) on frog hearts. (i) Microinjected ouabain was dissolved with distilled water or isosmotic potassium glutamate solution. In both cases, ouabain remarkably potentiated both contraction evoked electrically and contractures induced by potassium or caffeine. (ii) Microinjected ouabain increased only the size of a contracture (water-induced contracture) which appeared immediately after the microinjection of distilled water into the fibers, reserpine increased only the duration of the contracture, and caffeine increased both the size and the duration of the contracture. (iii) In crab fibers equilibrated previously with 22Na-containing crab saline solution, extracellularly applied ouabain inhibited both contraction and 22Na efflux from the fibers whereas intracellularly applied ouabain markedly enhanced contraction without a change in the 22Na efflux, (iv) In frog hearts, extracellularly applied ouabain showed a positive inotropic action which was accompanied by occupation of a considerable cellular space by [3H]ouabain and not by a decrease in 22Na efflux. From these results, we concluded that for the appearance of ouabain potentiation the drug must get into the cell and that the potentiation was elicited independent of ouabain-induced inhibition of Na-K-ATPase activity in the muscle. Furthermore, a possible mechanism of the potentiating effect of ouabain on contraction was discussed.