Synthesis and biological activity of new 3-hydroxy-3-methylglutaryl-CoA synthase inhibitors: 2-oxetanones with a side chain mimicking the extended structure of 1233A

Structural analogs of 1233A, a microbial metabolite inhibiting 3-hydroxy-3- methylglutaryl coenzyme A (HMG-CoA) synthase, were designed and synthesized. The 2-oxetanone moiety was left intact. All analogs prepared were tested for inhibition of HMG-CoA synthase activity and sterol synthesis in mouse liver and for effect on serum triglyceride levels. Of these analogs, trans-4-[2-[3-(7-carboxy-2- naphthyl)phenyl]ethyl]-3-hydroxymethyl-2-oxetanone (4a) showed the highest inhibitory activity in vitro, and also had in vivo inhibitory activity without causing any increase in triglyceride level.

Accessory cell ability of Langerhans cells for superantigen is resistant to ultraviolet-B light

We examined the effects of ultraviolet-B (UVB) irradiation on the accessory cell ability of Langerhans cells (LC) to induce a T-cell response to a superantigen, staphylococcal enterotoxin B (SEB). The ability of LC-enriched epidermal cells (LC-EC) to evoke a T-cell response to SEB was retained at the doses of UVB (up to 40 mJ/cm2) that profoundly affected the antigen-presenting function of LC-EC for a hapten, trinitrophenyl (TNP), and a protein antigen, conalbumin. Thus, the LC accessory function for superantigens is more resistant to UVB irradiation than that for ordinary antigens. This UVB resistance is presumably due to no requirement of antigen processing for superantigens as chemically fixed or chloroquine-treated LC-EC still retained their ability to induce T-cell responses to SEB. Higher doses of UVB (more than 60 mJ/cm2) reduced the accessory cell ability of LC-EC for SEB up to 50% of control. The addition of monoclonal antibodies against adhesion molecules between LC and T cells to the culture resulted in a substantial suppression of the T-cell response to SEB induced by nonirradiated LC-EC, while the UVB-irradiated LC-EC-induced T-cell response was not significantly blocked with these monoclonal antibodies. This suggested that the reduction of LC ability for superantigen by high doses of UVB is at least partly due to the impairment of adhesion molecules on LC by UVB irradiation.

Synthesis and biological activity of new 3-hydroxy-3-methylglutaryl-CoA synthase inhibitors: 2-oxetanones with a meta-substituent on the benzene ring in the side chain

Isosteric side chain analogs of 3a were synthesized and tested for inhibitory activities towards 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) synthase and upon cholesterol production in Hep G2 cells and in mouse liver. It became clear that the lipophilic substituent on the aromatic ring and the terminal hydrophilic group in the side chain were important in the enhancement of activity. 4-[2-(3-n-Hexyloxyphenyl)ethyl]-3-hydroxy-methyl-2-oxetanone (5a) showed equivalent inhibitory activity in vivo to that of 1233A.

Lymphomatoid papulosis associated with acquired ichthyosis

We describe a 64-year-old man with lymphomatoid papulosis associated with acquired ichthyosis. The papulonodular lesions were composed of large atypical lymphocytes positive for CD3, CD4, and Ki-1. The ichthyosiform eruption also occurred on the extremities and had the histologic features of ichthyosis vulgaris. Although monoclonality of infiltrating cells could not be demonstrated, acquired ichthyosis appears to be induced in patients with lymphomatoid papulosis by the same pathomechanism underlying other lymphoproliferative diseases.

Collagen framework of the volar plate of human proximal interphalangeal joint

The functional roles of the three-dimensional fibrillar ultrastructure of the proximal interphalangeal joint volar plates of human fingers were studied by light microscopy and scanning electron microscopy. The results revealed that the volar plate consists of three layers of fibers. The first layer forms an intracavity wall with two parts, the proximal "membranous portion", and the distal "meniscoid protrusion" that is separated from the middle phalangeal base by a "recess". The second layer contains the "check ligament", which lies parallel to the fibers of the tendon, anchors tightly into the middle phalangeal base, and protects the joint from hyperextension. The third layer connects to the fibers from the accessory ligament and ligamentous tendon sheath of the A3 pulley, perpendicularly crosses the fibers of the tendon, becomes the periosteum of the middle phalangeal base, and functions as a hanging support for the volar plate and as a gliding floor for the flexor tendon.

Synthesis and biological activity of new 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) synthase inhibitors: 2-oxetanones with a side chain mimicking the folded structure of 1233A

To mimic the folded side chain conformation of 1233A (1), which is a 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) synthase inhibitor, 1233A analogs with aromatic rings in the side chain were synthesized. The 2-oxetanone moiety was kept intact. Among 1233A and its synthetic analogs, trans-3-hydroxymethyl-4-[2-(7-methoxycarbonyl-1-naphthyl)ethyl]-2-oxe tanone (23) showed the highest HMG-CoA synthase inhibitory activity in vitro. The structure-activity relationship at the side chain is discussed.

Clinicopathological analysis of de Quervain's disease

Excised extensor retinacula of the first compartment and tenosynovium from 35 patients (6 men and 29 women) with de Quervain's disease were examined by light and electron microscopy to investigate the pathogenic mechanism. The patients, aged from 22-78 years, averaging 50 years, comprised the study group. Two hundred and thirty-two specimens from cadavers of 95 men and 75 women were macroscopically examined as the control. In the study group, the extensor retinaculum and tenosynovium were macroscopically thickened, and were histologically classified into 4 groups based on presence or absence of septum, and the location of retinacular thickening. Morphologically, the thickening of the tenosynovium and retinaculum was due to fibrosis in every layer, although fibroses were seen mainly in the middle layer. The ratios of proliferation of fibroblasts, myxoid changes and/or hyaline degeneration, and vascular proliferation were varied between layers. Minimal round cell infiltration was found in the retinaculum as well as in the tenosynovium. The results also indicate that the Iwahara-Nozue test can be used to accurately predict relatively greater thickening of the retinaculum on the extensor pollicis brevis side. Based on clinicopathological analyses, it appears that de Quervain's disease is induced not only by extrinsic factors such as superficial friction but also by intrinsic factors.

Bopindolol and its metabolite 18-502 attenuate regional myocardial acidosis during partial occlusion of the coronary artery in dogs

The effects of bopindolol (a new, nonselective beta-adrenoceptor antagonist) and its active metabolite, 18-502, on the regional myocardial pH during coronary occlusion were studied. Mongrel dogs were anesthetized with pentobarbital and the thorax was opened to expose the heart. The left anterior descending coronary artery (LAD) was incompletely (or partially) occluded so that the LAD flow could be reduced to about one third of the original flow. Regional myocardial pH of the LAD area was continuously measured by a tissue pH monitor. Drugs were injected intravenously 30 minutes after LAD partial occlusion. The myocardial pH in the LAD area decreased in response to LAD partial occlusion (from 7.3-7.4 to 6.72-6.92), and the low pH value was sustained for 60 minutes after LAD occlusion. Atenolol (1 mg/kg) decreased heart rate markedly and attenuated the regional myocardial acidosis induced by LAD partial occlusion. Bopindolol (1 mg/kg) decreased heart rate and 18-502 (0.5 mg/kg) decreased heart rate and blood pressure. Both drugs attenuated to a similar degree the decrease of regional myocardial pH induced by LAD occlusion. In the dog whose heart rate was maintained constant, however, bopindolol (1 mg/kg) did not attenuate the decrease of regional myocardial pH induced by LAD occlusion. These results suggest that both bopindolol and 18-502 attenuate the ischemia-induced regional acidosis of the myocardium as does atenolol, and, hence, have an anti-ischemic action. The beneficial action of bopindolol on ischemia-induced myocardial acidosis is possibly due to a decrease of heart rate, which corresponds to a saving of energy in the myocardial cells.

Epidermal antigens and complement-binding anti-intercellular antibodies in pemphigus vegetans, Hallopeau type

The serum of a 34-year-old woman with the Hallopeau type of pemphigus vegetans (PVg) contained antibodies against a 130-kDa polypeptide in human epidermal lysates, as revealed by Western blot analysis. The serum strongly fixed complement in vitro, and the PVg lesional skin contained a predominance of complement-fixing IgG2 and IgG4. Although the antigens reactive with sera from PVg and pemphigus vulgaris were the same, strong fixation of complement by PVg antibodies, due to the presence of complement-dependent IgG subclasses, and subsequent in situ activation of complement, might explain the marked infiltration of neutrophils and eosinophils in PVg.

Posterior interosseous nerve paralysis related to focal radial nerve constriction secondary to vasculitis

A case of posterior interosseous nerve paralysis is reported with discussion of some characteristics that appear to distinguish it from entrapment neuropathy and neuralgic amyotrophy. The surgical implications are also discussed. More than ten similar cases have been reported, but the pathogenesis of this condition is still controversial. The patient presented with posterior interosseous nerve paralysis related to focal radial nerve constriction secondary to vasculitis in the perineurium. The constriction site was resected and the radial nerve was sutured. The patient recovered completely after 8 months.

Protective effect of crataegus extract on the cardiac mechanical dysfunction in isolated perfused working rat heart

The effect of the water-soluble fraction of Crataegus (Crataegus extract) on the cardiac mechanical and metabolic function was studied in the isolated, perfused working rat heart during ischemia and reperfusion. Ischemia (15 min) was produced by removing afterload pressure, and reperfusion (20 min) was produced by returning it to the original pressure. In the control (no drug) heart, ischemia decreased mechanical function to the lowest level, which did not recover even after the end of reperfusion. Crataegus extract (0.01 or 0.05%) was applied to the heart from 5 min before ischemia through the first 10 min after reperfusion. With the high concentration of Crataegus extract (0.05%) the mechanical function recovered during reperfusion incompletely without increasing coronary flow, but the low concentration of Crataegus extract (0.01%) did not. In the heart treated with the high concentration of Crataegus extract, the reperfusion-induced recovery of the energy metabolism was accelerated, and the level of lactate during ischemia was lower than that in the control heart, although the myocardial levels of free fatty acids during ischemia and reperfusion were not greatly affected. These results demonstrate that Crataegus extract (0.05%) has a cardioprotective effect on the ischemic-reperfused heart, and that the cardioprotective effect is not accompanied by an increase in coronary flow.

Absorption mechanism of 1,3-bis(2-ethoxycarbonylchromon-5-yloxy)-2-((S)-lysyloxy )propane dihydrochloride (N-556), a prodrug for the oral delivery of disodium cromoglycate

To clarify the absorption mechanism of 1,3-bis(2-ethoxycarbonylchromon-5-yloxy)-2-((S)-lysyloxy+ ++)propane dihydrochloride (N-556), a prodrug for the oral delivery of disodium cromoglycate (DSCG), a study was made using rats. N-556 gave the highest plasma level of DSCG following its injection into the loop at the upper part of the small intestine. N-556 was stable in acidic washings of gastric contents, but rapidly hydrolyzed to M1 with twin ethyl residues on DSCG in the washings of the small intestinal contents. N-556 and M1 were hydrolyzed to DSCG via M2 having a mono ethyl residue in the homogenate of the small intestinal mucosa. The oral absorption of M1 following its administration in 50% (v/v) propylene glycol solution was essentially the same as that of N-556. That of M1 administered in aqueous suspension was low. After the oral administration of N-556, a small amount of M2 and a trace of M3 having L-lysyl residue were detected in the portal plasma, but no hydrolytic intermediate except DSCG could be found in the general plasma. The major absorption mechanism of N-556 may thus be concluded as follows: N-556 given orally is transferred to the small intestine in essentially intact form. N-556 is then rapidly diffused to an aqueous layer on the surface of the mucosal membrane and hydrolyzed to M1. The resultant M1 is transported to the mucosal membrane and hydrolyzed to DSCG via M2. DSCG generated in the mucosal membrane is used for general circulation through the portal blood and liver.(ABSTRACT TRUNCATED AT 250 WORDS)

Superoxide radical scavenging activity of phenolic compounds

1. Superoxide radicals (O2-.) were generated from a hypoxanthin-xanthin oxidase (HPX-XOD) reaction system and detected by the electron spin resonance (ESR) spin-trapping technique. 2. The inhibitory effect on O2-. generation occurred in the order: superoxide dismutase (SOD) > L-ascorbic acid > eugenol > guaiacol > phenol. 3. And the second-order rate constants between O2-. and samples were: SOD 1.7 x 10(9)/M/S, L-ascorbic acid 3.4 x 10(5)/M/S, eugenol 8.3 x 10(3)/M/S, guaiacol 2.5 x 10(3)/M/S and phenol 5.8 x 10(2)/M/S. 4. It was clarified that the phenolic compounds have O2-. scavenging activity.

Characteristics of 1,3-bis-(2-ethoxycarbonylchromon-5-yloxy)-2-((S)- lysyloxy)propane dihydrochloride (N-556), a prodrug for the oral delivery of disodium cromoglycate, in absorption and excretion in rats and rabbits

The absorption and excretion of 1,3-bis-(2-ethoxycarbonylchromon-5-yloxy)-2- ((S)-lysyloxy)propane dihydrochloride (N-556), which is a prodrug for the oral delivery of disodium cromoglycate (DSCG), were studied in rats and rabbits. In both animal species, the plasma concentration of DSCG after oral administration of N-556 peaked within 1.0 h, and thereafter declined with a half-life of about 1.2 h in rats and rabbits. The area under the plasma DSCG level versus time curve (AUC) increased in proportion to the dose of N-556 in both animals. The bioavailability of N-556 as calculated from AUC was about 6% in rats and 40% in rabbits, whereas that of DSCG was only 0.1% in rats and 2.5% in rabbits. About 2% and 15% of the dose were respectively excreted as DSCG in the urine and bile after the oral administration of N-556 in rats. The ratio of biliary excretion to urinary excretion (B/U) after the oral administration of N-556 was about twice that after the intravenous injection of DSCG. In rabbits, the urinary and biliary excretions of DSCG after oral administration of N-556 were about 25% and 5%, respectively. The B/U ratio after the oral administration of N-556 in rabbits was similar to that after intravenous administration of DSCG. The difference in the systemic bioavailability of N-556 between rats and rabbits thus appears to be due to a first-pass effect, in addition to a difference in the absorption rate.

Effects of phenylalaninol on centrally induced gastric acid secretion

The effects of phenylalaninol (D-isomer) on gastric acid secretion and gastric ulcer were studied in rats. The compound reduced the gastric acid secretion stimulated by intracisternal thyrotropin releasing hormone and intravenous 2-deoxy-D-glucose, but not that stimulated by subcutaneous carbachol or histamine. Phenylalaninol prevented stress- and indomethacin-induced gastric ulcers. We conclude that phenylalaninol inhibits ulcer formation mainly by central inhibition of gastric acid secretion.

Adult T-cell leukemia with regression of erythroderma and simultaneous emergence of leukemia

A patient with smoldering adult T-cell leukemia had refractory erythroderma. Concomitant with the development of acute leukemia, the cutaneous lesions disappeared spontaneously. This suggests an extensive release of tumor cells from the skin to the blood.

Importance of hydrolysis of amino acid moiety in water-soluble prodrugs of disodium cromoglycate for increased oral bioavailability

The relationship between physicochemical properties and oral absorption was investigated in prodrugs for the oral delivery of disodium cromoglycate (DSCG). To improve the lipophilicity of DSCG, various lipophilic moieties were introduced into the twin carboxyl groups. However, this did not lead to improved oral absorption in rabbits because of loss of water solubility, in spite of improved lipophilicity. Water-soluble prodrugs, in which an amino acid was introduced into a hydroxy group by ester linkage in addition to ethyl residues at twin carboxyl groups of DSCG, were synthesized and examined for oral absorption in rabbits and rats. The oral absorption of these prodrugs was affected by the species of amino acids introduced as a water-soluble moiety. Therefore, we examined the relation between the oral absorption of water-soluble prodrugs and the hydrolysis rate of the amino acid moiety. A good linear correlation was obtained between the oral absorption and the hydrolysis rate constant catalyzed by digestive enzymes, trypsin or alpha-chymotrypsin. It was thus concluded that the amino acid moiety of water-soluble prodrugs must be rapidly hydrolyzed to a permeable lipophilic prodrug still possessing the ethyl moiety at twin carboxyl groups in the small intestinal tract for good oral absorption.

[A comparative study of cefepime for bacterial pneumonia]

The efficacy, safety and usefulness of cefepime (CFPM), a new cephem antibiotic, in bacterial pneumonia, were evaluated in a comparative study against ceftazidime (CAZ). Each drug was administered by intravenous drip infusion at a dose of 1.0 g (nominal potency) twice daily for 14 days, and the following results were obtained. 1. A total of 183 cases were enrolled in this study. Efficacy rates ("good" or better responses) as evaluated by the subcommittee were 90.3% (65/72) in the CFPM group and 94.0% (63/67) in the CAZ group, with no significant difference between the 2 groups. 2. Efficacy rates ("good" or better responses), as evaluated by attending physicians, (in the same bacterial pneumonia cases which were subjected to evaluation by the subcommittee) were 87.5% (63/72) in the CFPM group and 89.6% (60/67) in the CAZ group, with no significant difference between the 2 groups. 3. Bacteriologically, eradication rates were 96.9% (31/32) in the CFPM group and 96.7% (29/30) in the CAZ group with no significant difference between the 2 groups. 4. The incidence of side effects was 5.9% (5/85) in the CFPM group and 4.8% (4/84) in the CAZ group, with no significant difference between the 2 groups. No significant difference was also found between the 2 groups in the incidence of abnormal laboratory findings; 28.4% (23/81) of the case in the CFPM group and 34.1% (28/82) in the CAZ group. 5. As for overall usefulness of the drug in bacterial pneumonia cases, utility rates ("useful" or better evaluations) as evaluated by the subcommittee were 88.9% (64/72) in the CFPM group and 92.5% (62/67) in the CAZ group. The rates as evaluated by investigators (in cases judged as evaluable by the subcommittee) were 87.5% (63/72) and 85.1% (57/67), respectively. There were no significant differences between the 2 groups. These results indicated that CFPM is very useful for the treatment of bacterial pneumonia.

Synthesis of 1233A analogs and their inhibitory activity against hydroxymethylglutaryl coenzyme A synthase

Simple and efficient syntheses of 1233A analogs were developed and the inhibitory activity of the analogs against hydroxymethylglutaryl coenzyme A (HMG-CoA) synthase was determined. Study of the structure-activity relationships revealed that not only the geometry in beta-lactone moiety but also the length of the carbon side chain is important for inhibitory activity against HMG-CoA synthase.

Impairment of the myocardial ultrastructure and changes of the cytoskeleton in dilated cardiomyopathy

This study was designed to determine the morphological correlate of chronic heart failure. Myocardial tissue from eight patients undergoing transplantation surgery because of end-stage dilated cardiomyopathy was investigated by electron microscopy and immunocytochemistry using monoclonal antibodies against elements of the cytoskeleton: desmin, tubulin, vinculin, and vimentin. The tissue showed hypertrophy, atrophy of myocytes, and an increased amount of fibrosis. Ultrastructural changes consisted of enlargement and varying shape of nuclei, numerous very small mitochondria, proliferation of T tubules, and accumulation of lipid droplets and glycogen. The most obvious ultrastructural alteration was the decrease of myofilaments, ranging from rarefication to complete absence of sarcomeres in cells filled with unspecified cytoplasm. Immunocytochemistry showed that desmin was localized at the Z lines. In diseased myocardium, the amount of desmin was increased, but it was disorderly arranged. Tubulin formed a fine network throughout the myocytes and was significantly increased in cardiomyopathic hearts. Vinculin, a protein closely associated with the cytoskeleton, occurred not only at the sarcolemma and the intercalated disc but also within the myocardial cells. Ultrastructural changes and alterations of the cytoskeleton were severe in about one third of all cells. About one third of all cells showed moderately severe changes, and the remaining cells were normal. Vimentin was present in the interstitial cells and was increased in relation to the increase of fibrosis. We conclude that the increase of fibrosis, the degeneration of hypertrophied myocardial cells, and the alterations of the cytoskeleton are the morphological correlates of reduced myocardial function in chronic heart failure.

Production of antikeratin autoantibodies by hybrid spleen cells of naive mice

The mechanism of the occurrence of natural antikeratin antibodies in human sera was studied using hybrid spleen cells obtained from experimentally naive or from immunized mice. Antikeratin antibodies were detected by enzyme-linked immunosorbent assay (ELISA) in 5.9-9.5% of the culture supernatants of fused spleen cells taken from naive mice. When mice were immunized with keratins, the number of supernatants containing antikeratin antibodies was increased to eight out of 51 (15.7%). When immunized with non-keratin materials such as activated human T cells, adult T-cell leukaemia cell lysates, and human T-cell lymphotropic virus type-I (HTLV-I), 16.7-20.8% of the supernatants were found to contain antikeratin antibodies by ELISA. The antikeratin antibodies in the supernatants showed cytoplasmic staining of keratinocytes in human as well as mouse skin by indirect immunofluorescence. The antibodies reacted with extracted human epidermal keratins by dot-blot and Western blot analysis. Most antikeratin antibodies in the supernatants did not show cross-reactivity with exogenous antigens used for immunization and vimentin-type intermediate-sized filaments. These findings demonstrate that B cells producing antikeratin antibodies are common in naive mice, and produce various types of antikeratin antibodies following specific activation with epidermal keratins and non-specific immunological stimuli.

Phase-only computer-generated hologram produced by an ion-exchange technique

We have produced a highly efficient phase-only hologram, in which the refractive index of the substrate is modified by using an ion-exchange method. This binary phase-only hologram is produced using a conventional binary hologram as a mask for the ion exchange. A simplified theory of the phase-only hologram is presented along with a description of the fabrication method and the experimental test results.

Propranolol inhibits accumulation of non-esterified fatty acids in the ischemic dog heart

The effects of propranolol and d-propranolol on the accumulation of non-esterified fatty acids (NEFA) induced by complete occlusion of the left anterior descending coronary artery (LAD) for 90 min, were investigated in dogs anesthetized with pentobarbital. The myocardial levels of eight NEFA (lauric, myristic, palmitic, palmitoleic, stearic, oleic, linoleic and arachidonic acids) were determined after fluorescent labelling of the NEFA with 9-anthryldiazomethane. LAD occlusion increased the myocardial levels of NEFA, especially those of arachidonic and palmitoleic acids; arachidonic acid increased by 3.5 times and palmitoleic acid by 2.9 times. Pretreatment with propranolol (1 mg/kg) inhibited almost completely the accumulation of NEFA induced by occlusion of the LAD, whereas pretreatment with d-propranolol (1 mg/kg) did not inhibit the accumulation of NEFA, although it tended to inhibit the accumulation of palmitoleic, stearic and arachidonic acids. These results suggest that the inhibitory action of propranolol on the accumulation of NEFA in the myocardium during ischemia is mainly due to its antagonistic effect at beta-adrenoceptors and probably partly due to its effect as a local anesthetic.

In vitro and in vivo antibacterial activity of KY-109, a new orally active cephalosporin

The in vitro and in vivo antimicrobial potencies of KY-109, a pro-drug of KY-087, were compared with those of amoxicillin, cephalexin (CEX), and cefaclor (CCL). The following results were obtained. KY-087, which is the active form of KY-109, had broad antimicrobial spectrum against Gram-positive and Gram-negative organisms, but showed low antimicrobial activity against Enterobacter sp., Serratia, and Pseudomonas sp. The antimicrobial activities of KY-087 against clinically isolated Gram-positive organisms were superior to those of CEX and CCL. The antimicrobial activities of KY-087 against Gram-negative organisms, such as Enterobacter sp., Serratia, and Pseudomonas sp., were less active. KY-087 showed dose-related bactericidal activity against Staphylococcus aureus and Escherichia coli. The therapeutic efficacy of KY-109 against experimental intraperitoneal infections caused by Gram-positive and Gram-negative organisms in mice was comparable to that of CEX but inferior to that of CCL. In experimental granuloma pouch models in rats and kidney infection in rabbits, therapeutic efficacy of KY-109 was either comparable or superior to that of CEX and CCL.

Rapid changes in myofibrillar proteins after reperfusion of ischemic myocardium in dogs

The effect of reperfusion on cardiac myofibrillar proteins in the irreversibly injured ischemic myocardium was studied in dogs. Ischemia of the myocardium was produced by complete occlusion of the left anterior descending coronary artery for 90 min (the group of 90I). Occlusion of the coronary artery was then released (reperfusion) for 0.5 min (the group of 90I + 0.5R), 5 min (the group of 90I + 5R), or 20 min (the group of 90I + 20R). In control dogs, the coronary artery was not occluded (the group of no ischemia). Myofibrils (Mfp) were prepared from the myocardium (with centrifugation) in each of the groups, and subjected to electrophoretic analysis in terms of myofibrillar proteins. The yield of Mfs in the groups of 90I, 90I + 0.5R, 90I + 5R, and 90I + 20R was lower than that in the group of no ischemia. There were no marked differences, however, in the electrophoretic pattern of Mfp among the five groups. These results suggest that myofibrils are broken down during reperfusion after ischemia. Therefore, supernatant solution after the first stage of homogenization during the course of preparation of myofibrils (mfs) was also examined. There were many unidentified bands in Mfs, being assumed to be originated from myofibrillar proteins, in the groups of both 90I + 0.5R and 90I + 5R, although these bands were not observed in the group of 90I. These results indicate that degradation of myofibrillar proteins occurs rapidly after reperfusion of the irreversibly injured myocardium. It is uncertain, however, whether reperfusion has a detrimental effect on the reversibly injured myocardium, too.

Accumulation of nonesterified fatty acids in the dog myocardium during coronary artery occlusion determined by a method using 9-anthryldiazomethane

The levels of nonesterified fatty acids (NEFA) in the myocardium during ischemia were determined by a simple method, which requires neither previous separation with thin-layer chromatography nor heating. After being extracted with Folch's solution, NEFA were subjected to fluorescent labeling with 9-anthryldiazomethane at room temperature, separation with high-pressure liquid chromatography, and then detection by a flow-through fluorometer. Calibration and validation studies revealed that this method was satisfactory. The left anterior descending coronary artery was completely occluded for 90 min in dogs anesthetized with pentobarbital. In the nonischemic myocardium, the levels of lauric, myristic, palmitic, palmitoleic, stearic, oleic, linoleic, and arachidonic acids were 5.31, 15.85, 47.06, 2.59, 23.92, 37.90, 38.69, and 3.99 nmol/g wet tissue, respectively, and those in the ischemic myocardium 5.67, 22.16, 75.94, 6.65, 42.67, 61.75, 70.06, and 13.39 nmol/g wet tissue, respectively, the total NEFA in the former being 175.3 and that in the latter 298.3 nmol/g wet tissue. The increase in myocardial NEFA during ischemia was significant except for lauric and myristic acids, and the increase in arachidonic acid was the greatest. The ratio of the level of arachidonic acid in the ischemic myocardium to that in the nonischemic myocardium was 335.6%.