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Biomedical subjects

Y Deguchi

Publications and source records attributed to Y Deguchi.

At least 19 recordsLinked to original sources
PubMed2000

Efficacy of influenza vaccine in the elderly: reduction in risks of mortality and morbidity during an influenza A (H3N2) epidemic for the elderly in nursing homes.

The effect of influenza vaccination on the occurrence and severity of influenza virus infection in elderly nursing home residents was studied during an influenza A (H3N2) epidemic in Japan. Of 22,462 individuals living in 301 welfare nursing homes, 10,739 received inactivated (subunit) influenza vaccine. Through the period November 1998 to March 1999, there were 950 cases of influenza infection diagnosed clinically, with virus isolation and/or serology. There were statistically significantly fewer cases of influenza, hospital admissions due to severe infection, and deaths due to influenza in the vaccinated cohort compared with the unvaccinated controls. No serious adverse reactions to vaccination were recorded. Thus influenza vaccination is safe and effective in this population, and should be an integral part of the routine care of persons aged 65 years and over residing in nursing homes.

Aged↗
PubMed2000

The attitude of Japanese family caregivers toward the elderly with dementia.

This research examined family caregivers' attitudes toward their elderly relatives living with dementia. A convenience sample of fifty-nine Japanese caregivers was used. Caregiver attitudes were investigated multi-dimensionally (negative attitude, attitude of acceptance, and attitude of active interaction) using a questionnaire developed specifically for this study. The dimensions did not correlate with one another but were associated with different caregiver/elderly characteristics: i.e., negative attitude with short stay use, length of time caregivers and elderly relatives were living together and problem behaviors; attitude of acceptance with sleeping pill use and the type of relationship; and attitude of active interaction with dementia diagnosis. The results have implications for nurses in facilitating constructive caregiver attitudes.

Aged↗
PubMed2000

Brain distribution of 6-mercaptopurine is regulated by the efflux transport system in the blood-brain barrier.

6-mercaptopurine (6-MP) has been used clinically for 40 years to maintain remission in patients with acute lymphoblastic leukemia (ALL). However, central nervous system (CNS) relapses frequently occur in patients with ALL who continuously receive anticancer drugs, including 6-MP, during remission maintenance therapy. The cause of such CNS relapse is not well understood. One possible reason may involve the restricted distribution of 6-MP in the brain. This study, therefore, investigates the blood-brain barrier (BBB) transport which largely regulates 6-MP distribution in the brain using a quantitative microdialysis technique and centers on the efflux transport of 6-MP across the BBB. The brain tissue, cerebrospinal fluid (CSF), or hippocampal interstitial fluid (ISF) concentration of 6-MP was very low compared with the unbound plasma concentration, suggesting that 6-MP distribution in the brain is highly restricted. Kinetic analyses of this BBB transport showed that the efflux clearance from brain ISF to plasma across the BBB (CLout) is approximately 20-times greater than the influx clearance from plasma to brain (CLin). The CLout was significantly reduced by 1mM N-ethylmaleimide (NEM), a sulfhydryl-modifying agent, suggesting the participation of transport protein in the efflux of 6-MP across the BBB. In addition, efflux transport was inhibited by an intracerebral infusion of probenecid (1.5 mM), p-aminohippuric acid (PAH, 3.0 mM), benzoate (3.6 mM), or salicylate (3.7 mM) administered through a microdialysis probe, but neither choline (0.8 mM) nor tetraethylammonium (TEA, 0.7 mM) had any effect. These data suggest that the restricted 6-MP brain distribution may be ascribed to efficient efflux from the brain, possibly via both the organic anion transport system, shared with probenecid and PAH, and the monocarboxylic acid transport system, shared with benzoate and salicylate.

Animals↗
PubMed2000

In vivo specific binding characteristics and pharmacokinetics of a 1,4-dihydropyridine calcium channel antagonist in the senescent mouse brain.

PURPOSE: To characterize the in vivo specific binding and pharmacokinetics of a 1,4-dihydropyridine (DHP) calcium channel antagonist, PN 200-110, in the senescent brain, using senescence-accelerated prone mice (SAMP8) and senescence-resistant mice (SAMR1). METHODS: Blood, brain, and heart samples were taken periodically from SAMR1 and SAMP8 following intravenous injection of (+)-[3H]PN 200-110, and the concentration of (+)-[3H]PN 200-110 in the plasma and tissues was determined. In addition, the in vivo specific binding of (+)-[3H]PN 200-110 in the brains of SAMRI and SAMP8 was measured periodically after intravenous injection of the radioligand. RESULTS: There was very little significant difference between SAMR1 and SAMP8 in terms of the half-life (t(1/2)), total body clearance (CL(tot)), steady-state volume of distribution (Vd(ss)). and AUC for the plasma concentration of (+)-[3H]PN 200-110 after intravenous injection of the radioligand. The brain concentration (AUCbrain) for (+)-[3H]PN 200-110 and the brain/plasma AUC ratio (AUCbrain/AUCplasma) were significantly lower in SAMP8 than in SAMR1, and the heart concentration (AUCheart) and the heart/plasma AUC ratio (AUCheart/AUCplasma) were similar in both strains. Also, the brain/plasma unbound AUC ratio (AUCbrain/AUCplasma-free) for (+)-[3H]PN 200-110 was significantly lower in SAMP8 than in SAMRI. The in vivo specific binding (AUCspecific binding, maximal number of binding sites: Bmax) of (+)-[3H]PN 200-110 was significantly lower in brain particulate fractions of SAMP8 than SAMR1. CONCLUSIONS: The concentration and in vivo specific binding of (+)-[3H]PN 200-110 was significantly reduced in the senescent brain. The simultaneous analysis of the concentrations of centrally acting drugs and the in vivo specific binding in the brain in relation to their pharmacokinetics may be valuable in evaluating their CNS effects.

Aging↗
PubMed2000

Blood-brain barrier transport of 125I-labeled basic fibroblast growth factor.

PURPOSE: This study was carried out to examine the blood-brain barrier (BBB) transport of human basic fibroblast growth factor (bFGF) and investigate its mechanism. METHODS: The BBB transport of 125I-bFGF was measured by several in vivo methods including intravenous administration, in situ internal carotid artery perfusion, and intracerebral microinjection. The in vitro binding of 125I-bFGF was characterized using freshly prepared bovine brain capillaries. RESULTS: The distribution volume of 125I-bFGF in the postvascular supernatant increased with the perfusion time, and exceeded the space occupied by the brain microvasculature and its trichloroacetic acid (TCA) precipitability was more than 90%. 125I-bFGF avidly bound to isolated bovine brain capillaries with a Bmax of 206 +/- 48 pmol/mg protein, and a Kd of 36.5 +/- 15.7 nM. This binding was significantly inhibited by unlabeled bFGF and heparin in a concentration-dependent manner. The cationic peptides, protamine and poly-L-lysine (each 300 microM), produced over 85% inhibition of 125I-bFGF binding to brain capillaries. Furthermore, glycosaminoglycans with a sulfate residue, chondroitin sulfate B and C (each 10 microg/mL) also inhibited the binding of 125I-bFGF The in vivo transcytosis of 125I-bFGF from the luminal side to the brain was also inhibited by the presence of heparin (10 microg/mL) and poly-L-lysine (300 microM), whereas neither hyaruronic acid (10 microg/mL) nor insulin (10 microM) had any effect. In addition to these results, the brain efflux index method was used to confirm that the transcytosis of 125I-bFGF from brain to blood across the BBB was negligible. CONCLUSIONS: These results suggest that 125I-bFGF is transported across the BBB, possibly by an adsorptive-mediated transcytosis mechanism that is triggered by binding to negatively charged species on the luminal membrane surface of the brain microvasculature, such as heparan sulfate proteoglycans.

Animals↗
PubMed2000

Attenuation of KATP channel-opener induced shortening of repolarization time by alpha 1-adrenoceptor antagonist during ischemia in canine heart.

The purpose of the study was to determine whether a new KATP channel opener, Y 26763 (Y), can influence the electrophysiological properties in the ischemic myocardium as well as to determine whether the blunting effect of the alpha 1-adrenoceptor antagonist bunazosin (BN) on an ischemia-induced shortening of repolarization time can be related to the KATP channel activity. The anterior descending branch of the left coronary artery was ligated four times for 5 minutes, separated by 15 minutes of reperfusion (stages 1-4) to test the dose-dependent effect of drugs on repolarization. Dogs received either vehicle (n = 9), Y (0.4, 2.0, and 4.0 micrograms/kg at stages 2, 3, and 4, respectively, with 0.4 microgram/kg/min drip infusion at each of stages 2-4, n = 7), BN (0.1 mg at each of stages 2-4, n = 8), or a combination of these two drugs (BN + Y, the same dose of BN and Y in groups BN and Y, respectively, n = 9). Drugs were administered into the left atrium. The monophasic action potential (MAP) and regional electrograms were recorded. The MAP90 and the duration of the slow deflections (DSD) of the regional electrogram were used as markers of repolarization. The Vmax of the MAP and the rapid deflections (DRD) of the regional electrogram were used as markers of conduction. Y augmented an ischemia-induced shortening of MAP90 and DSD in proportion to an increase in the dose given and the plasma concentration (P < .05-.01), especially at the epicardial site. BN and BN + Y blunted the ischemia-related shortening of MAP90 and DSD, causing a reduction in repolarization time dispersion between the ischemic and normal zones. There were no significant changes in the Vmax or DRD in the ischemic zone between periods before and after an increase in each drug dose in the four groups. None of the seven dogs developed ventricular tachycardia (VT)/ventricular fibrillation (VF) in the Y group, whereas two of the eight dogs in the BN group, three of the nine dogs in the BN + Y group, and three of the nine dogs in the control group developed VT/VF. These results suggest that the alpha 1-adrenergic blocker bunazosin blunts the shortening effect of KATP channel activator on repolarization time, and that the KATP channel opener Y may be antiarrhythmic, although the repolarization time dispersion during myocardial ischemia is increased.

ATP-Binding Cassette Transporters↗
PubMed2000

Physical and personality traits of preschool children in Fuzhou, China: only child vs sibling.

Concern about the healthy growth and development of an only child has been voiced since the 1970s, when the Chinese government launched the only child policy. In this study, the physical and personality traits of rural Chinese preschool only-children (onlies) whose age ranged from 3 to 6 years old were evaluated. The sample included 197 onlies and 367 children with siblings who came from seven kindergartens in rural areas in Fuzhou, Fujian province. The results showed no statistically significant differences in height, mass or BMI between the onlies and siblings. Regarding the personality traits, the significant difference was that the onlies exhibited more somatic complaints, however, the data didn't indicate any other undesirable personality traits for the onlies. These results suggest that Chinese preschool children grow normally with or without siblings.

Body Height↗
PubMed2000

[Follow-up study related to raising low-birth-weight infants relationship among physical growth, mental development and child-rearing anxiety].

OBJECTIVE: In order to clarify relationship among physical growth, mental development of low-birth-weight (LBW) infants and child-rearing anxiety of mothers, a follow-up study was accomplished for LBW cases from birth to three years of age in a regional group. METHODS: A self-administered questionnaire survey was conducted for mothers whose premature infants were born from April 1992 through March 1993 and whose existence was confirmed from April 1995 through March 1996 in Fukui prefecture. A control group was selected from mature infants whose gestation was 37 weeks or more, who were born in the same year and in the same region. The questionnaire was focused on fetal and child growth, as well as child-rearing anxiety. RESULTS: Of the subjects, while including only 6% very LBW infants, the percentage of full-term LBW infants was 55.3% and that of pre-term LBW infants was 44.7%. In the former group, the mean birth weight (MBW) was 2,319 g, the percentage of females was 63.3%, firstborn children was 59.2%, and light-for-dates (LFD) infants due to intrauterine growth retardation 76.9%. In the latter group, the MBW was 1,983 g, the percentage of females was 52.9%, that of firstborn children was 44.5%, and LFD infants was 14.3%. The growth of the LBW infants through the age of three fell into the same category of growth as the upper portion (1,250-1,499 g) of the very LBW infants rather than that of the mature infants. While the growth of appropriate-for-dates (AFD) infants at full-term were normal, that of LFD infants and pre-term infants was insufficient, and the percentage of those demonstrating catch-up of mature infants was less than 80%. The group of pre-term infants was retarded in the gross motor skills, but not language understanding and pronunciation of two-word sentences. The child-rearing anxiety in mothers who delivered pre-term infants was extremely severe after child birth. As the child grew older, however, the feeling of uneasiness was reduced. Mothers who were delivered of full-term LBW infants did not exhibit any fluctuation in child-rearing anxiety during the first three years. CONCLUSION: Fetal size affects growth progress of children. The prognosis of LBW infants is not satisfactory and mothers who deliver full-term LBW infants continue to worry about their child's growth.

Anxiety↗
PubMed1999

High serum coenzyme Q10, positively correlated with age, selenium and cholesterol, in Inuit of Greenland. A pilot study.

Greenlanders (Eskimos) have low prevalence of ischaemic heart disease, partly explained by a lower extent of atherosclerosis and a low n-6/n-3 ratio of polyunsaturated fatty acids. As atherosclerosis is also a result of oxidative stress, the total antioxidative readiness could have a substantial impact. From a health survey we chose the subpopulation from the most remote area, where the traditional Greenlandic diet with high intake of sea mammals and fish predominates. The mean (SD) of S-CoQ10 in males was 1.495 (0.529) nmol/ml and 1.421 (0.629) nmol/ml in females, significantly higher (p < 0.001) compared to a Danish population. In a linear multiple regression model the S-CoQ10 level is significantly positively associated with age and S-selenium in males, and S-total cholesterol in females. The high level of CoQ10 in Greenlanders probably reflects diet, since no bioaccumulation takes place, and it could probably be a substantial part of the antioxidative defense.

Adult↗
PubMed1999

Acute health problems among the people engaged in the cleanup of the Nakhodka oil spill.

To determine if the Nakhodka oil spill and subsequent cleanup efforts had any health effects on the residents along the oil-contaminated coast, we investigated the health status of Anto residents who resided nearest to the coast where the bow ran aground. Two hundred eighty-two men and women involved in the cleanup activities between January 7 and January 20 were interviewed and examined by public health nurses to determine whether they suffered physical symptoms after exposure to the oil spill. Urine examinations for hydrocarbon toxicological markers were performed on 97 residents. The average number of days worked on cleanup activities was 4.7 days for men and 4.3 for women. Seventeen percent of the subjects had worked on cleanup activities for more than 10 days. Protective equipment was used against direct exposure to oil during the cleanup jobs and consisted of gloves used by almost 100% of the subjects and masks used by 87.1% of women and by only 35.4% of men. Glasses were worn by less than 30% of the subjects. Many symptoms emerged after the beginning of cleanup activities. The principal symptoms included low back pain and leg pain, headache, and symptoms of eyes and throat. Among the subjects undergoing urine tests, only three people showed a higher level of hippuric acid, although they returned to normal in the second examination. Accordingly, the exposure to the oil and the subsequent cleanup efforts were suggested to inflict acute health problems on local residents.

Acute Disease↗
PubMed1999

Brain receptor binding characteristics and pharmacokinetics of JTP-2942, a novel thyrotropin-releasing hormone (TRH) analogue.

JTP-2942 competed with [3H]-Me-TRH for the binding sites in rat brain in vitro, and its inhibitory effect was approximately 17 times less potent than TRH, as shown by Ki values of 673 and 39.7 nM, respectively. Both JTP-2942 and TRH significantly increased apparent dissociation constant (Kd values) for brain [3H]-Me-TRH binding. Intravenous injection of JTP-2942 (0.3-3 mg/kg) and TRH (3 and 10 mg/kg) produced a significant reduction of [3H]-Me-TRH binding sites (Bmax values) in rat brain. Although the decrease by TRH was maximal 10 min after the injection and declined rapidly with time, the decrease by JTP-2942 (1 and 3 mg/kg) tended to be maximal at 30 min later and it lasted until 120 min. The intravenous injection of JTP-2942 was at least 3 times more potent than that of TRH in decreasing Bmax values for brain [3H]-Me-TRH binding. Plasma concentration of JTP-2942 (0.3-3 mg/kg) after intravenous injection in rats rose with the increase of dose, and it peaked immediately after the injection, thereafter decreasing with t1/2 of 19.3-29.9 min. It is concluded that JTP-2942, compared to TRH, may exert fairly potent and sustained occupation of brain TRH receptors under in vivo condition. Thus, JTP-2942 could be clinically useful for the treatment of CNS disorders.

Animals↗
PubMed1999

Comparative study on pharmacokinetics and in vivo alpha1-adrenoceptor binding of [3H]tamsulosin and [3H]prazosin in rats.

The plasma concentration, total radioactivity and in vivo alpha1-adrenoceptor binding in rat tissues after intravenous (i.v.) injection of [3H]tamsulosin were measured and they were compared with those obtained after the injection of [3H]prazosin. The plasma concentration of [3H]tamsulosin was consistently higher than that of [3H]prazosin, with 1.4 times greater areas under the curve (AUC(0-infinity)) of plasma concentration. As there was a significantly lower value of apparent volume of central compartment (Vd(c)) and distribution volume at steady state (Vd(ss)) for [3H]tamsulosin than [3H]prazosin with little difference in elimination rate constant (beta), the higher concentration of [3H]tamsulosin in plasma might be associated mainly with the smaller volume of distribution. The ratio of total radioactivity in tissues to the plasma unbound concentration of [3H]tamsulosin after i.v. injection of the ligand was consistently lower than that of [3H]prazosin. These observations suggest that [3H]tamsulosin is distributed in rat tissues in a more limited manner than [3H]prazosin. A significantly lower level of in vivo specific binding of [3H]tamsulosin than [3H]prazosin was observed in the spleen, heart and liver. Further, the apparent dissociation constant (Kd) and maximal number of binding sites (Bmax) for in vivo specific [3H]tamsulosin binding were considerably lower than those for [3H]prazosin binding. Therefore, these findings suggest that [3H]tamsulosin labels preferentially a subpopulation of the alpha1-adrenoceptor sites in rat tissues labeled by [3H]prazosin. In conclusion, the present study has shown that there is a significant difference in the pharmacokinetics and in vivo alpha1-adrenoceptor binding characteristics between tamsulosin and prazosin.

Adrenergic alpha-Antagonists↗
PubMed1999

In vivo measurement by [3H]Tamsulosin of alpha1 adrenoceptors in rat tissues in relation to the pharmacokinetics.

The present study was undertaken to simultaneously measure alpha1 adrenoceptors in rat tissues by [3H]tamsulosin in vivo. In vivo specific [3H]tamsulosin binding was observed in the prostate, vas deferens, aorta, submaxillary gland, spleen, heart, lung, and kidney after i.v. injection of the ligand but not in the cerebral cortex and liver. Specific [3H]tamsulosin binding in the kidney, lung, heart, and spleen was greatest at 3 min after i.v. injection and declined rapidly with the disappearance of [3H]tamsulosin from the plasma. On the other hand, [3H]tamsulosin binding in the prostate and aorta peaked at 10 to 60 min after i.v. injection, and a considerable level of specific binding in both tissues persisted up to 240 min. The most sustained binding of [3H]tamsulosin occurred in the submaxillary gland. In vivo specific [3H]tamsulosin binding in rat tissues was effectively inhibited by the coinjection of low doses of unlabeled tamsulosin, prazosin, and terazosin with the radioligand but not by relatively high doses of yohimbine and propranolol. Based on estimated ID50 values, in vivo inhibitory effect of tamsulosin compared with prazosin was 5 to 14 times greater in rat tissues except the spleen, which showed 1.6 times less potent than prazosin. From ratios of ID50 (spleen) to ID50 (submaxillary gland) or ID50 (prostate), tamsulosin was 9 and 19 times, respectively, greater than prazosin in selectivity of alpha1 adrenoceptors in the submaxillary gland and prostate versus the spleen, respectively, suggesting that tamsulosin binds to alpha1A subtype with higher affinity than alpha1B subtype in vivo. The present study suggests that [3H]tamsulosin is a useful radioligand for in vivo measurement of alpha1 adrenoceptors in rat tissues.

Adrenergic alpha-1 Receptor Antagonists↗
PubMed1998

Ex vivo occupancy by tamsulosin of alpha1-adrenoceptors in rat tissues in relation to the plasma concentration.

At 0.5-12 h after oral administration of tamsulosin (2.3 micromol/kg) in rats, there was a significant decrease in specific [3H]prazosin binding in the prostate as compared to the control value. The greater decrease occurred in the submaxillary gland. The effect of tamsulosin was mainly due to a marked reduction of [3H]prazosin binding sites (Bmax) rather than to an increase in the dissociation constant (Kd). In contrast, there was only a slight decrease or no change in the [3H]prazosin binding in the spleen, heart, and cerebral cortex of tamsulosin-administered rats at 0.5-12 h. Oral administration of terazosin (21.7 micromol/kg) significantly increased Kd values for [3H]prazosin binding with little effect on Bmax values in the rat prostate at 3 and 6 h. The greater increases in Kd values were observed in the submaxillary gland, spleen and heart at 0.5-12 h. Terazosin had a slight effect on Kd values for the cerebral cortical [3H]prazosin binding. Tamsulosin was absorbed rapidly after oral administration at a dose of 2.3 micromol/kg in rats, and at 6 h, plasma concentration decreased markedly to approximately one-twentieth of the 0.5 h peak level. alpha1-Adrenoceptor occupancy was estimated as a percentage of decrease in Bmax values for [3H]prazosin binding in tissues of tamsulosin-treated rats compared with control rats. The alpha1-adrenoceptor occupancy by tamsulosin in the prostate and submaxillary gland occurred rapidly in parallel with the rise in plasma concentration of tamsulosin, and lasted for over 12 h despite the marked decrease in plasma concentration. Consequently, it is suggested that tamsulosin produces more selective and sustained occupancy in vivo of alpha1-adrenoceptors in the submaxillary gland and prostate of rats than in other tissues.

Administration, Oral↗
PubMed1997

Inhibition of brain cyclooxygenase-2 activity and the antipyretic action of nimesulide.

The antipyretic action and the mechanism of action of 4-nitro-2-phenoxymethanesulfonanilide (nimesulide), a new nonsteroidal antiinflammatory drug, were investigated in yeast-induced febrile rats. Yeast-injected rats developed marked fever and exhibited an approximately 7-fold increase in brain levels of prostaglandin E2 and an approximately 2-fold increase in the expression of cyclooxygenase-2 mRNA despite an almost unchanged expression of cyclooxygenase-1 mRNA. Nimesulide produced a dose dependent antipyretic action, which was stronger than that of indomethacin and ibuprofen, and decreased dose dependently the increased brain prostaglandin E2 levels, whereas it did not influence the expression of cyclooxygenase-2 mRNA. It inhibited markedly the enhanced brain cyclooxygenase activity, primarily cyclooxygenase-2, in vivo and dose dependently increased brain cyclooxygenase activity in vitro. These results suggest that the marked antipyretic action of nimesulide is primarily mediated through the selective inhibition of the activity of brain cyclooxygenase-2 induced under febrile conditions.

Analgesics, Non-Narcotic↗
PubMed1997

Brain pharmacokinetics and in vivo receptor binding of 1,4-dihydropyridine calcium channel antagonists.

Brain pharmacokinetics of 1,4-dihydropyridine (DHP) calcium channel antagonists and their in vivo receptor binding in mice were characterized. The area under the concentration vs time curve (AUCbrain) for [3H]nifedipine, [3H]nimodipine and [3H]PN 200-110 in mouse brain after intravenous injection was higher than that for [3H]amlodipine. Brain/plasma concentration ratios (AUCbrain/AUCplasm) for [3H]nimodipine and [3H]PN 200-110 were 3 to 5 times higher than those for [ H]nifedipine and [3H]amlodipine. Further, brain/heart concentration ratios (AUCbrain/AUCheart) for [3H]nifedipine, [3H]nimodipine and [3H]PN 200-110 were about 20 times higher than the ratio for [3H]amlodipine. A significant amount of specific binding in particulate fractions of mouse brain was detected in vivo by intravenous injection of [3H]nifedipine, [3H]nimodipine and [3H]PN 200-110 but not [3H]amlodipine. These data suggest that [3H]nifedipine, [3H]nimodipine and [3H]PN 200-110 are more extensively taken up into brain from plasma than [3H]amlodipine and bind to the receptor sites in brain parenchymal cells in a significant amount in vivo. In conclusion, the present simultaneous measurement of pharmacokinetics and in vivo receptor binding in mouse brain suggests an usefulness of calcium channel antagonists such as nimodipine in the pharmacotherapy of brain diseases.

Animals↗
PubMed1997

Production of amylase by the intestinal microflora in cultured freshwater fish.

The amylase-producing ability of the intestinal microflora in cultured specimens of ayu, carp, channel catfish, Japanese eel and tilapia was determined. Mean viable counts of aerobes and anaerobes ranged from 1.1 x 10(6) to 3.7 x 10(8) cfu g-1 and from 1.3 x 10(3) to 1.6 x 10(8) cfu g-1, respectively. Aeromonas spp. and Bacteroidaceae were predominant in four to five fish species. Of 206 strains examined, 65 (31.6%) produced > or = 0.01 U amylase ml-1. The percentage of producers differed among families and genera of bacteria and fish species. While 56% of the anaerobes produced amylase, only 20% of the aerobes did. More than 50% of Aeromonas, Bacteroidaceae and Clostridium strains produced amylase efficiently while Acinetobacter, coryneforms, Enterobacteriaceae, Moraxella, Plesiomonas and Streptococcus strains did not. High amylase production (> or = 0.05 U ml-1) was found in 12 strains, 11 from Aeromonas and one Pseudomonas. The percentage of high amylase producers in Japanese eel was lower than the other four fish (2-30%). These results strongly suggest that the amylase produced by the intestinal microflora play an important role in the digestion of starch in freshwater fish to some extent.

Amylases↗