Biomedical subjects

T Goda

Publications and source records attributed to T Goda.

At least 37 records · Page 2Linked to original sources

PubMed1999

Identification of a member of the serralysin family isolated from a psychrotrophic bacterium, Pseudomonas fluorescens 114.

An extracellular metalloprotease named No. 114 protease is one of the major secretions of a psychrotrophic bacterium, Pseudomonas fluorescens 114, the cold-adaptation mechanism of which has not been identified. In this study, we purified and cloned No. 114 protease, which is a single polypeptide having a molecular mass of 47 kDa. This protease contains a zinc-binding motif (HEXXHXUGUXH: X, arbitrary amino acid; U, bulky hydrophobic amino acid), glycine-rich repeats (GGXGXD) and no cysteine residue, which are the features specifically found in serralysin subfamily. No. 114 protease has its maximum activity at the temperature of 35-40 degrees C, which is about 20 degrees C lower than that of a serralysin from a mesophilic bacterium, Pseudomonas aeruginosa. All these results imply that No. 114 protease from this psychrophilic bacterium is a unique member of the serralysin group characterized by a low optimal temperature.

Adaptation, Physiological↗

PubMed1999

Developmental induction and villus-crypt distribution of retinol esterifying enzyme activities in chick duodenum.

Retinol absorbed and generated from dietary beta-carotene can be esterified by retinol esterifying enzyme(s) in intestinal absorptive cells. In this study, we observed the developmental changes and villus-crypt distribution of the activities of two retinol esterifying enzymes (lecithin-retinol acyltransferase (LRAT); and acyl-CoA-retinol acyltransferase (ARAT) in chick duodenum) to seek the possibility that these enzymes play distinct roles in retinol absorption and metabolism. Intestinal LRAT activity was barely expressed in embryonic stages until 2-3 d before hatching, when its activity becomes detectable; thereafter it abruptly increased to the maximal level at the third day of the posthatch period. In contrast, ARAT activity was present in the duodenum at the earliest stage examined, the 15th day of embryogenesis, and was elevated to the maximal level 3-4 d after hatching. An assay of LRAT and ARAT activities along the villus-crypt axis of the duodenum by a cryostat sectioning technique revealed that between the day of hatching and 1 d posthatch, an abrupt induction of LRAT activity occurred only in the villus region of the duodenum, where a coordinated induction of cellular retinol-binding protein, type II (CRBPII), was observed. In contrast, the rise in ARAT activity observed around the hatching period occurred at the broader portions of the villi including the area of villus-crypt junction. These observations in the developmental changes and distribution of LRAT and ARAT activities suggest that LRAT activity but not ARAT activity is closely related to the induction of CRBPII in the duodenum of developing chicks.

Acyltransferases↗

PubMed1999

[Relationship between the force of left atrial ejection to left ventricular function in arterial hypertension].

UNLABELLED: The left atrial ejection force (LAEF), defined as that force exerted by the left atrium (LA) to accelerate the blood into the left ventricle during atrial systole, is well accepted for the evaluation of LA systolic function. The aim of this study is to determine whether LAEF is a precursor of the impairement of LV systolic function in patients with arterial hypertension (HTN). For that purpose we studied LAEF in 36 patients with HTN (av. age 58 +/- 8 years) with LV hypertrophy (Lvmi > 134 g/m2 for men and > 110 g/m2 for women). LV systolic function estimated by the fractional shortening (FSh) was 35 +/- 4% (28 to 44); 32 normal subjects (NS) were also analyzed. All subjects were submitted to echo and doppler examinations. METHODS: LAEF was obtained by the formula: 1/3 x MVA x (A-vel)2, where MVA is mitral valve area measured by 2D echo while A-vel. is the late diastolic (atrial) mitral velocity. RESULTS: 1. LAEF increased significantly with age in NS (r = 0.78) p < 0.05). Age corrected LEAF was calculated as % LEAF = (actual LAEF/normal LAEF x 100. 2. Compared to NS. % LAEF was lower in HTN (78 + 25%). 3. There was a significant inverse correlation between LAEF and LV wall thickness (r = -0.46) (p < 0.05). 4. % LAEF was 66 +/- 31% in patients with FSh < 33% and 79 +/- 25% in those with FSh > 33% (p < 0.05). 5. In HTN with the duration > 15 years, % LAEF was lower than in patients with < 15 years (62 +/- 25 vs 76 +/- 24) (p < 0.05). CONCLUSIONS: 1. LAEF is decreased in more advance stages of HTN. 2. This impairment is related to LV hypertrophy and to the duration of the disease. 3. LAEF is a sensitive precursor for LV systolic deterioration in patients with hypertension.

Adult↗

PubMed1999

[Alteration of the longitudinal function of the left ventricle in hypertensives with systolic function of normal appearance].

UNLABELLED: Left ventricular (LV) transverse function is often used by the echocardiography to evaluate the systolic function in arterial hypertension (HTN). It would be interesting to know whether the LV long axis systolic dysfunction may precede the abnormalities of the transverse function in hypertension (HTN). For that purpose we evaluated by echo 36 patients (24 males, 12 females) with LV concentric hypertrophic (Lvmi > 134 g/m2 for men and > 110 g/m2 for women). All subjects were free of coronary heart disease and heart failure. According to the dimensions of the LV wall chickness (WTh) the HTN were subdivided in two groups: Group 1: Wth (12-14 mm) and Group 2: WTh (> 14 mm). The patients were compared to 30 healthy persons (control group) matched for age and LV systolic function (Fractional Shortening). METHODS: LV long axis shortening was measured at the septal and lateral sides of the mitral annulus using M-mode from the apical four chamber view. RESULTS: Compared to control group, septal long axis shortening fell significantly (p < 0.05) in proportion to the degree of the wall thickness: control group: 21 +/- 2 mm. Group 1: 16 +/- 1 mm and Group 2: 14 +/- 1 mm. Lateral shortening was reduced only in the Group 2 (15 +/- 2 vs 20 +/- 2 mm) (p < 0.05). LV wall thickness correlated significantly (p < 0.05) to septal and lateral shortening respectively (r = -0.51) and (r = -0.48). CONCLUSIONS: 1. Significant impairment of LV long axis function occurs in arterial hypertension with concentric hypertrophy even with normal transverse systolic function. 2. This alteration seems to be related to the dimensions of the LV wall thickness. 3. The prognostic implication of this disorder should be investigated further.

Adult↗

PubMed1998

Intestinal absorption of luteolin and luteolin 7-O-beta-glucoside in rats and humans.

In this study, we investigated the intestinal absorption of luteolin and luteolin 7-O-beta-glucoside in rats by HPLC. The absorption analysis using rat everted small intestine demonstrated that luteolin was converted to glucuronides during passing through the intestinal mucosa and that luteolin 7-O-beta-glucoside was absorbed after hydrolysis to luteolin. Free luteolin, its conjugates and methylated conjugates were present in rat plasma after dosing. This suggests that some luteolin can escape the intestinal conjugation and the hepatic sulfation/methylation. LC/MS analysis showed that the main conjugate which circulates in the blood was a monoglucuronide of the unchanged aglycone. Luteolin in propyleneglycol was absorbed more rapidly than that in 0.5% carboxymethyl cellulose. The plasma concentration of luteolin and its conjugates reached the highest level 15 min and 30 min after dosing with luteolin in propyleneglycol, respectively. HPLC analysis also allowed us to demonstrate the presence of free luteolin and its monoglucuronide in human serum after ingestion of luteolin.

Animals↗

PubMed1998

Dietary carbohydrates enhance lactase/phlorizin hydrolase gene expression at a transcription level in rat jejunum.

We have previously shown that dietary sucrose stimulates the lactase/phlorizin hydrolase (LPH) mRNA accumulation along with a rise in lactase activity in rat jejunum [Goda, Yasutake, Suzuki, Takase and Koldovský (1995) Am. J. Physiol. 268, G1066-G1073]. To elucidate the mechanisms whereby dietary carbohydrates enhance the LPH mRNA expression, 7-week-old rats that had been fed a low-carbohydrate diet (5.5% of energy as starch) were given diets containing various monosaccharides or sucrose for 12h. Among carbohydrates examined, fructose, sucrose, galactose and glycerol elicited an increase in LPH mRNA accumulation along with a rise in lactase activity in the jejunum. By contrast, glucose and alpha-methylglucoside were unable to elicit a significant increase in LPH mRNA levels. To explore a transcriptional mechanism for the carbohydrate-induced increases in LPH mRNA levels, we employed two techniques currently available to estimate transcriptional rate, i.e. RNA protection assays of pre-mRNA using an intron probe, and nuclear run-on assays. Both assays revealed that fructose elicited an increase in transcription of the LPH gene, and that the transcription of LPH was influenced only slightly, if at all, by glucose intake. These results suggest that certain monosaccharides such as fructose or their metabolite(s) are capable of enhancing LPH mRNA levels in the small intestine, and that transcriptional control might play a major role in the carbohydrate-induced increase of LPH mRNA expression.

Animals↗

PubMed1998

Peroxisome proliferator enhances gene expression of cellular retinol-binding protein, type II in Caco-2 cells.

Both the mRNA and protein of cellular retinol-binding protein, type two (CRBP(II)) are induced in rat intestine by high fat (corn oil) diet (Biochim. Biophys. Acta 1200, 34-40, 1994) as well as by dietary unsaturated long-chain fatty acids (J. Nutr. 125, 2039-2044, 1995). To gain an insight into the mechanism for this induction, we investigated whether CRBP(II) gene was activated by exposure of the human intestinal cell line, Caco-2 to a peroxisome proliferator (clofibric acid) and/or 9-cis retinoic acid. Northern blot hybridization revealed that Caco-2 cells endogenously expressed the mRNAs of peroxisome proliferator-activated receptor alpha (PPARalpha) and retinoid X receptor alpha (RXRalpha). The expression of the genes encoding CRBP(II), PPARalpha, and RXRalpha increased progressively during differentiation of Caco-2 cells. The cells exposed to 100 microM clofibric acid exhibited 70% greater CRBP(II) mRNA and the exposure of the cells to 100 microM clofibric acid in combination with 100 microM 9-cis retinoic acid exhibited 130% greater CRBP(II) mRNA level, indicating that the effect of the combination of them was additive. Neither PPARalpha mRNA nor RXRalpha mRNA level was enhanced by clofibric acid. In conclusion, our data suggested that the CRBP(II) gene expression may be enhanced by an activation of PPARalpha-RXRalpha heterodimer through some putative metabolite(s) formed via fatty acid-related metabolic pathway in the clofibrc acid-treated cells.

Alitretinoin↗

PubMed1998

Effect of intermittent feeding on the development of disaccharidase activities in artificially reared rat pups.

We investigated the effect of an intermittent feeding schedule on the development of disaccharidase activities in the small intestine of artificially reared (AR) rat pups. Rat pups were fitted with an intragastric cannula at 5 days of age. A milk formula similar to the composition of rat milk was supplied by intermittent gastric infusion over the following 15-19 days. The body weight gain and plasma corticosterone levels of the AR pups matched those of pups reared naturally by dams (MR pups). At 10, 15 and 19 days of age, the small intestine from the ligament to Treitz to the ileocecal junction was divided into three segments of equal length and enzyme activities were measured in each. At the age of 10 and 15 days, sucrase and isomaltase activities were undetectable in AR pups fed according to a controlled schedule from the early postnatal period. These activities were first detected in the middle segment of the small intestine at 9 days of age in both AR and MR pups. Sucrase and isomaltase activities at the age of 19 days were diurnal in AR pups, but arrhythmic in MR pups. We conclude that artificial rearing via the intermittent gastric infusion of a milk formula containing only lactose as the carbohydrate source did not prematurely increase intestinal sucrase and isomaltase activities. Diurnal changes started from the beginning of development of these enzyme activities in AR pups.

Animals↗

PubMed1998

The maltitol-induced increase in intestinal calcium transport increases the calcium content and breaking force of femoral bone in weanling rats.

Maltitol is a disaccharide alcohol that is produced by hydrogenation of maltose and exhibits resistance to intestinal disaccharidases. We demonstrated previously that maltitol stimulated transepithelial diffusional calcium transfer in the ileum, accompanied by an elevation of intestinal calcium absorption as well as calcium retention in the body. In this study we examined whether the maltitol-induced increase in the diffusional transfer of intestinal calcium absorption leads to an alteration of the physical properties of bones in the weanling rats which exhibit the maximal level of intestinal active calcium absorption. Rat pups were removed from dams at 24 d of age and were fed the diets containing either maltose (control) or maltitol and a requisite amount of calcium (0.52%) for 21 d. Balance studies performed during the final 5-d period showed that maltitol-fed rats had greater calcium retention and calcium absorption. The breaking force of femoral bones was 13% greater in the rats fed the maltitol diet than in controls. The calcium content and dry weight of both femurs and tibias, as well as the bone mineral density of tibias, were elevated in the rats fed the maltitol diet. In a separate experiment, gastric intubation of maltitol-containing diet increased the serum calcium concentration in the portal vein at 2 and 4 h compared to controls. These results indicate that the maltitol-induced increase in the intestinal calcium absorption through paracellular pathway leads to enhancement of the calcium content and the breaking strength in the bone of weanling rats.

Absorptiometry, Photon↗

PubMed1998

Enhanced absorption of calcium after oral administration of maltitol in the rat intestine.

The enhancing effects of maltitol (alpha-D-glucopyranosyl-1,4-sorbitol) on absorption of calcium by the rat intestine have been studied by use of [45Ca]CaCl2 in-vivo. After intragastric administration of [45Ca]CaCl2 solution with maltitol, plasma 45Ca concentration remained at the maximum level for more than 80 min, whereas for animals given [45Ca]CaCl2 solution without maltitol, plasma 45Ca concentration declined sharply after the peak. Determination of 45Ca radioactivity remaining in the various segments of the gastrointestinal tract revealed that administration of maltitol elicited slower gastric emptying and slower intestinal transit, resulting in extensive 45Ca distribution along the small intestine throughout the experimental period. The luminal contents of the small intestine were significantly higher in rats given maltitol than in the control group. These results suggest that the enhancing action of maltitol on intestinal calcium absorption could be attributed to reduced gastrointestinal calcium transit and increased luminal fluid content, presumably because of the osmotic activity of maltitol; this would not only accelerate the dissolution of calcium into the increased luminal contents, but also enable a larger area of the small intestine to absorb calcium for a longer period of time.

Administration, Oral↗

PubMed1998

Dietary fatty acids are possible key determinants of cellular retinol-binding protein II gene expression.

We previously found that dietary unsaturated fatty acids increase cellular retinol-binding protein type II (CRBP II) mRNA and its protein levels in rat jejunum. To obtain insight into mechanisms for its gene induction, we investigated the effect of depletion of dietary fat on CRBP II mRNA levels and we further examined whether dietary retinol is necessary for dietary fat-induced CRBP II gene expression. Feeding the fat-free diet, which contained a sufficient amount of vitamin A, repressed CRBP II mRNA accumulation by 50% within 1 day, and this low level was sustained over the next 9 days. Parallel to the decreased CRBP II mRNA level, the peroxisomal proliferator-activated receptor-alpha (PPAR-alpha) mRNA level in rat jejunum was decreased by long-term (7 days) feeding of an isocaloric low-fat diet compared with the control. Oral administration of corn oil in the animals fed vitamin A-free diet elicited approximately threefold accumulation of CRBP II mRNA within 6 h. However, the administration of 9-cis-retinoic acid brought about no accumulation of CRBP II mRNA. Even when rats were vitamin A-deficient, oral administration of corn oil, but not 9-cis-retinoic acid, caused an increase in jejunal CRBP II mRNA level. These results suggest that CRBP II gene expression in rat jejunum may be regulated predominantly by dietary fatty acids but little by dietary retinoids.

Alitretinoin↗

PubMed1997

Establishment of a novel host, high-red yeast that stably expresses hamster NADPH-cytochrome P450 oxidoreductase: usefulness for examination of the function of mammalian cytochrome P450.

A novel strain of Saccharomyces cerevisiae useful for expression studies of mammalian microsomal cytochrome P450s was established and named High-red yeast. Hamster NADPH-cytochrome P450 oxidoreductase (P450 reductase) cDNA to be introduced into yeast was isolated from a hamster liver cDNA library. The cDNA was 2421 bp long and contained an entire coding region for 667 amino acids. The NH2-terminal amino acid sequence deduced from the hamster P450 reductase cDNA was identical with that of the enzyme purified from hamster livers except for deletion of the initial methionine. A delta-sequence derived from yeast retrotransposon Ty was cloned and used as a sequence for homologous recombination in a yeast genome. S. cerevisiae YPH500 was transformed with a multi-integration cassette containing the expression unit of the hamster P450 reductase and the delta-sequence. The transformant showing the highest activity of the P450 reductase was named High-red yeast. High-red yeast carried more than six copies of the multi-integration cassettes in a single chromosome and retained the multi-integration cassettes over a period of 100 generations under nonselective culture conditions, indicating that this yeast was a mitotically stable transformant. The microsomes prepared from High-red yeast had 20 times the P450 reductase activity of the microsomes prepared from the parental yeast. Due to the high activity of the hamster P450 reductase, the 7-ethoxycoumarin deethylase activity of mouse CYP1A1 expressed in High-red yeast was 250 times higher than the activity of mouse CYP1A1 expressed in the parental yeast.

Amino Acid Sequence↗

PubMed1997

Cloning of chick cellular retinol-binding protein, type II and comparison to that of some mammals: expression of the gene at different developmental stages, and possible involvement of RXRs and PPAR.

We cloned chick cellular retinol-binding protein, type two (CRBP II) cDNA and compared it with those of some mammals. The deduced amino acid sequence showed that chick CRBP II was one amino acid greater in size than those of mammals, and the nucleotide sequence of chick CRBP II shared 72%-75% similarity with those of mammals. RNA blot hybridization analysis showed that CRBP II transcript of 0.7 kb was first detected in the duodenum of day-18 embryonic chick, and exhibited a rapid increase during 24 hr around the hatching. Northern blot hybridization also revealed that the transcripts of two types of retinoid X receptors (RXR alpha and RXR gamma) and peroxisome proliferator-activated receptor (PPAR) were expressed in the chick duodenum at hatching. The organ culture of day 16 embryonic chick duodenum showed that the addition of 9-cis retinoic acid in the medium caused a significant increase in CRBP II mRNA levels. In addition, arachidonic acid, from which putative ligands for PPAR were supposed to be generated, was accumulated around hatching in the duodenum. The results may suggest that the abrupt increase of the CRBP II gene expression in the chick duodenum around hatching may be related with RXRs and/or PPAR.

Animals↗

PubMed1997

Perilla oil prevents the excessive growth of visceral adipose tissue in rats by down-regulating adipocyte differentiation.

We examined the effect of dietary oils with different fatty acid compositions on the growth of visceral adipose tissue in rats. Rats were fed for 4 mo starting at weaning a basal diet containing (12 g/100 g diet) perilla oil rich in (n-3) polyunsaturated fatty acids (PUFA), safflower oil rich in (n-6) PUFA, olive oil rich in monounsaturated fatty acid, or beef tallow rich in saturated fatty acids. The amount of food consumed and body weight gain did not differ among the four dietary groups. The weight of the epididymal fat pad and the serum triglyceride concentration in perilla oil-fed rats were significantly lower (P < 0.05) than those of olive oil- and beef tallow-fed groups. The product of [(volume of individual adipocytes) x (number of adipocytes in epididymal fat pad)], which presumably represents total adipocyte volume in the fat pad, was significantly lower (P < 0.05) in perilla oil-fed rats than in beef tallow- and olive oil-fed groups. Expression of the late genes of adipocyte differentiation, peroxisome proliferator-activated receptor alpha, adipocyte P2 and adipsin, was significantly (P < 0. 05) down-regulated in epididymal fat tissue of rats that had been fed perilla oil rather than beef tallow or olive oil, whereas expression of the early gene, lipoprotein lipase, was not significantly affected. Greater levels (P < 0.05) of (n-3) PUFA in the membrane phospholipid fraction of the fat tissue were observed in perilla oil-fed rats than in the other dietary groups. These results suggest that perilla oil or (n-3) PUFA prevents excessive growth of adipose tissue in rats at least in part by suppressing the late phase of adipocyte differentiation.

Adipocytes↗

PubMed1997

A possible role of a nuclear factor NF-LPH1 in the regional expression of lactase-phlorizin hydrolase along the small intestine.

Lactase-phlorizin hydrolase (LPH), an enterocyte-specific disaccharidase, displays not only a post weaning decline but also regional differences in the small intestine. To investigate the mechanisms of regional LPH expression along the small intestine, the correlation between LPH mRNA abundance, lactase activity and the amount of a nuclear factor (NF-LPH1) binding to a cis-element was determined in various intestinal segments of suckling and adult rats. In suckling rats, both LPH mRNA and lactase activity were expressed at maximum in the jejunum, but they were hardly detected in the colon. In adult rats, both LPH mRNA and lactase activity were the highest in the jejunum and virtually absent in the ileum. Lactase activity and LPH mRNA abundance in suckling rats were 2-3 times more than those of adult rats in all regions of the small intestine. An electromobility shift assays of nuclear proteins revealed that NF-LPH1 was present in rat small intestine as well as in Caco-2 cells. The amount of NF-LPH1 binding to the cis-element was also approximately 2-fold more in the intestinal nuclear extracts of suckling rats than that of adult rats. NF-LPH1 was detected in all regions of the small intestine in both suckling and adult rats. In both cases, the amounts of NF-LPH1 binding to the cis-element increased from the duodenum to upper jejunum, and decreased toward the ileum. The coordinate postnatal declines of LPH mRNA and NF-LPH1 expression in various regions of the small intestine suggest that NF-LPH1 might be involved not only in the regulation of postnatal LPH gene expression but in region-specific LPH gene expression as well.

Animals↗

PubMed1996

Relationship between perinatal appearance of cellular retinol-binding protein, type II and retinal reductase activity in chick liver.

To explore a role of the transiently appearing cellular retinol-binding protein, type II (CRBP(II)) in perinatal chick liver, we have examined whether the relationships exist among the perinatal changes in hepatic CRBP(II) protein and mRNA levels, retinal reductase activity and beta-carotene levels in liver and serum. Northern blot analysis for hepatic CRBP(II) revealed a transient expression of CRBP(II) mRNA around hatching. The protein of CRBP(II) was also expressed transiently and the highest levels of CRBP(II) were found in the livers 1-3 days after birth. The retinal reductase activity was very low at embryonic age, but its activity rapidly rose at hatching, peaking at 1 day after birth, followed by a gradual decrease to a lower level in 7-day-old chicks. This perinatal pattern of the retinal reductase activities was similar to the pattern of transient appearance of the hepatic CRBP(II), and was also paralleled to the developmental changes in serum and liver beta-carotene concentrations. These findings suggest that hepatic CRBP(II) transiently appearing during the perinatal period may involve in metabolizing hepatic beta-carotene, directing the retinal to the retinal reductase and leading further to the subsequent esterification of the converted retinol.

Alcohol Oxidoreductases↗

PubMed1996

Maltitol increases transepithelial diffusional transfer of calcium in rat ileum.

We explored the mechanism whereby maltitol causes an increase of calcium absorption in the lower small intestine using everted ileal segments of rats. Under the calcium concentrations tested (1-20mM), which enabled us to assess the diffusional calcium transfer, maltitol in the mucosal-side medium (100mM) caused a 155% greater transepithelial calcium transfer as compared with the segments incubated without sugars. The maltitol-induced increment of calcium transfer was significantly higher than those elicited by glucose, sorbitol and maltose, and this increase was completely inhibited by W7, a calmodulin antagonist. Thus, our results suggest that maltitol might modulate the permeability of calcium through paracellular path, which possibly involves the activation of calmodulin.

Animals↗

PubMed1996

Lack of lecithin: retinol acyltransferase activity in chick lungs.

Our previous study revealed that no retinyl esters were detectable in chick and hen lungs, suggesting that the retinol esterification system may be absent in these tissues. This possibility encouraged us to investigate whether chick lungs exhibit the activity of a retinol esterifying enzyme, i.e., lecithin: retinol acyltransferase (LRAT). The LRAT activity was assayed with dilauroyl phosphatidylcholine and either complex of retinol-cellular retinol-binding protein, type two or retinol-cellular retinol-binding protein in microsomal preparations of lung, duodenum and liver of 7-day-old chicks. Relatively high levels of LRAT activity were present in the duodenum and the liver of chicks as well as in the rat lung. However, the chick lung exhibited no LRAT activity. The lungs of both rat and chick showed similar and low levels of acyl-CoA: retinol acyltransferase (ARAT) activity, but only rat lung, but not chick lung, contained a detectable amount of retinyl esters. Thus, the retinyl ester storage in the lung seems to depend on the presence of LRAT activity in the lung, but it is independent of the presence of ARAT activity in the lung. The absence of LRAT activity and retinyl esters in the chick lung suggests that the retinol in the chick lung may not be provided from retinyl ester storage, and the retinol transferred directly from serum should be utilized to generate retinoic acid.

Acyltransferases↗