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Heparin administration to diabetic rats caused no change in VLDL, an increase in IDL and a decrease in LDL on electrophoretic analysis of plasma lipoproteins, while the administration to control rats markedly decreased VLDL and increased IDL and LDL. Both hepatic triglyceride lipase (HTGL) and lipoprotein lipase (LPL) activities in the postheparin plasma were lower in the diabetic rats than in the controls, and the reduction of HTGL activity was greater than that of LPL activity in the diabetic rats. The LPL activity in the adipose tissue was lower in the diabetic rats than in the controls, but the activities in the cardiac and skeletal muscles were similar in the two rats. The HTGL-catalyzed fatty acid (FA) releases from the diabetic VLDL and IDL were lower than those from the normal rat VLDL and IDL, while the LPL-catalyzed FA release in the diabetic rats was not different from those in the controls. The decreases in LPL and HTGL activities and the markedly impaired susceptibility of IDL to HTGL coincide well with the postheparin changes in plasma lipoproteins in diabetic rats, an increase in IDL and a decrease in LDL.

Rats with alloxan-induced diabetes developed severe atherosclerotic lesions when they were maintained on a 0.25% cholesterol diet for one year. The atheromatous changes developed at the aortic arch, appeared as early as 3 months after the start of the experiment, and increased thereafter. The diabetic rats also developed atherosclerosis when they were fed standard rat chow, but the area of the atheromatous lesion was about one tenth of that in rats fed the high-cholesterol diet. Normal rats did not develop atherosclerosis even when fed the high-cholesterol diet for one year. The alloxan diabetic rats showed no increase in body weight, but developed serum glucose levels as high as 600-800 mg/dl as well as high serum cholesterol levels and lower serum HDL-cholesterol levels. The development of atherosclerosis in these rats was significantly related to an increase in the serum cholesterol/phospholipid ratio, the atherogenic index (TC-HDLC/HDLC), and the serum total cholesterol level, but was not related to the serum glucose, HDL-cholesterol, triglyceride, or lipid peroxide levels. These relationships were found as early as B-16 weeks after the start of the experiment. These data suggest that the serum cholesterol/phospholipid ratio, the atherogenic index, and the total cholesterol level are important risk factors for the development of atherosclerosis in rats with alloxan diabetes.

In vitro glycation of very low density lipoprotein (VLDL) reduced the susceptibility to lipoprotein lipase (LPL) as the level of glycation increased. Addition of reduced glutathione to an incubation medium of serum and glucose interfered with glycation of serum proteins when the concentration of reduced glutathione was higher than 10 mM. At concentrations higher than 25 mM, it also significantly prevented the glycation induced reduction of fatty acid releases from VLDL by LPL. There were no such effects on glycation of serum protein and the fatty acid release from the addition of aminoguanidine. By contrast, addition of D-lysine enhanced glycation of serum proteins by glucose and further decreased fatty acid release from VLDL by LPL. From these results, it is suggested that glycation of VLDL decreases the susceptibility of VLDL to LPL. Delayed catabolism of VLDL in diabetic patients is considered partly caused by glycation of apoproteins, which renders VLDL less sensitive to LPL, in addition to the decreased LPL activity in diabetes mellitus.

Alloxan-diabetic rats were kept on an ordinary or 0.25% cholesterol supplemented diet for up to 12 months, and changes in the serum lipid and lipoprotein levels were examined. The diabetic rats showed IRI levels of 3-5 IU/ml, which were 1/5-1/10 that of the normal rats, and about 10 times higher serum glucose levels than the normal rats. The diabetic rats consumed 1.5-2 fold amounts of diet but their body weights were almost constant. The diabetic rats showed marked hyperlipidemia, especially in the cholesterol and triglyceride levels. The phospholipid level also increased but for a lesser extent and the c/p ratio increased. The serum lipoprotein levels increased in the diabetic rats, 5-10 times in the ordinary diet fed groups and 10-20 times in the cholesterol diet fed groups. Chylomicron, VLDL, IDL and LDL increased but HDL decreased. These changes were more significant in the diabetic rats fed the cholesterol diet. The triglyceride levels in the lipoprotein fractions increased in the diabetic rats, but the increase in cholesterol was more significant and the relative composition ratios of triglyceride decreased. The composition ratios of phospholipids, however, remained almost constant in all the lipoprotein fractions. The increase in IDL, especially cholesterol in the IDL fraction, was remarkable in the diabetic rats. The responsiveness of the diabetic rat VLDL to lipoprotein lipase (release of free fatty acids) was less than a half of that of the normal rat VLDL. In conclusion, the diabetic rats showed an increase in triglyceride but more significant increase in cholesterol in the lipoprotein fractions. These changes in serum lipid and lipoprotein levels and compositions appeared as early as 3 months after the alloxan injection and lasted for 12 months without any progress in the disturbance.

In order to clarify the relationship between composition and lipolytic responses to lipoprotein lipase (LPL), very low density lipoproteine (VLDL) from rats or humans were incubated with a commercially available LPL or with a partially purified LPL from postheparin human plasma and fatty acids released from VLDL were determined in vitro. VLDL from rats fed a diet containing 0.25 cholesterol for 6 months were rich in cholesterol and poor in triglycerides, and released less fatty acids from incubation with LPL than those from control rats. VLDL from normo- and hypertriglyceridemic human subjects were incubated with LPL. The fatty acid release poorly correlated with the apoprotein ratios of VLDL, apo C-III/C-II, B/E, and C/E with the exception of apo B/C, but it correlated well with the ratio of triglyceride/either one of the surface components including total apoproteins, free cholesterol and phospholipids in VLDL or the ratio of the triglyceride/total sum of the surface components. The correlation coefficients between fatty acid release and a ratio of triglyceride/total surface components were 0.774 (using the commercially available LPL) and 0.786 (using the partially purified human LPL). The fatty acid release increased after pretreatment of VLDL with phospholipase A2. The phospholipid content of VLDL was reduced without significant changes in other VLDL components. Thus, the responses of VLDL to LPL treatment may depend mainly upon the surface: core relationship of VLDL rather than its apoprotein composition except in rare clinical cases such as apo C-II deficiency.

Real-time virtual sonography (RVS) is a diagnostic imaging support system, which provides the same cross-sectional multiplanar reconstruction images as ultrasound images on the same monitor screen in real time. The purpose of this study was to evaluate radiofrequency ablation (RFA) assisted by RVS and CT for hepatocellular carcinoma (HCC) undetectable with conventional sonography. Subjects were 20 patients with 20 HCC nodules not detected by conventional sonography but detectable by CT or MRI. All patients had hepatitis C-induced liver cirrhosis; there were 13 males and 7 females aged 55-81 years (mean, 69.3 years). RFA was performed in the CT room, and the tumor was punctured with the assistance of RVS. CT was performed immediately after puncture, and ablation was performed after confirming that the needle had been inserted into the tumor precisely. The mean number of punctures and success rates of the first puncture were evaluated. Treatment effects were evaluated with dynamic CT every 3 months after RFA. RFA was technically feasible and local tumor control was achieved in all patients. The mean number of punctures was 1.1, and the success rate of the first puncture was 90.0%. This method enabled safe ablation without complications. The mean follow-up period was 13.5 month (range, 9-18 months). No local recurrence was observed at the follow-up points. In conclusion, RFA assisted by RVS and CT is a safe and efficacious method of treatment for HCC undetectable by conventional sonography.

The effect of ascorbic acid deficiency on serum and liver cholesterol, phospholipid and triglyceride levels, serum lipoprotein levels and serum lipoprotein cholesterol levels were examined in male rats with a hereditary defect in ascorbic acid synthesis (ODS rats). Male homozygotes (od/od) and male rats of their parent strain (+/+) were each divided into four treatment groups and were fed vitamin C-deficient or vitamin C-replete diets containing either 0 or 0.5% cholesterol. During the 3-wk feeding-period the ODS (od/od) rats fed the vitamin C-deficient diet gradually decreased food intake, resulting in a lower body weight than that of od/od rats given ascorbic acid. The serum cholesterol level was significantly higher in the vitamin C-deficient od/od rats fed the cholesterol diet, and it tended to be higher in those fed the control (0% cholesterol) diet, whereas the liver lipid levels remained unchanged relative to those in od/od rats fed the vitamin C-replete diet. The serum very low density lipoprotein and high density lipoprotein (HDL) cholesterol levels were lower in od/od rats fed the vitamin C-deficient diet without cholesterol, but intermediate density lipoprotein and low density lipoprotein cholesterol levels were markedly higher in the vitamin C-deficient od/od rats than in od/od rats given ascorbic acid, regardless of dietary cholesterol level. The ratio of HDL2 cholesterol to HDL3 cholesterol was also higher in the vitamin C-deficient od/od rats. The parent strain of the od/od rats (+/+) showed no change due to vitamin C deficiency. These results suggest that vitamin C deficiency delays low density lipoprotein metabolism and produces hypercholesterolemia in male od/od rats.

Cholesterol and bile acid leves were examined in young (8 weeks), middle-aged (12 months) and old (24 months) germ-free male rats, and young (8 weeks) and middle-aged (12 months) conventional male rats. The plasma cholesterol levels were higher in the aged rats, being more marked in the conventional rats. The liver cholesterol levels also increased with age and the increases were almost identical for both groups. No age-related changes were found in the biliary bile acid secretion, the pool size and distribution of bile acids in the bile, small intestine and large intestine, nor in the turnover frequency of bile acids, but the pool size in the young and middle-aged germ-free rats was much larger than that in the conventional rats. The turnover frequency was less in the germ-free rats. The bile acid synthesis presumed from the fecal bile acid excretion decreased in the aged germ-free rats but not in the conventional rats. A most remarkable age-related change was found in the bile acid composition; cholic acid increased and beta-muricholic acid derived from chenodeoxycholic acid in the rat decreased by aging, resulting in an increase of the CA/CDCA ratio (bile acids belonging to the cholic acid group/bile acids to the chenodeoxycholic acid group) in the bile, feces and pool. These results suggest that cholic acid synthesis increases while chenodeoxycholic acid synthesis is impaired by aging in rats.

Serum cholesterol, triglyceride and phospholipid levels, liver cholesterol concentration, bile flow, biliary cholesterol, phospholipid and bile acid secretion rates, fecal sterol and bile acid levels and their bile acid compositions were examined in young-old parabiotic rats and compared with those in young and old control rats and young-young parabiotic rats. Bile acid composition was expressed in terms of the cholic acid group/chenodeoxycholic acid group (CA/CDCA) ratio. Body weight (BW) gain decreased after parabiosis especially in old rats, but the liver weight (g/100 g BW), diet-intake, feces dry weight, liver cholesterol concentration and fecal sterol level were almost the same in all the groups. The biliary bile acid secretion rate was higher and the fecal bile acid level was lower in old rats than those in young rats but both the levels became comparable with those in young rats after parabiosis of old rats with young rats. Young rats, however, showed no changes in these levels after parabiosis. The serum cholesterol level and the biliary and fecal CA/CDCA ratios in old rats were higher than those in young rats but decreased after parabiosis with young rats, although they were still higher than those in young rats. The serum cholesterol level in young rats increased after parabiosis with old rats, but not after parabiosis with young rats, and the fecal bile acid level and the CA/CDCA ratio were not changed in either case. It is concluded from these findings that the serum cholesterol level and the CA/CDCA ratio increased with age and that these increases were prevented after parabiosis with young rats, while young rats, although their serum cholesterol level was increased, showed no increase in the CA/CDCA ratio after parabiosis with old rats.

The effects of cholesterol feeding on serum and liver cholesterol levels, fecal and biliary bile acid levels, bile acid pool size and bile acid composition were examined in 2-, 12- and 24-month-old male germ-free rats. The major bile acids in these animals were cholic and β-muricholic acids. Cholesterol feeding increased synthesis of bile acids by 3- to 4-fold, especially that of chenodeoxycholic acid (mainly β-muricholic acid in the rat), decreasing the cholic acid/chenodeoxycholic acid (CA/CDCA) ratio in all rats regardless of age, even though the CA/CDCA ratio increased as a linear function of age in both diet groups. Cholesterol feeding increased the serum cholesterol level markedly in aged rats. This hypercholesterolemia may be produced by the increase in CA/CDCA ratio in aged rats.

Wistar male rats were treated for six days with broad spectrum beta-lactam antibiotics, latamoxef, and cefotaxime. On the seventh day, the number of fecal anaerobic microbes decreased, total fecal bile acids decreased, and bile acid pools increased. Secondary bile acids such as beta-hyocholic, hyodeoxycholic, lithocholic, and deoxycholic acids decreased in the feces while the primary bile acids, cholic, beta-muricholic, and chenodeoxycholic acids, became predominant. Coprostanol, a microbial metabolite of cholesterol, also disappeared from the feces during the treatment. The cecum enlarged to almost twice the size of that in control rats, whereas the liver weight was not significantly changed. After treatment was stopped, the number of fecal microbes returned to the initial counts within a week, but restoration of bile acid and cholesterol metabolism required at least three weeks.

Normal and alloxan diabetic rats were kept on a 0.25% cholesterol diet for 12 months and the changes in serum cholesterol levels, and fecal excretion of sterols and bile acids were examined to elucidate the influence of changes in bile acid metabolism on manifestations of hypercholesterolemia and development of atheromatous lesions. Diabetic rats fed the cholesterol diet showed increases in bile acid synthesis and in the cholic acid group/chenodeoxycholic acid group (CA/CDCA) ratio, and developed significant hypercholesterolemia and atheromatous lesions. In contrast, normal rats showed increased bile acids synthesis but a decreased CA/CDCA ratio after feeding with the cholesterol diet, and developed neither hypercholesterolemia nor atheromatous lesions. Fecal sterol excretion and the cholesterol/sitosterol ratio decreased in diabetic rats. Positive correlations were found between the cumulative serum cholesterol level and the atheromatous lesion area, and between the fecal CA/CDCA ratio and the serum cholesterol level, in the latter of which the correlation was higher in rats on the cholesterol diet than in those on the standard diet. These findings suggest that alteration of bile acid metabolism with increases in cholic acid synthesis and CA/CDCA ratio in diabetic rats enhances cholesterol absorption to produce significant hypercholesterolemia, which in turn leads to development of atheromatous lesions.

Bile acid synthesis from orally administered (14)C-cholesterol or from (14)C-mevalonic acid administered intravenously were examined in male and female 2-, 12- and 24-month-old rats. About 5-9% of the '4C-cholesterol administered was recovered as bile acids from the small intestine 3 days after administration. The value in the case of (14)C-mevalonic acid was about 1/10 that of (14)C-cholesterol. Major bile acids were cholic acid and beta-muricholic acid, and the formation ratio of cholic acid increased in aged rats, although no further difference was found between 12- and 24-month-old animals of either sex. Male rats formed more beta-muricholic acid than females at all ages examined. In addition, no significant difference was found in the bile acid composition between both precursors, (14)C-cholesterol and (14)C-mevalonic acid.

Activation and inactivation of hepatic 3-hydroxy-3-methylglutaryl coenzyme A reductase, which is a key enzyme of cholesterol synthesis, were examined in young and aged rats in vitro . The reductase activity in the liver microsomes of aged rats was always lower than that of young rats at various experimental conditions in vitro . But activation and inactivation of the reductase could operate on liver microsomes in aged rats as well as in young rats. Function of hepatic cytosol activator in aged rats seemed to be identical to that in young rats.

Incorporations of squalene and mevalonate into cholesterol in hepatic microsomes and cytosol from growing or young rats were higher than those from adult rats. When the microsomes from growing or young rats were combined with the cytosol from adult rats instead of young cytosol, the incorporation rates of squalene and mevalonate into cholesterol were decreased. When adult microsomes were combined with young cytosol, cholesterol synthesis from mevalonate was increased but that from squalene was not. Cytosol fractions from cholesterol fed rats did not inhibit the cholesterol synthesis from squalene in the microsomes from non-treated rats, and the normal cytosol did not influence the cholesterol synthesis in the microsomes from cholesterol fed rats, suggesting the elevation of serum cholesterol in aged animals did not affect the activity of cytosol fraction. It is concluded that the function of hepatic sterol carrier protein is probably impaired by ageing process. The decrease of hepatic cholesterol synthesis in old microsomes in vitro is difficult to be recovered by the substitution of young sterol carrier protein for adult one. The decreased function of sterol carrier protein is not derived from hypercholesterolemia which is often observed in the aged.

Effects of sodium cholate, deoxycholate, chenodeoxycholate, and lithocholate on serum and liver cholesterol levels, bile flow, biliary cholesterol, phospholipids, and bile acids, and fecal sterols and bile acids were examined in Wistar strain male rats fed either an ordinary diet or a 2% cholesterol diet. Cholate and deoxycholate increased serum and liver cholesterol levels, serum pre beta-lipoprotein, bile flow, and biliary secretion of cholesterol, phospholipids, and bile acids, but chenodeoxycholate and lithocholate did not. The total amounts of sterols and of bile acids in the feces did not differ between the cholate and the chenodeoxycholate groups. All the bile acids except lithocholate decreased fecal coprostanol when the diet included cholesterol. Cholate and deoxycholate produced similar bile acid compositions in the bile and feces, as was the case between chenodeoxycholate and lithocholate, though chenodeoxycholate slightly increased the amount of muricholic acids, and lithocholate that of hyodeoxycholic acid, in the feces. The effects of cholate and deoxycholate are similar to each other but different from that of chenodeoxycholate or lithocholate in rats. Cholate causes marked accumulation of cholesterol in tissues, increased bile flow and biliary lipid secretion but chenodeoxycholate does not. Cholate is absorbed much more efficiently than chenodeoxycholate.

Stereological analysis at the electron microscope level was performed on zona fasciculata and zona reticularis of the adrenal cortex of male rats maintained on normal rat chow, clofibrate (hypolipidemic drug), cholesterol-rich diet or cholesterol-rich diet plus clofibrate. The purpose of this study is to know whether the alteration in the serum cholesterol level is accompanied by an alteration in the ultrastructure and steroidogenic activity of the adrenal cortex, and to compare these changes with those of Leydig cells reported previously. The corticosterone level in both serum and the adrenal tissue of cholesterol-fed rats remained unchanged. Treatment of the cholesterol-fed rats with clofibrate caused a significant rise in the serum corticosterone level but the concentration in the adrenal remained unchanged. Lipid droplets increased in number and volume significantly in both cortical zones in all experimental groups as compared with the control group. But neither cholesterol feeding nor clofibrate treatment of normal rats caused a change in the volume or surface area of smooth endoplasmic reticulum (ER). Treatment with clofibrate on the cholesterol-fed rats resulted in a decrease in the volume of smooth ER in both cortical zones. Mitochondria showed no change except for a decrease in volume and inner membrane surface area of zona reticularis of cholesterol-fed rats. Peroxisomes did not proliferate but rather decreased in clofibrate-treated rats. These changes in the adrenal cortex were different from those in Leydig cells. Possible reasons for these differences were discussed.

The normal levels of apolipoproteins in Japanese were investigated by the single radial immunodiffusion method. No differences were seen between the males and females in the apolipoprotein A-I, B, and C-III levels. However, the levels of apolipoproteins A-II and C-II were higher in the males, while that of apolipoprotein E was higher in the females. These differences were statistically significant. Except for apolipoprotein E, the apolipoprotein levels tended to increase with age more in the females than in the males. The apolipoprotein E level showed a statistically significant positive correlation not only with the total cholesterol level but also with the high density lipoprotein-cholesterol level.

Bronchopulmonary washings from a patient with pulmonary alveolar proteinosis who underwent therapeutic pulmonary lavage were examined. There were large amounts of protein and lipids of which main classes were phospholipid, choleterol and free fatty acid. The major component of phospholipids recovered from the washing was lecithin rich in palmitic acid. We also found a high IgG level in the washings. Both the findings of free cholesterol in high concentration in the washings and the electrophoretic pattern of protein in the washings suggested that the alveoli-filling material of our patient was not wholely derived from passive transudation of plasma constituents.

Age-related changes in serum and liver cholesterol, phospholipid and triglyceride levels, serum lipoproteins, biliary secretion of cholesterol, phospholipid and bile acids, and fecal excretion of sterols and bile acids were examined in Sprague-Dawley and Wistar strain male rats, 7 to 106 weeks in age. Serum and liver lipid levels increased with age in both strains but the liver phospholipid level remained unchanged. The proportion of serum alpha-lipoprotein increases and that of beta- and prebeta-lipoproteins slightly decreased. Cholesterol and phospholipids in low density lipoprotein and cholesterol in high density lipoprotein fractions also increased with age. Bile flow and biliary secretion of cholesterol and bile acids decreased in aged rats, but when they were expressed in terms of units per rat they were almost constant without regard to age. Pool size, synthesis, secretion, and turnover frequency of bile acids also did not change when they were expressed per rat, though 7-week-old rats showed a low value for turnover frequency. Biliary secretion of phospholipid, however, increased in aged rats. Biliary secretion of chenodeoxycholic and alpha-muricholic acids decreased but that of cholic and hyodeoxycholic acids increased. Daily excretion of feces and fecal neutral sterols decreases in aged rats but the excretion of bile acids remained constant regardless of age. The ratio of coprostanol and cholesterol in the total sterols was not affected. Fecal lithocholic, beta-muricholic and P10 (probably omega-muricholic) acids were decreased with age but the other bile acid components were not changed or were slightly increased.

In order to investigate the effect of hepatic cholesterol flux on biliary bile acids, Triton WR 1339 and orotic acid were administered to rats, and the biliary cholesterol, phospholipids and bile acids were analyzed together with serum lipoproteins and hepatic lipids. Triton, which raised serum very low density lipoprotein and lipid levels and decreased serum high density lipoprotein liver lipid levels, increase the biliary cholic acid group/chenodeoxycholic acid group ratio (CA/CDCA) in the bile without affecting the total amount of bile acids and the other biliary lipids. Orotic acid, which decreased serum lipid and lipoprotein concentrations and increased liver lipid levels, increased the biliary excretion of cholesterol and phospholipids, but produced no significant change in the total amount of bile acids and in the CA/CDCA ratio in bile.

The effects of aging on serum lipids, lipoproteins and apolipoprotein C subclasses in very low density lipoprotein (VLDL) were investigated in healthy male subjects aged from the 1st to the 9th decade. The serum cholesterol, phospholipid and triglyceride concentrations, the serum beta-lipoprotein concentration determined immunologically, and the beta-lipoprotein percentage determined by electrophoresis showed the lowest levels in the 2nd decade, increased gradually with age, attained the highest level in the 6th to 7th decade and slightly declined in the 9th decade. The VLDL-low density lipoprotein (LDL) cholesterol level changed almost in parallel with the serum total cholesterol level, but the HDL cholesterol level and the apolipoprotein A concentration remained almost constant showing no age-related change. The free cholesterol percentages in every lipoprotein fraction and the apolipoprotein content in LDL were higher in the subjects in the 6th and 7th decade than those in the 2nd to 3rd decade. The apo C II/C III ratio in VLDL increased with age. These data suggest that the ability to active lipoprotein lipase may not be impaired but the lecithin:cholesterol acyltransferase (LCAT) activity declines with age.

Changes of the metabolism of lung phospholipids and alveolar wash lipids were studied in guinea pigs and rats with experimental pneumonitis produced by the injection of complete Freund's adjuvant. The amount of total lipid obtained by lung lavage decreased significantly in contrast to a marked increase in the content of total protein in treated animals. Among the lipids in the pulmonary washings, only phospholipids were strikingly reduced, and free fatty acids were increased somewhat. However, the composition of phospholipids was not affected by the treatment. The in vitro incorporation of 1-14C-acetate into the total lipid and phospholipids in the lung with pneumonitis was slightly lower compared to controls, but the difference was not significant. The in vitro 1-14C-palmitic acid incorporation into phospholipids of the lesioned lung, was also similar to that in controls. Thus, phospholipid biosynthesis in the lung was not affected by pneumonitis. On the other hand, the in vitro activity of total phospholipase in rat lung with experimental pneumonitis was enhanced significantly. These results suggest that phospholipase activity is increased in the diseased lung and this may participate in the process of the inflammatory reaction. The possible role of activated macrophages in the inflammatory response of the lung is discussed.

Clinofibrate was given to 15 patients with hyperlipidemia, for 6–8 weeks at the daily daily dose of 600 mg, and its effect on 3 biliary lipid components (cholesterol, bile acids and phospholipids) and on the lithogenic index was investigated. After clinofibrate treatment, 6 of the patients were given 1.5 g/day clofibrate for 6–8 weeks to compare the effect of clofibrate with that of clinofibrate. The molar percentages of biliary cholesterol and phospholipids to the total. mol number of the 3 biliary lipid components decreased, and that of bile acids increased during clinofibrate administration. In this way, the molar ratio of bile acids to cholesterol increased during the treatment. Neither the lithogenic index calculated by the formula of Admirand and Small nor that of Hegardt, Dam and Holzbach was altered significantly by the treatment. There was no apparent relationship between the effect of the drug on the lithogenic index and any of the factors initial lithogenic index, rate of decrease of serum lipids, or type of hyperlipidemia. Although clofibrate had no significant effect on the maximum solubility of cholesterol in the bile, the molar percentage of biliary cholesterol was elevated and the lithogenic index increased as compared with the control and clinofibrate period. No significant influence on bile acid composition in the bile was observed, with either clinofibrate or clofibrate.

Forty-one healthy male volunteers received 9 egg yolks daily in addition to their ordinary meals for 14 days. Mean elevation of serum cholesterollevels was 21,6 mg per 100 ml (11.4%) of the initial level. Middle-aged men (40 to 45) showed more elevation of serum cholesterollevel than young men (18 to 20). After the first egg yolk fee ding period, 6 young men and 3 middle-aged men, whose serum cholesterol levels increased by more than 10%, were selected to examine the etfect of moctamide on dietary hypercholesterolemia. They were given a daily oral dose of 300 mg of moctamide during the second egg yolk feeding period of 2 weeks, which was started 4 to 8 weeks after the end of the first period. In the third period, they were given 150 mg per day of moctamide in the same way. Daily doses of 300 mg of moctamide completely inhibited the elevation of serum cholesterol, while 150 mg suppressed it significantly.

Hepatic cholesterol 7α-hydroxylation and cholesterogenesis were determined in vitro at various time intervals 6 hr after oral or intravenous administration to fasted rats. Glucose administration to fasted rats enhanced cholesterol 7α-hydroxylation as well as fatty acid or cholesterol synthesis in the liver, though significant changes were not demonstrated in the cholesterol content of liver and serum throughout the observed periods. Hepatic cholesterol synthesis increased 1 hr after oral glucose ingestion. On the other hand, cholesterol 7α-hydroxylation was stimulated 2 hr after oral glucose administration, with a lag phase of 1 hr following the induction of cholesterol synthesis. From the results of the experiments on the effect of glucose ingestion, it appeared that cholesterol 7α-hydroxylation was correlated with hepatic cholesterogenesis. Hepatic cholesterogenesis was decreased in triparanol-treated rats and was not stimulated by glucose administration. Triparanol did not affect cholesterol hydroxylation in the fasted state, but did abolish the stimulatory effect of glucose. Short-term feeding of a high-cholesterol diet, which suppressed hepatic cholesterol synthesis, stimulated cholesterol 7α-hydroxylation. Oral administration of glucose to cholesterol-fed rats still further accelerated hydroxylation. In rats with ligated bile ducts, hepatic cholesterogenesis increased 24 hr after bileduct ligation while hydroxylation decreased 24 hr after the operation but was stimulated after 72 hr. Glucose ingestion by these rats stimulated both cholesterol synthesis and hydroxylation. It is concluded that increased hepatic cholesterogenesis enhances cholesterol 7α-hydroxylase activity; this activity does not depend upon increased fatty acid or other lipid synthesis, altered bile flow or gastrointestinal factors. Increased dietary cholesterol intake also accelerates hydroxylase activity. These mechanisms may preserve homeostasis in the serum cholesterol level, and an altered balance between these two enzyme systems — anabolic and catabolic — probably induces a change in the size of the body cholesterol pool.

Age-related changes in serum and liver cholesterol, phospholipid and triglyceride levels, serum lipoproteins, biliary secretion of cholesterol, phospholipids and bile acids, fecal excretion of sterols and bile acids, and the pool size of bile acids were examined in spontaneously hypertensive rats (SHR) and Wistar-Kyoto rats (WKR). SHR showed distinct age- and sex-related changes when young and marked aged-rat hypercholesterolemia after 1 yr of age. (1) Cholesterol shifted from blood to the liver between 10 and 20 wk only in male SHR and not at all in WKR. (2) Serum lipoprotein percentages changes; alpha-lipoprotein decreased, pre-beta-lipoprotein increased, but beta-lipoprotein did not change. These changes appeared only in male SHR and after 13 to 15 wk of age. (3) Liver enlargement in SHR, although not detected at 5 to 6 wk, progressed more rapidly than in WKR, giving values almost double those in WKR after 13 to 15 wk. Liver enlargement in female SHR was much less than in the male. (4) Bile flow, biliary secretion, and the pool size of bile acids increased. However, when expressed on the basis of liver weight, these values were similar to those in WKR, suggesting that the increases were caused by the hepatomegaly. (5) Differences appeared in the bile acid composition. A large amount of beta-muricholic acid was present in SHR of both sexes and the cholic acid percentage was low in male SHR. (6) Changes were observed in fecal bile acid excretion. Since the daily amounts in male SHR were similar to those in WKR, the hepatic synthesis activity (mg per day per 10 g liver) in male SHR was almost half that in WKR at all ages.

Thiobarbituric acid reactive substances (TBARS) in serum and hepatic subcellular organelles of rats were increased markedly after the feeding of a tocopherol deficient diet for 2–16 weeks. Although serum lipid concentrations from the rats fed the deficient diet for 2 weeks were significantly higher than those from the controls, there was no difference between the two groups after feeding for more than 4 weeks. However, a supplement of 2% cholesterol in these diets increased the serum cholesterol and phospholipid concentration in such tocopherol deficient rats. Refeeding of a tocopherol-rich diet to the deficient animals reduced the serum lipid concentrations concomitantly with the decrease of TBARS in serum and hepatic subcellular fractions. The tocopherol deficient animals showed lower synthetic activities of hepatic cholesterol and fatty acid as well as glucose-6-phosphatase in microsomes. These enzyme activities of cholesterol and fatty acid synthesis in the deficient animals tended to be restored by the tocopherol administration.

Changes of cholesterol, phospholipid, triglyceride or bile acid levels in serum liver, bile and feces after the treatment with alloxan were examined in Wistar strain male rats. Serum cholesterol, phospholipid and triglyceride levels and liver cholesterol level markedly increased but liver phospholipid and triglyceride levels remained unchanged. The lipid levels in serum very low density and low density lipoproteins were elevated but those in high density lipoprotein were not. Bile flow was not changed but biliary secretion of cholesterol, phospholipid and bile acids markedly increased. Among the biliary bile acid components, cholic acid markedly increased but the amount of chenodeoxycholic acid was similar to that of normal rats. Fecal excretion of deoxycholic acid increased but that of lithocholic and hyodeoxycholic acids decreased, and alpha, beta- and omega-muricholic acids did not change, thus, the total amount of fecal bile acids remained unchanged. Hepatic cholesterol synthesis was markedly depressed, while cholesterol 7 alpha-hydroxylase activity did not change and cytochrome P-450 content was elevated by about 40%. From such evidence, it was apparent that synthesis of cholic acid increased while that of chenodeoxycholic acid decreased and the total amount of bile acids synthesized did not change in the diabetic rats. Furthermore, marked increase of the pool size of cholic acid and hepatic secretion of cholic acid stimulated the absorption of lipids and produced a hyperlipidemia in the diabetic rats.

In either ad libitum or restricted feeding of the high cholesterol diet for 10 days, total plasma and liver cholesterol level of the diabetic rats were remarkably higher than those of the controls. The significant difference of the plasma cholesterol between control and diabetic rats was not observed in the groups fed the low cholesterol diet, while the liver cholesterol content was more in the diabetic rats than in the controls.The reduced biliary excretion of the total radioactivity in the diabetic rats was demonstrated using 4-14C cholesterol. Either the excretion of labeled cholic acid or cholesterol was also reduced in diabetic state, but the per cent of labeled cholesterol to total radioactivity in the bile of diabetic rats was larger than that of controls and the per cent of labeled cholic acid in the diabetic rats was less than that in controls.The production of expiratory CO2 following administration of 26-14C cholesterol in vivo was lower in the diabetic rats than controls, showing the decreased conversion rate of cholesterol to cholic acid in the diabetic rats.When labeled cholic acid was administered, excretion of the radioactivity from the bile fistula was not affected in diabetic rats and the conjugation pattern of the cholic acid with taurine and glycine was not altered. It suggests that the conjugation process of cholic acid with amino acid and excretion of cholic acid was little altered between control and diabetic rats.From these results it is concluded that the rapid progress of alimentary hypercholesteremia in the diabetic rats might be mainly accounted for the accumulation of cholesterol caused by the impairment of its conversion to cholic acid which delayed the excretion.

1. The influence of estradiol-17β on cortisol metabolism was studied in vitro using the rat liver homogenate and microsome fraction.2. It was found in the experiments using homogenates that β4-3-ketone reduction of cortisol was considerably increased following the addition of a given amount of estradiol-17β to the medium and this effect of estradiol-17β became more pronounced under an anaerobic condition or in the presence of potassium cyanide.3. The stimulatory action of estradiol-17β on cortisol metabolism and its relation to TPNH-generating system were investigated in the purified enzyme system (24, 000×g supernatant fraction). It was found that estradiol-17β was able to replace glucose-6-phosphate system and no effect of estradiol-17β was observed in the presence of TPNH. Similar stimulatory effect of estradiol-17β was noted on aldosterone metabolism.4. Experiments on estrogen metabolism in microsome fraction of the rat liver showed evidence that the addition of cortisol with TPN increased the production of estrone from estradiol-17β.5. The results obtained suggest that estradiol-17β acts as a hydrogen donor to TPN to increase the reduction of A-ring of cortisol.

1) One case of primary aldosteronism was reported. Adenoma of the left adrenal was confirmed on operation.2) In incubation experiments, overproduction of aldosterone and corticosterone was noted in the adenomatous tissue while cortisol and cortisone were produced only small amounts.3) The non-adenomatous tissue of the removed adrenal produced aldosterone about 1/3 the adenomatous tissue, although it produced more than normal adrenal tissue. The production of corticosterone, however, was very low.4) When corticosterone-4-C14 was added to an incubation medium with slices of adenoma, biosynthetic conversion of the radioactive steroid to aldosterone was greatly enhanced, 5 times as much as in the non-adenomatous tissue. Thus, an autonomous increase of the activity of 18-hydroxylase is reasonably considered.5) Histologically, hyperplasia was found in zona glomerulosa of the nonadenomatous portion of the removed adrenal cortex, suggesting some stimulating factor which continuously promotes a secretion of aldosterone. The pathogenesis of primary aldosteronism was discussed from a viewpoint of a renal stimulating factor.

Glucose-cysteine, hydroquinone, adrenaline, ascorbic acid, aspirin and butazolidin inhibit both the reduction of Δ4-3 ketone and the degradation of the side-chain in the metabolism of hydrocortisone in vitro.PAS and myleran inhibit only the degradation of the side-chain of hydrocortisone.