[Surfactant replacement therapy for respiratory distress syndrome: a pilot study]

A pilot study of the effect of exogenous surfactant (ES) on premature infants with respiratory distress syndrome (RDS) is reported. Each of the first 15 infants in this study received 200 mg/kg of natural surfactant (Curosurf) during the first day of life. Controls were 56 infants with RDS seen in the 15 months prior to the study. Within 5 minutes of starting ES, in all infants there was rapid and dramatic improvement in oxygenation and improvement in the average arterial/alveolar ratio of 169%. They had lower oxygen and ventilatory requirements than the control group throughout the first 5 days of life. No treated infant suffered from pulmonary air leak, while in the control group 21% developed pneumothorax and 11% had pulmonary interstitial emphysema. Mortality was 13% in the treated group as compared to 27% in the control group (p less than 0.01). There were no differences between the groups in the incidence of sepsis, patent ductus arteriosus, necrotizing enterocolitis, intraventricular hemorrhage, or bronchopulmonary dysplasia, nor were there side-effects of therapy. Dosage, timing and composition of the ideal surfactant are important questions for future studies.

Citrate and recurrent idiopathic calcium urolithiasis. A longitudinal pilot study on the metabolic effects of oral potassium citrate administered over the short-, medium- and long-term medication of male stone patients

In idiopathic recurrent calcium urolithiasis (RCU) in men (n = 37) the metabolic effects of oral tripotassium citrate (PC) were investigated in a longitudinal field study. The patients were either normo- (n = 22) or hypocitraturic (n = 15). Laboratory examinations were performed before, and after 3, 6, and more than 12 months of medication. Acceptance of PC was poor, mainly because of the salty taste of the tablet preparation chosen, and a number of participants dropped out of the study. In the remaining participants, compliance was acceptable when evaluated on the basis of urinary potassium and undesired side effects did not occur. In the short term (up to 3 months), PC evoked compensated metabolic alkalosis (pH and citrate in urine increased; blood gases remained normal), a drop in urinary calcium, together with increasing oxaluria, hydroxyapatite supersaturation, and calcium phosphate crystalluria. In the long term (greater than 12 months) PC urinary pH and citrate "dissociated", in that pH returned to pretreatment baseline values, whereas citrate stayed at high levels. In normocitraturics but not in hypocitraturics, urinary urea and sodium increased with PC. Hypocitraturics appeared to be less sensitive to the effects of PC, as reflected by the relatively small rise in urinary pH and citrate, and they maintained higher mean levels of indicators of bone metabolism (osteocalcin, alkaline phosphatase, hydroxyproline) despite continuous administration of PC. It was concluded that although the PC tablet preparation was effective it may not be an ideal anti-stone drug treatment in the long term and that, especially in hypocitraturics, the intrinsic metabolic defect of RCU may not be sufficiently well controlled.

Citrate and recurrent idiopathic calcium urolithiasis. A longitudinal pilot study on the metabolic effects of oral potassium sodium citrate administered as short-, medium- and long-term to male stone patients

In male patients with idiopathic recurrent calcium urolithiasis (RCU) the effects of oral potassium sodium citrate (PSC) on acid-base, citrate and mineral metabolism were investigated. There were 17 normocitraturic and 15 hypocitraturic patients. The examination time points in our clinical laboratory were prior to medication and after 3, 6 and over 12 months of medication. Urine collection periods were over 24 h, 2 h--after an overnight fast--3 h postprandially. Acceptance by the patients was poor, a large number refusing to take PSC for 12 months. Compliance of the patients continuing with the study was adequate as assessed by the urinary excretion of potassium and sodium. No unwanted side effects were observed. After 3 months of PSC medication a compensated metabolic alkalosis developed; in the urine calcium was decreased, while citrate, pH and oxalate were increased, as were hydroxyapatite supersaturation and calcium phosphate particles. After more than 12 months of PSC medication, citrate and pH tended toward the pretreatment baseline values, while hydroxyapatite supersaturation and calcium had already returned to pretreatment values. Despite ongoing PSC intake, patients with pre-existing hypocitraturia had lower urinary citrate than patients with previous normocitraturia, while the concomitant pH and hydroxyapatite supersaturation in the urine of the former remained at levels close to those of the latter. Under the influence of PSC, parathyroid gland function remained unchanged, but serum levels of bone alkaline phosphatase and osteocalcin were low, and urinary hydroxyproline was high.(ABSTRACT TRUNCATED AT 250 WORDS)

Maximal stimulation of pancreatic islet B-cells, and A-cell response to arginine, in dogs with longterm pancreatic acinar atrophy

The response of the pancreatic islet A- and B-cells after long-standing (eight years) pancreatic duct occlusion by prolamine, and subsequently developed acinar atrophy, was studied in five beagles, and the results compared with those in six sham-operated dogs. Intravenous arginine infusion (A-cell stimulation) and a combined oral glucose and intravenous tolbutamide and glucagon infusion (B-cell stimulation) were carried out in each dog. Complete abolition of acinar function after duct occlusion was documented by the negative paraaminobenzoic acid test. In contrast, in plasma, baseline values of glucose, alpha-amino-nitrogen, insulin, glucagon, glucagon-like immunoreactivity, somatostatin-like immunoreactivity, and pancreatic polypeptide did not differ between the experimental groups. During B-cell stimulation dogs with occluded ducts had significantly reduced insulin, reduced glucagon, and reduced second phase pancreatic polypeptide compared with controls. Integrated insulin and pancreatic polypeptide were also reduced in dogs with occluded ducts. In both groups plasma and integrated values of glucose and somatostatin-like immunoreactivity did not differ. During the A-cell stimulation period dogs with occluded ducts had significantly raised alpha-amino-nitrogen but unchanged glucose and reduced insulin concentrations; in both groups the arginine-induced rise in glucagon was similar, although it was delayed in the experimental group. In the latter, integrated alpha-amino-nitrogen was raised, but integrated glucose and hormones were unchanged. We conclude that a previously intact dog pancreas that has been atrophied by duct occlusion, may be able to maintain euglycaemia for several years. There may be a complex interplay of changes induced by duct occlusion at the level of the pancreatic islets and elsewhere, which compensate for moderate insulinopenia.

Structure and function of human jun-D

A jun related cDNA and its corresponding genomic fragment were cloned from human cells and sequenced. Polymerase chain reaction analysis showed that this gene is the human homologue of the mouse jun-D gene despite the fact that the degree of amino acid sequence conservation between the two is much poorer (77.3%) than that found between the homologues of c-jun and jun-B (95-98%). The product of this gene binds an AP-1 site and upon cotransfection stimulates the activity of a promoter that bears an AP-1 site. The level of activation is comparable to that of v-jun and the activity of both is further stimulated by v-fos. Deletion mutants of the gene that lack the best conserved region in the activating domain are poorly active. However, our data suggest that the activating domain is not confined exclusively to the conserved regions. Interestingly, at high concentrations human jun-D displays decreased activity which cannot be explained by a simple self squelching model.

Lambda Red-mediated synthesis of plasmid linear multimers in Escherichia coli K12

Expression of the red+ and gam+ genes of bacteriophage lambda in plasmids cloned in Escherichia coli wild-type cells leads to plasmid linear multimer (PLM) formation. In mutants that lack exonuclease I (sbcB sbcC), either of these lambda functions mediates PLM formation. In order to determine whether PLM formation in sbcB sbcC mutants occurs by conservative (break-join) recombination of circular plasmids or by de novo DNA synthesis, thyA sbcB sbcC mutants were transferred from thymine- to 5-bromo-2'-deoxyuridine (BUDR)-supplemented medium, concurrently with induction of red+ or gam+ expression, and the density distribution of plasmid molecular species was analyzed. After a period of less than one generation in the BUDR-supplemented medium, most PLM were of heavy/heavy density. Circular plasmids, as well as chromosomal DNA, were of light/light or light/heavy density. These results indicate that Red or Gam activities mediate de novo synthesis of PLM in sbcB sbcC mutants. Examination of plasmid DNA preparations from sbcB sbcC mutants expressing gam+ or red+ reveals the presence of two molecular species that may represent intermediates in the PLM biosynthesis pathway: single-branched circles (sigma-structures) and PLM with single-stranded DNA tails. While Gam-mediated PLM synthesis in sbcB mutants depends on the activity of the RecF pathway genes, Red-mediated PLM synthesis, like Red-mediated recombination, is independent of recA and recF activities. One of the red+ products, beta protein, suppresses RecA deficiency in plasmid recombination and PLM synthesis in RecBCD- ExoI- cells. The dependence of PLM synthesis on the RecE, RecF or Red recombination pathways and the dependence of plasmid recombination by these pathways on activities that are required for plasmid replication support the proposal that PLM synthesis and recombination by these pathways are mutually dependent. We propose the hypothesis that DNA double-stranded ends, which are produced in the process of PLM synthesis, are involved in plasmid recombination by the RecE, RecF and Red pathways. Conversely, recombination-dependent priming of DNA synthesis at 3' single-stranded DNA ends is hypothesized to initiate PLM synthesis on circular plasmid DNA templates.

A possible contribution of decrease in free fatty acids to low serum triglyceride levels after diets supplemented with n-6 and n-3 polyunsaturated fatty acids

Intraindividual comparisons of diets supplemented with sunflowerseed oil (rich in linoleic acid, LA, C18:2n-6), linseed oil (enriched with alpha-linolenic acid, LNA, C18:3n-3) and canned mackerel (rich in eicosapentaenoic acid, EPA, C20:5n-3 and docosahexaenoic acid, DHA, C22:6n-3) were made in 30 patients with primary hyperlipoproteinemia (HLP) of phenotypes IIa (n = 9), IIb (n = 7), IV (n = 7) and V (n = 7). The lipid- and blood pressure-lowering effects of polyunsaturated fatty acids (PUFA), particularly those of the EPA- and DHA-rich diet, were confirmed irrespective of the type of HLP. Apolipoproteins A-I and B remained unchanged. The most remarkable finding was a substantial depression of free fatty acids (FFA) within a standardized glucose tolerance test (GTT) associated with the fall of serum triglycerides after diets enriched with n-6 and especially after those supplemented with n-3 PUFA. It was suggested that the decrease of FFA indicates reduced peripheral lipolysis, which might be a hitherto ignored factor involved in the triglyceride-lowering action of n-6 and, more pronounced, of n-3 PUFA.

[Serum enzymes in grade I hypertensive patients before and following a change in nutrition in relation to polyene acid and electrolyte content]

In patients with mild hypertension the blood pressure reduction through n-3 fatty acids can be improved by an additional increase of the potassium intake. Metabolic processes can be followed up by determinating serum enzymes. By an additional daily intake of 200 g fish for 14 days the metabolism is hardly changed. The increased activity of the transaminases after diet is probably a consequence of the increased protein intake.

Effects of dietary oleic, linoleic and alpha-linolenic acids on blood pressure, serum lipids, lipoproteins and the formation of eicosanoid precursors in patients with mild essential hypertension

Forty-four male in-patients with mild essential hypertension were randomly allocated to three groups and put on diets supplemented with 60 ml/day of olive (n = 15), sunflowerseed (n = 15) or linseed oils (n = 14), respectively, for two weeks within a blind study. In the group receiving sunflowerseed oil an increase of linoleic acid in serum lipids could be observed, whereas arachidonic and eicosapentaenoic acids appeared unchanged in serum triglycerides and even significantly lower in cholesterol esters. The subjects ingesting the linseed oil-rich diet showed an increase of alpha-linolenic acid in serum lipids, whereas arachidonic and eicosapentaenoic acids remained unchanged in serum triglycerides. In cholesterol esters, however, arachidonic acid was significantly decreased and eicosapentaenoic acid appeared increased only to a low level of significance. In the group put on the olive oil-rich regimen only a significant fall of linoleic acid was obvious in serum triglycerides. The results might indicate a defective desaturation and elongation of linoleic and alpha-linolenic acids and, consequently, a slow formation of arachidonic and eicosapentaenoic acids in patients with mild essential hypertension, which should be considered in dietary studies. After the sunflowerseed oil-rich diet a significant decrease of total cholesterol, low density lipoprotein (LDL) cholesterol and the LDL/high density lipoprotein (HDL) cholesterol ratio was found. Systolic blood pressure during a psychophysiological stress test and urinary sodium excretion appeared significantly lower after the linoleic acid-rich diet. After the linseed oil-rich diet, in addition to total cholesterol, LDL cholesterol and the LDL/HDL cholesterol ratio, serum triglycerides and lecithin cholesterol acyl transferase (LCAT) activity were significantly depressed.(ABSTRACT TRUNCATED AT 250 WORDS)

Blood pressure and serum lipids from SHR after diets supplemented with evening primrose, sunflowerseed or fish oil

Spontaneously hypertensive rats (SHR) at 4 weeks of age were fed a diet supplemented with sunflowerseed oil (SO), evening primrose oil (EPO), fish oil (FO) or EPO + FO for 22 weeks. A diet with commercially available pellets served as control. Systolic blood pressure was significantly lower during and after FO, EPO and EPO + FO, whereas the lower level after SO was not significant when compared with the controls. Serum triglycerides and total cholesterol were lowest after EPO followed FO. The combination of both EPO and FO resulted in unexpected high values of triglycerides and cholesterol. HDL-cholesterol was likewise highest after EPO + FO. The results indicate a quantitatively different depression of blood pressure and serum lipids from SHR by individual polyunsaturated fatty acids (PUFA).

Extreme decrease of linoleic acid in renal medulla from rats after a diet supplemented with cod liver oil

Spontaneously hypertensive (SHR) and normotensive rats were fed a diet supplemented with linseed oil or cod liver oil for 22 weeks. The most remarkable finding was an extreme fall of linoleic acid in lipids from renal medulla after cod liver oil supplementation. In free fatty acids (FFA) eicosatrienoic acid (C2): 3n-9) appeared increased as a sign of essential fatty acid (EFA) deficiency.

N-6 and N-3 PUFA in liver lipids, thromboxane formation and blood pressure from SHR during diets supplemented with evening primrose, sunflowerseed or fish oil

Spontaneously hypertensive rats (SHR) after weaning (at 4 weeks of age) were fed diets supplemented with either sunflowerseed oil (SO), evening primrose oil (EPO), fish oil (FO) or EPO + FO (50%: 50%, v/v) for 22 weeks. A diet with commercially available pellets served as control. Systolic blood pressure was significantly lower in the dietary groups receiving FO, EPO and FO + EPO, the former being most effective. In liver triglycerides (TG) EPO resulted in a markedly increased percentage of linoleic acid (LA; C 18:2, n-6), alpha-linolenic acid (alpha-LNA; C 18:3, n-6) and especially of arachidonic acid (AA; C 20:4, n-6), whereas the long-chain n-3 polyunsaturated fatty acids (PUFA), eicosapentaenoic acid (EPA; C 20:5, n-3) and docosahexaenoic acid (DHA; C 22:6 n-3), were depressed to undetectable and significantly lower levels, respectively. In liver phosphatidylcholine (PC) and phosphatidylethanolamine (PE) only slight changes of LA and AA were observed. Feeding of FO led to a significant rise of EPA and DHA in liver TG, PC and PE at the expense of n-6 PUFA (except LA in PC and PE). With a combination of both EPO and FO a significant increase of EPA and DHA, but on lower levels as compared to FO alone, was associated with a significant rise of LA, but with a slight decline of AA as compared to the control animals. Nevertheless, the levels of AA in the group fed EPO + FO were still higher than in the FO-group. In the SO-group the increase of LA was even higher when compared with the EPO-group.(ABSTRACT TRUNCATED AT 250 WORDS)

Suppression of recA deficiency in plasmid recombination by bacteriophage lambda beta protein in RecBCD- ExoI- Escherichia coli cells

Plasmid recombination, like other homologous recombination in Escherichia coli, requires RecA protein in most conditions. We have found that the plasmid recombination defect in a recA mutant can be efficiently suppressed by the beta protein of bacteriophage lambda. beta protein is required for homologous recombination of lambda chromosomes during lytic phage growth in a recA host and is known to have a strand-annealing activity resembling that of RecA protein. The bioluminescence recombination assay was used for genetic analysis of beta-protein-mediated plasmid recombination. Efficient suppression of the recA mutation by beta protein required the absence of the E. coli nucleases exonuclease I and RecBCD nuclease. These nucleases inhibit a RecA-mediated plasmid recombination pathway that is more efficient than the pathway functioning in wild-type cells. Like RecA-mediated plasmid recombination in RecBCD- ExoI- cells, beta-protein-mediated plasmid recombination depended on concurrent DNA replication and on the activity of the recQ gene. However, unlike RecA-mediated plasmid recombination, beta-protein-mediated recombination in RecBCD- ExoI- cells was independent of recF and recJ activities. We propose that inactivation of exonuclease I and RecBCD nuclease stabilizes a recombination intermediate that is involved in RecA- and beta-protein-catalyzed homologous pairing reactions. We suggest that the intermediate may be linear plasmid DNA with a protruding 3' end, since these nucleases are known to interfere with the synthesis of such linear forms. The different recF and recJ requirements for beta-protein-dependent and RecA-dependent recombinations imply that the mechanisms of formation or processing of the putative intermediate differ in the two cases.

Cellular factors that interact with the hepatitis B virus enhancer

An 83-base-pair-long hepatitis B virus DNA fragment efficiently activates the transcription of the heterologous globin gene promoter. This fragment contains binding sites for at least four distinct cellular factors termed E, TGT3, EP, and NF-I. E is a positively acting factor, responsive to phorbol ester. EP is apparently identical to the factor EF-C that binds to the polyomavirus enhancer. The conservation of the binding site sequences for most of these factors in the genomes of other members of the hepadnavirus family suggests that these viruses share common enhancer elements.

Improvement of oral glucose tolerance in the dog by feeding trypsin inhibitor. Role of the enteroinsular axis

The influence of oral trypsin inhibitor (TI) or vehicle (V) during 4 weeks on oral glucose tolerance (OGT) and on the enteroinsular axis (EIA) of insulin, CCK, and gastrin was studied in five beagles. TI improved OGT throughout the 180-min test period. Incremental areas of insulin and gastrin did not differ from 0 to 60 min after TI and V treatment, but both increased significantly from 60 to 180 min after TI. From 0 to 60 min CCK decreased significantly in the TI group, whereas the differences (delta) in hormone changes (insulin, CCK, gastrin) observed during oral and intravenous glucose showed a decrease for their incremental areas during this period. During the 60- to 180-min period this hormone spectrum was reversed into a non-significant increase. We suggest that TI pretreatment improves oral glucose tolerance, possibly owing to decreased intestinal glucose absorption (early test period), augmentation of the incretin effect (later test period), or some unidentified factor.

Acute glomerulonephritis secondary to lobar pneumonia

We report 4 cases of children who developed lobar pneumonia and subsequently acute glomerulonephritis, all within a period of six weeks. In one case streptococcus pneumonia type 5 was isolated, a strain not previously described in the literature as being nephritogenic.

Changes of N-6 and N-3 fatty acids in liver from spontaneously hypertensive (SHR) and normotensive rats after diets supplemented with alpha-linolenic or eicosapentaenoic acids

In spontaneously hypertensive (SHR) and normotensive rats (WKY), diets supplemented with n-3 fatty acids of different chain length (alpha-linolenic acid, LNA-C 18:3, n-3 with linseed oil and eicosapentaenoic acid, EPA-C 20:5, n-3 with cod liver oil) were fed over a period of 22 weeks. A diet with commercially available pellets served as control. After the LNA-rich diet the augmentation of LNA was most pronounced in liver triglycerides (TG) and free fatty acids (FFA), whereas the increase of EPA was most marked in phosphatidylethanolamine (PE) and phosphatidylcholine (PC) when compared with the controls. Docosahexaenoic acid (DHA) was decreased mainly in neutral lipids. Of the n-6 fatty acids linoleic acid (LA) appeared significantly depressed in TG and FFA, but increased in phospholipids. Arachidonic acid (AA), however, was lower in all lipids. In SHR and WKY fed the EPA-rich diet EPA and DHA were significantly higher as compared to the controls on a pellet diet. On the contrary, LNA was not detectable in all lipid classes. LA and AA were markedly depressed. Docosenoic acids were significantly increased. The p/s-ratio did not reflect the changes in the 20:5/20:4- and n-3/n-6-ratios. The data indicate a differential effect of dietary n-3 fatty acids of different chain length on the supply of other n-3 fatty acids. Moreover, after an LNA-rich diet divergent alterations of LA in neutral lipids and phospholipids occurred. The results are dissimilar to those obtained in adipose tissue. Blood pressure was not influenced by the diets in either SHR or WKY.

Integration of hepatitis B virus: analysis of unoccupied sites

Hepatitis B virus (HBV) sequences integrated in the PLC/PRF/5 cell line (Alexander cells), which was derived from a human primary liver carcinoma, were previously extensively studied. Here we describe the analysis of the unoccupied sites of two linearly integrated forms of HBV DNA, AL-14 and AL-26, that were characterized previously. No major cellular DNA rearrangements were seen at the integration sites except for small deletions of host sequences: 2 kilobases of DNA in AL-14 and 17 base pairs (bp) in AL-26. The unoccupied site of AL-26 was found to be missing 182 bp, which previously mapped next to the right end of the integration sites of several independent clones. These were believed to be of cellular origin, but we show here that these 182 bp are in fact from unusual HBV sequences. Surprisingly, a region of this newly detected HBV DNA sequence is more homologous to that of woodchuck HBV DNA. Our analysis shows that the normal counterparts of both AL-14 and AL-26 contain minisatellite-like repetitive sequences. Based on the data presented here and our previous finding of HBV DNA integration at satellite sequences, we propose that genomic simple repetitive sequences are hot spots for HBV DNA integration.

Long-term effect of mackerel diet on blood pressure, serum lipids and thromboxane formation in patients with mild essential hypertension

Twelve male patients with mild essential hypertension were put on a diet supplemented with 2 cans of mackerel/day (= 2.2 g daily of eicosapentaenoic acid, EPA, C20:5 n-3 and 2.8 g daily of docosahexaenoic acid, DHA, C22:6 n-3) for 2 weeks within an isocaloric regimen and then with 3 cans/week (= 3.3 g/week, equivalent to 0.47 g daily of EPA and 4.2 g/week, equivalent to 0.69 g daily of DHA) for 8 months with a subsequent period of 2 months on normal diet. Eleven male hypertensives matched for age, body weight index, blood pressure and serum lipids with no change in their nutritional habits served as controls. After the first dietary period (2 weeks) a significant decrease of serum triglycerides (TG), total and LDL-cholesterol, blood pressure and thromboxane B2 (TxB2) was found, whereas HDL cholesterol and potassium in erythrocytes were significantly increased. During the second dietary period (8 months) providing the lower dose of EPA, serum lipids and the other biochemical parameters returned to the initial values. Blood pressure, however, remained significantly lower and rose to the basal levels only after the third period (2 months) on normal diet. In the control group no alterations could be seen. The data suggest a dose-related differential effect of dietary EPA on serum lipids, lipoproteins, TxB2 and blood pressure in subjects with mild hypertension.

Different changes of n-6 and n-3 fatty acids in adipose tissue from spontaneously hypertensive (SHR) and normotensive rats after diets supplemented with linolenic or eicosapentaenoic acids

In spontaneously hypertensive (SHR) and normotensive rats of the Wistar-Kyoto (WKY) and Wistar-Schönwalde (WSCHOE) strain, diets supplemented with n-3 fatty acids of different chain length (alpha-linolenic acid, LNA--C 18:3, n-3 with linseed oil and eicosapentaenoic acid, EPA--C 20:5, n-3 with cod liver oil) were fed over a period of 22 weeks. After the LNA-rich diet, among the long-chain n-3 fatty acids EPA in epididymal adipose tissue remained unchanged, whereas docosapentaenoic (DPA) and docosahexaenoic acids (DHA) fell. The n-6 fatty acids linoleic (LA) and arachidonic acid (AA) both appeared decreased. After the EPA-rich diet, all n-3 fatty acids, i.e. not only EPA, DPA and DHA, but also LNA were augmented when compared with controls fed commercially available pellets. Among the n-6 fatty acids LA was extremely depressed, whereas AA appeared increased. The p/s-ratio was elevated after the LNA-rich diet, but decreased after the EPA-rich diet. The data indicate a differential effect of dietary n-3 fatty acids of different chain length on the supply of other n-3 fatty acids, of LA and AA as well as on the p/s-ratio in adipose tissue of rats. Blood pressure was not influenced by either diet in either SHR or in both normotensive strains of rats.

Slow desaturation and elongation of linoleic and alpha-linolenic acids as a rationale of eicosapentaenoic acid-rich diet to lower blood pressure and serum lipids in normal, hypertensive and hyperlipemic subjects

In normal, hypertensive and hyperlipemic subjects, diets supplemented with linoleic acid (LA) or alpha-linolenic acid (LNA) resulted in an increase of the corresponding fatty acids in serum lipids. However, their C20-derivatives, the prostaglandin precursors arachidonic acid (AA) and eicosapentaenoic acid (EPA), respectively, were not or only slightly augmented. On the other hand, an EPA-rich diet produced a marked increase of this fatty acid, especially in cholesterol esters. After this diet the decreases of blood pressure and serum lipids were more pronounced when compared with LA- and LNA-rich diets containing a 20-fold higher dose of the polyunsaturated fatty acids. The slow formation of AA and EPA from LA and LNA seems to be a characteristic finding in humans, being different from preferred laboratory animals, for instance, rats. This observation was independent of the presence of risk factors, like arterial hypertension or hyperlipoproteinemia (HLP).

Blood pressure- and lipid-lowering effect of mackerel and herring diet in patients with mild essential hypertension

Fourteen male patients with mild essential hypertension were put on a mackerel and herring diet within a prescribed isocaloric regimen in a cross-over design for 2 weeks. After mackerel diet eicosapentaenoic acid (EPA-C20:5, n-3) appeared more in cholesterol esters (1.7-11.0%), whereas docosahexaenoic acid (DHA-C22:6, n-3) was predominantly incorporated into serum triglycerides (1.0-8.3%). After herring diet, which contained half as much EPA and DHA, their increase was of minor degree. After mackerel diet serum triglycerides, total cholesterol, LDL cholesterol and lecithin cholesterol acyl transferase (LCAT) activity were significantly decreased (by 28%, 9%, 14% and 14%, respectively), returning to the initial levels 3 months later. On the contrary, HDL cholesterol appeared significantly increased (by 12%). After herring diet the differences were not significant. Serum sodium was significantly lower (by 2%) at the end of the mackerel diet as compared to the initial values. On the other hand, uric acid in serum appeared transiently increased (by 24%) at the end of both dietary periods. A significant decrease (by 8%) in casual systolic blood pressure, measured in recumbent position, could be observed only at the end of the mackerel period. Moreover, the level of systolic and diastolic blood pressure before and during a standardized psychophysiological stress test was significantly lower after mackerel diet. Nevertheless, the increments after stress were similar. Plasma renin activity was increased (by 64%) after mackerel diet.(ABSTRACT TRUNCATED AT 250 WORDS)