The extent and duration of postprandial lipaemia have been linked to risk of CHD but the influence of dietary variables on, and the relative contributions of, exogenous (chylomicron) and endogenous (VLDL) triacylglycerols to the total lipaemic response have not been comprehensively evaluated. In the present study the triacylglycerol, apolipoprotein (apo) B-48 and retinyl ester (RE) responses to three test meals of varying monounsaturated (MUFA) and saturated fatty acid (SFA) content were measured in the triacylglycerol-rich lipoprotein (TRL) fraction of plasma (rho = 1.006 g/ml) for 9 h after meal consumption. Fifteen healthy normolipidaemic young men consumed, on separate occasions, three test meals which were identical apart from their MUFA and SFA contents. Expressed as a percentage of total energy the MUFA/SFA contents of the meals were: (1) 12 %/17 %; (2) 17 %/12 % and (3) 24 %/5 %. The contribution of the intestinally-derived lipoproteins (chylomicrons) to the lipaemic response was investigated by determining the time to reach peak concentration and the total and incremental areas under the time response curves (AUC and incremental AUC) for RE, apoB-48 and triacylglycerol in the TRL fraction. No significant differences in these measurements were observed for the three meals. However, visual comparison of the postprandial responses to the three meals suggested that as meal MUFA content increased there was a tendency for the triacylglycerol, apoB-48 and RE responses to become biphasic as opposed to the typical monophasic response seen with the 12 % MUFA/17 % SFA meal. Comparison of the apoB-48 and RE responses for the three test meals confirmed other workers' findings of delayed entry of RE relative to apoB-48 in TRL. The value of the two markers in investigating dietary fat absorption and metabolism is discussed.

In two separate studies, the cholesterol-lowering efficacy of a diet high in monounsaturated fatty acids (MUFA) was evaluated by means of a randomized crossover trial. In both studies subjects were randomized to receive either a high-MUFA diet or the control diet first, which they followed for a period of 8 weeks; following a washout period of 4–6 weeks they were transferred onto the opposing diet for a further period of 8 weeks. In one study subjects were healthy middle-aged men (n30), and in the other they were young men (n23) with a family history of CHD recruited from two centres (Guildford and Dublin). The two studies were conducted over the same time period using identical foods and study designs. Subjects consumed 38 % energy as fat, with 18 % energy as MUFA and 10 % as saturated fatty acids (MUFA diet), or 13 % energy as MUFA and 16 % as saturated fatty acids (control diet). The polyunsaturated fatty acid content of each diet was 7 %. The diets were achieved by providing subjects with manufactured foods such as spreads, ‘ready meals’, biscuits, puddings and breads, which, apart from their fatty acid compositions, were identical for both diets. Subjects were blind to which of the diets they were following on both arms of the study. Weight changes on the diets were less than 1 kg. In the groups combined (n53) mean total and LDL-cholesterol levels were significantly lower at the end of the MUFA diet than the control diet by 0·29 (sd 0·61) mmol/l (P< 0·001) and 0·38 (sd 0·64) mmol/l (P< 0·0001) respectively. In middle-aged men these differences were due to a mean reduction in LDL-cholesterol of – 11 (sd 12) % on the MUFA diet with no change on the control diet (−1·1 (sd 10) %). In young men the differences were due to an increase in LDL-cholesterol concentration on the control diet of +6·2 (sd 13) % and a decrease on the MUFA diet of −7·8 (sd 20) %. Differences in the responses of middle-aged and young men to the two diets did not appear to be due to differences in their habitual baseline diets which were generally similar, but appeared to reflect the lower baseline cholesterol concentrations in the younger men. There was a moderately strong and statistically significant inverse correlation between the change in LDL-cholesterol concentration on each diet and the baseline fasting LDL-cholesterol concentration (r– 0·49;P< 0·0005). In conclusion, diets in which saturated fat is partially replaced by MUFA can achieve significant reductions in total and LDL-cholesterol concentrations, even when total fat and energy intakes are maintained. The dietary approach used to alter fatty acid intakes would be appropriate for achieving reductions in saturated fat intakes in whole populations.

Postprandial lipaemic responses to two test meals were investigated in 30 Northern (15 British and 15 Irish), and 30 Southern (Greeks from Crete) healthy male Europeans. The meals were a saturated fatty acid (SFA) meal, which resembled the fatty acid composition of an average UK diet, and a monounsaturated fatty acid (MUFA) meal in which the fat consisted of olive oil. Habitual diets of the two groups differed, with higher total fat, (P<0.03) and MUFA (P<0.0001) and lower polyunsaturated fatty acid (PUFA) (P<0.0001) intakes in Southern than Northern Europeans. Levels of total MUFA (P<0.02) and oleic acid (P<0.004) were also higher in adipose tissue of Southern in comparison to Northern Europeans. In both European groups there were no significant differences in postprandial triglyceride response between the two meal types, SFA or MUFA. However, Northern and Southern Europeans showed significant differences in their patterns of postprandial response in plasma triglycerides (P<0.0001), apolipoprotein B-48 (P<0.0001), NEFA (P<0.0001), insulin (P<0.0007), and factor VII activity (P0.03). In the case of NEFA, areas under the response curve were higher following the SFA than the MUFA meal for both groups, (P<0.003) and were greater in Southern than Northern Europeans (P<0.002) and apo B-48 responses were lower (P<0.005). Some of these differences may reflect differences in fasting levels since fasting apolipoprotein B-48 levels were lower (P<0.01) and fasting NEFA (P<0.02) and insulin (P<0.005) were higher in the Southern than in the Northern Europeans. In addition, 9 h postprandial post-heparin lipoprotein lipase activity was lower in the Southern than in the Northern Europeans (P<0.0006). This is the first report of differences in postprandial lipid, factor VII and insulin responses in Southern and Northern Europeans which may be of importance in explaining the different susceptibilities of these two populations to risk of coronary artery disease.

Conference Abstract| July 01 1995 Bezafibrate Reduces Chylomicron Synthesis and Postprandial Lipaemia in Non-Insulin Dependent Diabetes Mellitus S Sethi; S Sethi 1School of Biological Sciences, University of Surrey, Guildford, Surrey GU2 5XH, U.K. Search for other works by this author on: This Site PubMed Google Scholar J Lovegrove; J Lovegrove 1School of Biological Sciences, University of Surrey, Guildford, Surrey GU2 5XH, U.K. Search for other works by this author on: This Site PubMed Google Scholar MC Murphy; MC Murphy 1School of Biological Sciences, University of Surrey, Guildford, Surrey GU2 5XH, U.K. Search for other works by this author on: This Site PubMed Google Scholar BJ Gould; BJ Gould 1School of Biological Sciences, University of Surrey, Guildford, Surrey GU2 5XH, U.K. Search for other works by this author on: This Site PubMed Google Scholar CM Williams; CM Williams 1School of Biological Sciences, University of Surrey, Guildford, Surrey GU2 5XH, U.K. Search for other works by this author on: This Site PubMed Google Scholar J Wright J Wright 1School of Biological Sciences, University of Surrey, Guildford, Surrey GU2 5XH, U.K. Search for other works by this author on: This Site PubMed Google Scholar Clin Sci (Lond) (1995) 89 (s33): 8P–9P. https://doi.org/10.1042/cs089008Pc Views Icon Views Article contents Figures & tables Video Audio Supplementary Data Peer Review Share Icon Share Facebook Twitter LinkedIn MailTo Cite Icon Cite Get Permissions Citation S Sethi, J Lovegrove, MC Murphy, BJ Gould, CM Williams, J Wright; Bezafibrate Reduces Chylomicron Synthesis and Postprandial Lipaemia in Non-Insulin Dependent Diabetes Mellitus. Clin Sci (Lond) 1 July 1995; 89 (s33): 8P–9P. doi: https://doi.org/10.1042/cs089008Pc Download citation file: Ris (Zotero) Reference Manager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search Search Dropdown Menu toolbar search search input Search input auto suggest filter your search All ContentAll JournalsClinical Science Search Advanced Search This content is only available as a PDF. © 1995 The Biochemical Society and the Medical Research Society1995 Article PDF first page preview Close Modal You do not currently have access to this content.

OBJECTIVE:The present study was carried out to determine effects of test meals of different fatty acid compositions on postprandial lipoprotein and apolipoprotein metabolism.DESIGN:The study was a randomized, single blind design.SETTING:The study was carried out in the Clinical Investigation Unit of the Royal Surrey County Hospital.SUBJECTS:Twelve male normal subjects with an average age of 22.4 +/- 1.4 years (mean +/- SD) were selected from the student population of the University of Surrey; one subject dropped out of the study because he found the test meal unpalatable.INTERVENTIONS:The subjects were given three evening test meals on three separate occasions, in which the oils used were either a mixed oil (rich in saturated fatty acids and approximated the fatty acid intake of the current UK diet), corn oil (rich in n-6 fatty acids), or fish oil (rich in n-3 fatty acids) 40 g of the oil under investigation were incorporated into a rice-based test meal. Triacylglycerol-rich lipoproteins-triacylglycerol (TRL-TAG), TRL-cholesterol (TRL-cholesterol), plasma-TAG, plasma cholesterol (T-C), and serum apolipoprotein A-I and B (apo A-I and B) responses were measured. Postprandial responses were followed for 11 h.RESULTS:Postprandial plasma-TAG responses, calculated as incremental areas under the response curves (IAUC) were significantly reduced following the fish oil meal [365.5 +/- 145.4 mmol/l x min (mean +/- SD)[ compared with the mixed oil meal (552.0 +/- 141.7 mmol/l x min) (P < 0.05) and there was a strong trend towards the same direction in the TRL-TAG responses. In all instances, plasma-and TRL-TAG showed a biphasic response with increased concentrations occurring at 1h and between 3 and 7h postprandially. TRL-cholesterol, T-C, and serum apo A-I and B responses to the three meals were similar.CONCLUSIONS:The findings support the view that fish oils decrease postprandial lipaemia and this may be an important aspect of their beneficial effects in reducing risk of coronary heart disease (CHD). Further work is required to determine the mechanisms responsible for this effect.

The present study has examined the possibility that the positional distribution of fatty acids on dietary triacylglycerol (TAG) influences the postprandial response to a liquid meal in adult subjects. Postprandial TAG, non-esterified fatty acids (NEFA), ketones, glucose, insulin and gastric inhibitory polypeptide (GIP) responses were monitored in sixteen normal adult male subjects over 6 h following consumption of test meals containing dietary TAG in which palmitic acid was predominantly on the sn-1 (Control) or sn-2 positions (Betapol). Plasma total TAG, chylomicron-rich TAG and chylomicron-poor TAG concentrations were identical in response to the two test meals. The peak increase (mean (SD)) in chylomicron TAG was 0.85 (0.46) mmol/l after the Control meal and 0.85 (0.42) mmol/l after the Betapol meal. Plasma glucose, insulin, GIP, NEFA and ketone concentrations were also very similar following the two meals. It is concluded that dietary TAG containing saturated fatty acids on the sn-2 position appear in plasma at a similar level and over a similar timescale to TAG in which saturated fatty acids are predominantly located on sn-1 or sn-3 positions. The results reported in the present study demonstrate that the positional distribution of fatty acids on dietary TAG is not an important determinant of postprandial lipaemia in adult male subjects, but do not exclude the possibility that different responses may occur when these dietary TAG are given long term.

The effect of cereal source and processing on postprandial glycaemic and insulinaemic responses to test meals of commercially-available cereal products was investigated in two groups of six healthy, non-obese volunteers. The first study investigated the possible effect of different cereal sources used to make bread. Portions of a wholemeal wheat bread containing 50 g carbohydrate were compared with portions of bread containing either 20% oat flour or 50% rye, selected on the basis of similar processing and composition except for cereal source and containing an equivalent amount of carbohydrate. The second study investigated the effect of different processing on cereal starch from one source. Portions of three wheat-based breakfast cereals, processed by puffing, flaking or shredding and containing 50 g carbohydrate were compared. In the first study no significant differences were found in the postprandial incremental responses (0–180 min) between the breads for either glucose, insulin or the insulin-stimulating gastrointestinal hormone glucose-dependent insulinotropic polypeptide (GIP). In the second study, the incremental responses (0–180 min) for glucose and insulin were significantly lower following consumption of puffed wheat compared with shredded wheat. There were no significant differences in postprandial GIP responses between the three breakfast cereals. We conclude that substitution of starches from different cereal sources in commercially available bread is without effect on glucose tolerance and insulin secretion. Processing in wheat-starch breakfast cereals did influence glucose tolerance and insulin secretion, but the effect was small. It appears that the starch processing undergone in the production of commercially-available breads and breakfast cereals is severe enough to render the starch readily digestible, regardless of cereal source and processing used, thus minimising any differences in metabolic responses.

Conference Article| May 01 1993 The use of retinyl palmitate to measure clearance of chylomicrons and chylomicron remnants following meals of different fatty acid compositions ANTONIOS ZAMPELAS; ANTONIOS ZAMPELAS 1The Nutritional Metabolism Research Group, School of Biological Sciences, University of Surrey, Guildford GU2 5XH Search for other works by this author on: This Site PubMed Google Scholar ERIC AH-SING; ERIC AH-SING 1The Nutritional Metabolism Research Group, School of Biological Sciences, University of Surrey, Guildford GU2 5XH Search for other works by this author on: This Site PubMed Google Scholar JAGADISH CHAKRABORATY; JAGADISH CHAKRABORATY 1The Nutritional Metabolism Research Group, School of Biological Sciences, University of Surrey, Guildford GU2 5XH Search for other works by this author on: This Site PubMed Google Scholar MARGARET MURPHY; MARGARET MURPHY 1The Nutritional Metabolism Research Group, School of Biological Sciences, University of Surrey, Guildford GU2 5XH Search for other works by this author on: This Site PubMed Google Scholar ANDREW PEEL; ANDREW PEEL 1The Nutritional Metabolism Research Group, School of Biological Sciences, University of Surrey, Guildford GU2 5XH Search for other works by this author on: This Site PubMed Google Scholar JOHN WRIGHT; JOHN WRIGHT 1The Nutritional Metabolism Research Group, School of Biological Sciences, University of Surrey, Guildford GU2 5XH Search for other works by this author on: This Site PubMed Google Scholar CHRISTINE M. WILLIAMS CHRISTINE M. WILLIAMS 1The Nutritional Metabolism Research Group, School of Biological Sciences, University of Surrey, Guildford GU2 5XH Search for other works by this author on: This Site PubMed Google Scholar Biochem Soc Trans (1993) 21 (2): 137S. https://doi.org/10.1042/bst021137s Views Icon Views Article contents Figures & tables Video Audio Supplementary Data Peer Review Share Icon Share Twitter LinkedIn Cite Icon Cite Get Permissions Citation ANTONIOS ZAMPELAS, ERIC AH-SING, JAGADISH CHAKRABORATY, MARGARET MURPHY, ANDREW PEEL, JOHN WRIGHT, CHRISTINE M. WILLIAMS; The use of retinyl palmitate to measure clearance of chylomicrons and chylomicron remnants following meals of different fatty acid compositions. Biochem Soc Trans 1 May 1993; 21 (2): 137S. doi: https://doi.org/10.1042/bst021137s Download citation file: Ris (Zotero) Reference Manager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search Search nav search search input Search input auto suggest search filter All ContentAll JournalsBiochemical Society Transactions Search Advanced Search This content is only available as a PDF. © 1993 Biochemical Society1993 Article PDF first page preview Close Modal You do not currently have access to this content.

The acute effects of different macronutrients on the secretion of glucagon-like peptide-1(7-36)amide (GLP-1(7-36)amide) and glucose-dependent insulinotropic polypeptide (GIP) were compared in healthy human subjects. Circulating levels of the two hormones were measured over a 24-h period during which subjects consumed a mixed diet. In the first study, eight subjects consumed three equicaloric (375 kcal) test meals of carbohydrate, fat and protein. Small increases in plasma GLP-1(7-36) amide were found after all meals. Levels reached a maximum 30 min after the carbohydrate and 150 min after the fat load. Ingestion of both carbohydrate and fat induced substantial rises in GIP secretion, but the protein meal had no effect. In a second study, eight subjects consumed 75 g glucose or the equivalent portion of complex carbohydrate as boiled brown rice or barley. Plasma GIP, insulin and glucose levels increased after all three meals, the largest increase being observed following glucose and the smallest following the barley meal. Plasma GLP-1(7-36)amide levels rose only following the glucose meal. In the 24-h study, plasma GLP-1(7-36)amide and GIP concentrations were increased following every meal and remained elevated throughout the day, only falling to fasting levels at night. The increases in circulating GLP-1(7-36)amide and GIP levels following carbohydrate or a mixed meal are consistent with their role as incretins. The more sustained rises observed in the daytime during the 24-h study are consistent with an anabolic role in lipid metabolism.

The present study reports results from two investigations to determine effects of a 6-week period of moderaten-3 fatty acid supplementation (2.7 g/d) on fasting and on postprandial triacylglycerol and metabolic hormone concentrations in response to standard test meals. In the first study postprandial responses were followed for 210 min after an early morning test meal challenge; in the second study responses to an evening test meal were followed during the evening and overnight for a total period of 12 h. In both studies postprandial triacylglycerol responses to the test meals were significantly reduced after compared with before fish-oil supplementation. In the second study the triacylglycerol peak response seen between 200 and 400 min in subjects studied before supplementation with fish oils was almost completely absent in the same subjects after 6 weeks ofn-3 fatty acid supplementation. Analysis of fasting concentrations of metabolites and hormones was carried out on the combined data from the two studies. There were no significant differences in total, low-density-lipoprotein- or high-density-lipoprotein-cholesterol concentrations during fish-oil supplementation, although there was considerable individual variation in cholesterol responses to the supplement. Concentrations of Apo-B and Apo-A1 were unchanged during supplementation with fish oils. Fasting and early morning postprandial GIP concentrations were lower in subjects taking fish oils, possibly due to acute effects of fish-oil capsules taken on the evening before the studies. In both studies fasting insulin and glucose and postprandial insulin concentrations remained unchanged following fish-oil supplementation. The results do not support the view that triacylglycerol-lowering effects ofn-3 fatty acids are due to modulation of insulin secretion mediated via the enteroinsular axis. Further studies are required to determine the precise mechanism by which fish oils reduce both fasting and postprandial triacylglycerol concentrations.

Conference Article| October 01 1990 Fasting and postprandial triacylglycerol responses to a standard test meal in subjects taking dietary supplements of n − 3 fatty acids CHRISTINE M. WILLIAMS; CHRISTINE M. WILLIAMS 1Division of Nutrition and Food Science, Department of Biochemistry, University of Surrey, Guildford GU2 5XH, U.K. Search for other works by this author on: This Site PubMed Google Scholar FIONA MOORE; FIONA MOORE 1Division of Nutrition and Food Science, Department of Biochemistry, University of Surrey, Guildford GU2 5XH, U.K. Search for other works by this author on: This Site PubMed Google Scholar JOHN WRIGHT JOHN WRIGHT 1Division of Nutrition and Food Science, Department of Biochemistry, University of Surrey, Guildford GU2 5XH, U.K. Search for other works by this author on: This Site PubMed Google Scholar Biochem Soc Trans (1990) 18 (5): 909–910. https://doi.org/10.1042/bst0180909 Article history Received: March 07 1990 Views Icon Views Article contents Figures & tables Video Audio Supplementary Data Peer Review Share Icon Share Facebook Twitter LinkedIn MailTo Cite Icon Cite Get Permissions Citation CHRISTINE M. WILLIAMS, FIONA MOORE, JOHN WRIGHT; Fasting and postprandial triacylglycerol responses to a standard test meal in subjects taking dietary supplements of n − 3 fatty acids. Biochem Soc Trans 1 October 1990; 18 (5): 909–910. doi: https://doi.org/10.1042/bst0180909 Download citation file: Ris (Zotero) Reference Manager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search Search Dropdown Menu toolbar search search input Search input auto suggest filter your search All ContentAll JournalsBiochemical Society Transactions Search Advanced Search Keywords: VLDL, very-low-density lipoprotein, NIDDM, non-insulin-dependent diabetes mellitus, LDL, HDL, low-and high-density lipoprotein, respectively This content is only available as a PDF. © 1990 Biochemical Society1990 Article PDF first page preview Close Modal You do not currently have access to this content.

Conference Article| December 01 1989 Urinary carboxymethyl-lysine measurement as a potential indicator of diabetic complications BARRY J. GOULD; BARRY J. GOULD 1Department of Biochemistry, University of Surrey, Guildford, Surrey GU2 5XH, U.K. Search for other works by this author on: This Site PubMed Google Scholar DAVID P. WALSH; DAVID P. WALSH 1Department of Biochemistry, University of Surrey, Guildford, Surrey GU2 5XH, U.K. Search for other works by this author on: This Site PubMed Google Scholar ERIC AH-SING; ERIC AH-SING 1Department of Biochemistry, University of Surrey, Guildford, Surrey GU2 5XH, U.K. Search for other works by this author on: This Site PubMed Google Scholar JOHN WRIGHT; JOHN WRIGHT 1Department of Biochemistry, University of Surrey, Guildford, Surrey GU2 5XH, U.K. Search for other works by this author on: This Site PubMed Google Scholar BRIAN C. STACE BRIAN C. STACE 1Department of Biochemistry, University of Surrey, Guildford, Surrey GU2 5XH, U.K. Search for other works by this author on: This Site PubMed Google Scholar Biochem Soc Trans (1989) 17 (6): 1087–1088. https://doi.org/10.1042/bst0171087 Article history Received: June 14 1989 Views Icon Views Article contents Figures & tables Video Audio Supplementary Data Peer Review Share Icon Share Facebook Twitter LinkedIn MailTo Cite Icon Cite Get Permissions Citation BARRY J. GOULD, DAVID P. WALSH, ERIC AH-SING, JOHN WRIGHT, BRIAN C. STACE; Urinary carboxymethyl-lysine measurement as a potential indicator of diabetic complications. Biochem Soc Trans 1 December 1989; 17 (6): 1087–1088. doi: https://doi.org/10.1042/bst0171087 Download citation file: Ris (Zotero) Reference Manager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search Search Dropdown Menu toolbar search search input Search input auto suggest filter your search All ContentAll JournalsBiochemical Society Transactions Search Advanced Search Keywords: CML, carboxymethyl-lysine This content is only available as a PDF. © 1989 Biochemical Society1989 Article PDF first page preview Close Modal You do not currently have access to this content.

A peptide was extracted and purified from rat insulinoma tissue which, although similar, was not identical to normal rat C peptides. The purity of the peptide, called rat insulinoma peptide (RIP), was investigated using polyacrylamide gel electrophoresis, isoelectric focusing and high-performance liquid chromatography. It appears to contain two peptides similar to each other but differing in their isoelectric points. The peptides as assessed by fast atom bombardment mass spectrometry have molecular masses in the region of 1982 Da, given a chain length of approx. 22 amino-acid residues. Evidence obtained using an established rat C peptides radioimmunoassay suggests that RIP shares a common C-terminus with rat C peptides. The antiserum produced to RIP was used to develop a radioimmunoassay using a tracer prepared by iodinating purified tyrosylated RIP.

The blood glucose and plasma insulin responses to test milk samples were studied in eight insulin-dependent diabetics. After an overnight fast, the subjects (aged 20–45 years) were given a breakfast containing two Weetabix biscuits (20 g carbohydrate) with 500 ml of either regular (S) fat-free milk (25 g lactose) or 500 ml of a new low-lactose (D) fat-free milk (3.75 g lactose and 4.25 g fructose). The regular morning insulin dose was omitted. Mean basal plasma glucose level was slightly higher before S milk (11.4 vs. 10.1 mmol/l). The peak increment in plasma glucose was higher in S milk (9.4 vs. 6.6 mmol/l). The rise was 83% above basal (S) vs. 65% (D). Although the final mean plasma glucose concentration was not significantly higher 3 h after S milk compared with D milk (17.9 vs. 14.3 mmol/l) the incremental area under the plasma glucose curve was much greater (p<0.001) with S milk than with D milk (1266±295 units vs. 909±242 units). No galactose was detectable in any sample and there was no difference in plasma Β-hydroxybutyrate levels. The results suggest that the low-lactose fat-free milk (D) may be suitable for diabetic diets and weight reducing diets due to the lower contribution of energy. The results suggest that fat-free milk does not exert a fast action on blood glucose concentration and therefore fat-free milk and especially low-lactose fat-free milk may also prove to be suitable for diabetic diets.

SUMMARY At two different times of year (spring and autumn) an oral preparation of the pineal neurohormone melatonin, or placebo, was administered to 12 healthy volunteers (10 men and two women in spring: the same group minus one man in autumn) daily at 1700 h for 1 month (spring), or 3 weeks (autumn) using a double‐blind cross‐over protocol. The daily dose was 2 mg melatonin in 5 ml corn‐oil, and placebo consisted of the vehicle only. In spring the anterior pituitary hormones LH, PRL, GH together with T4, cortisol, testosterone and melatonin were measured at 1– to 6–h intervals for 24 h in plasma on the day following the last dose. In autumn PRL, cortisol and melatonin levels were measured on the last day of treatment. Subjective fatigue, mood and sleep records were kept throughout the studies. Melatonin increased early evening fatigue and actual sleep, but had no effect on mood: these results are reported in full elsewhere. Melatonin administration had no effect on the levels or 24‐h rhythm of LH, GH, T4, testosterone or cortisol. An earlier fall in the nocturnal PRL was observed on both occasions. Overall PRL levels were higher in spring than in autumn. In five of the subjects, the secretion of endogenous melatonin was advanced by 1–3 h in the presence of exogenous melatonin. These observations suggest that the potential therapeutic use of melatonin as a hypnotic or in the treatment of jet lag is unlikely to be complicated by undesirable endocrine effects.

An assessment of the rhythmic characteristics of melatonin secretion in man and other species requires the determination of 24-h secretion profiles. Measurement of a major excreted metabolite would allow noninvasive study of pineal function, applicable in particular to pediatric and long term circadian rhythm studies. This report describes a simple and rapid RIA for 6-hydroxymelatonin sulfate in human plasma and urine. Physiological studies revealed that both plasma and urinary levels of 6-hydroxymelatonin sulfate were closely related to plasma melatonin, and that the urinary 24-h rhythm was abolished by the beta 1-adrenergic anagonist atenolol.

Conference Abstract| December 01 1984 A Clinically Useful Assay for Melatonin Metabolites J. Arendt; J. Arendt 1Department of Biochemistry, University of Surrey, Guildford, Surrey, U.K. Search for other works by this author on: This Site PubMed Google Scholar C. Bojkowski; C. Bojkowski 1Department of Biochemistry, University of Surrey, Guildford, Surrey, U.K. Search for other works by this author on: This Site PubMed Google Scholar C. Franey; C. Franey 1Department of Biochemistry, University of Surrey, Guildford, Surrey, U.K. Search for other works by this author on: This Site PubMed Google Scholar J. Wright; J. Wright 1Department of Biochemistry, University of Surrey, Guildford, Surrey, U.K. Search for other works by this author on: This Site PubMed Google Scholar V. Marks V. Marks 1Department of Biochemistry, University of Surrey, Guildford, Surrey, U.K. Search for other works by this author on: This Site PubMed Google Scholar Author and article information Publisher: Portland Press Ltd Online ISSN: 1470-8736 Print ISSN: 0143-5221 © 1984 The Biochemical Society and the Medical Research Society1984 Clin Sci (Lond) (1984) 67 (s9): 68P–69P. https://doi.org/10.1042/cs067068Pb Views Icon Views Article contents Figures & tables Video Audio Supplementary Data Peer Review Share Icon Share Facebook Twitter LinkedIn Email Cite Icon Cite Get Permissions Citation J. Arendt, C. Bojkowski, C. Franey, J. Wright, V. Marks; A Clinically Useful Assay for Melatonin Metabolites. Clin Sci (Lond) 1 December 1984; 67 (s9): 68P–69P. doi: https://doi.org/10.1042/cs067068Pb Download citation file: Ris (Zotero) Reference Manager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search Search Dropdown Menu toolbar search search input Search input auto suggest filter your search All ContentAll JournalsClinical Science Search Advanced Search This content is only available as a PDF. © 1984 The Biochemical Society and the Medical Research Society1984 Article PDF first page preview Close Modal You do not currently have access to this content.