Circadian and ultradian variation in pancreatic secretion of meal-fed pigs after weaning

We studied the time structure of pancreatic secretion in two experiments involving seven 6- to 7-wk-old intact male pigs, surgically fitted with a jugular vein catheter for blood sampling, pancreatic catheter, and a duodenal T-cannula for chronic pancreatic juice sampling for 72 h at 30- to 60-min intervals. Pigs were kept in metabolic cages in a regimen of 12 h of light alternating with 12 h of darkness and were fed at 0800, 1500, and 2200 daily a standard diet based on barley, soybean meal, and fish meal. Beginning 4 d after surgical recovery, three 24-h collections of pancreatic juice and blood sampling were begun either at 0700 or 0800 every 2nd d for 5 d. Pancreatic secretion exhibited a pattern characterized by distinct meal-related secretions of the first phase (postprandial), containing large amounts of protein and enzymes (trypsin and chymotrypsin), and by non-food-stimulated secretions of the second phase with less protein and enzymes. During the dark span, the first phase was practically absent; the response of the pancreatic secretion to the 2200 meal was not very pronounced. Apart from the anticipated circadian rhythm demonstrable by single cosinor analysis on a group basis, a prominent 8-h component was almost invariably statistically significant. Moreover, an approximately 3.43-h component was also prominent. These data indicate that pancreatic secretions are circadian periodic and that their response to a standard meal is also circadian-stage dependent. The circadian components may have been free-running because the pigs were adjusting themselves to the changing phase and that resulted in the period being different from exactly 24 h.

Prevalence of winter depression in Denmark

An unselected cohort of 3556 subjects in Copenhagen was asked to complete the Seasonal Pattern Assessment Questionnaire (SPAQ) for estimating the presence of seasonal affective disorders (SAD or winter depression). Completed questionnaires were received from 1794 subjects in total. About 12% of the respondents had a Global Seasonality Score (GSS) high enough to indicate the presence of SAD. Among those respondents without SAD, women and younger people were found to be much more sensitive to seasonal and weather changes than men and older people, respectively.

Molecular phylogeny and evolution of Monilinia (Sclerotiniaceae) based on coding and noncoding rDNA sequences

The nuclear internal transcribed spacers, the 5.8S subunit, ~560 bp of the small subunit, and ~320 bp of the large subunit of the nuclear ribosomal DNA repeat from 17 species of Monilinia and eight species of closely related genera were sequenced. Phylogenies were constructed using maximum parsimony. The results support the hypothesis that Monilinia is not monophyletic. A fundamental distinction was found between the section Junctoriae and the section Disjunctoriae. Four evolutionary lineages were identified within the Disjunctoriae: one species on Crataegus, one group of species on dry stone fruits of rosaceous hosts, one group of species on capsular fruits of ericaceous hosts, and one group of species on sweet berry fruits of ericaceous hosts. Comparisons between branching topologies of hosts and Monilinia species suggest that although cospeciation among hosts and parasites has been the rule, several host jumps have taken place. Sclerotinia pirolae was determined to be a true member of the Disjunctoriae. The closest taxon groups to the Junctoriae were found to be Botrytis and Sclerotinia, with Ciborinia being the closest taxon group to the Disjunctoriae. There is evidence of an increased rate of ssrRNA evolution in the lineage of species that attack ericaceous berries.

Development of digestive enzymes in pigs with emphasis on lipolytic activity in the stomach and pancreas

The effect of age and weaning on the activities of digestive enzymes with emphasis on the lipolytic enzymes before and after weaning was investigated. The activities of amylase, chymotrypsin, trypsin, carboxyl ester hydrolase, pancreatic lipase, and colipase in pancreatic tissue and the activity of gastric lipase in the cardiac mucosa of the stomach in 45 pigs were response variables. The activity of trypsin was not affected by weaning and the rate of increase was similar during the whole experiment. The activities of chymotrypsin and amylase decreased at weaning (P < .05). After weaning the activity of chymotrypsin increased more slowly than before weaning (P < .001), whereas the rate of increase of amylase activity remained unchanged. Lipase, colipase, and carboxyl ester hydrolase activities decreased at weaning (P < .001), whereas gastric lipase activity increased at weaning (P < .01). The development of lipase, colipase, and carboxyl ester hydrolase activity decreased postweaning (P < .01), whereas gastric lipase activity increased before weaning and remained constant after weaning. Pancreatic lipase had a considerably higher capacity for hydrolyzing tributyrin, and the total activity of pancreatic lipase was up to 600 times higher than that of gastric lipase. The lipolytic enzymes displayed a non-parallel pattern of development, and we suggest that this reflects the importance of these enzymes during the suckling and postweaning phases, respectively. However, the significance of gastric lipase for the digestion of fat in pigs remains to be elucidated.

Inclusion of oxidized vegetable oil in broiler diets. Its influence on nutrient balance and on the antioxidative status of broilers

Over a period of 4 wk, 24 10-d-old broiler hens were fed diets containing 11% vegetable oil (9% rapeseed oil, 2% soybean oil), which was added either fresh (1 meq O2/kg oil) or oxidized (156 meq O2/kg oil). The effects of the dietary treatments on nutrient digestibility were examined in a balance experiment. The antioxidative status of the animals was evaluated using plasma concentrations of thiobarbituric acid-reactive substances (TBARS), erythrocyte hemolysis in vitro, selenium-dependent and selenium-independent activity of glutathione peroxidase in liver cell cytosolic fractions, and concentrations of tocopherols and other fat-soluble compounds with antioxidative properties (lutein, beta-carotene, and retinol) in plasma and various tissues (skeletal muscle, cardiac muscle, liver, and abdominal fat). Compared to the fresh oil, the concentrations of linoleic and linolenic acid were slightly lower in oxidized oil. The concentration of alpha-tocopherol in the diet with fresh oil was an average of 80.8 mg/kg diet, whereas the diet with oxidized oil only provided 44 mg/kg. The dietary selenium content averaged 0.48 mg/kg in both diets. During the experiment, none of the animals showed symptoms of diarrhea or vitamin E deficiency. The intake of oxidized oil caused a growth depression after 2 wk. The retention of fat (P = 0.07), energy (P = 0.09), and alpha-tocopherol (P < 0.01) was lower in the group fed oxidized fat. Furthermore, these animals showed significantly higher plasma concentrations of TBARS (P < 0.01), and lower concentrations of tocopherols, lutein, beta-carotene, and retinol in plasma and tissues.

The pattern of protein retention in pigs from 2 to 120 kg live weight

1. Data from experiments with growing pigs of Danish Landrace (n = 782) including measurements of nitrogen and energy balances were scrutinized in order to select observations in which maximum protein retention (RP) were expected. 2. The criterions for selection were based on intake of metabolizable energy and oxidation of nutrients and a total of 152 measurements in the live weight (LW) range from 2 to 120 kg complied with the criterions. 3. The selected material were used in a quadratic function of RP on metabolic weight (kg0.75) to describe the curve for maximum RP. 4. The function obtained was: RP, g/d = 11.55 x kg0.75 - 0.185 x kg1.50 with a maximum of 180 g/d at 98 kg LW. 5. The RP-values were compared with data from the literature with other races and the function seems well established to describe maximum protein retention in non-hormone treated or specific selected pigs.

Supplementation of broiler diets with all-rac-alpha- or a mixture of natural source RRR-alpha-,gamma-,delta-tocopheryl acetate. 2. Effect on the oxidative stability of raw and precooked broiler meat products

Oxidative stability of muscle from broilers fed 1) basal feed; 2) basal feed supplemented with 100 mg of a mixture of natural source RRR-alpha-,gamma-,delta-tocopheryl acetate/kg feed; 3) basal feed supplemented with 100 mg of synthetic all-rac-alpha-tocopheryl acetate/kg feed; 4) basal feed supplemented with 500 mg of a mixture of natural source RRR-alpha-,gamma-,delta-tocopheryl acetate/kg feed; or 5) basal feed supplemented with 500 mg of synthetic all-rac-alpha-tocopheryl acetate/kg feed, was evaluated during chill and freezer storage by determination of thiobarbituric acid reactive substances (TBARS). The oxidative stability of precooked muscle was investigated in a chill storage experiment and in a model system with accelerated oxidation. The basal feed contained a standard added amount of 46 mg all-rac-alpha-tocopheryl acetate/kg feed. Furthermore, the basal feed had a high natural content of vitamin E, resulting in a dietary vitamin E level in the control feed of 72 mg alpha-tocopherol and 69 mg gamma-tocopherol, a level that provided a reasonable oxidative stability for the meat. In spite of this, raising the dietary vitamin E level resulted in improved oxidative stability of broiler muscle during storage. Supplementation of broiler feed with 100 mg all-rac-alpha-tocopheryl acetate/kg, resulting in a total alpha-tocopherol content of 198 mg/kg feed, was found to be sufficient to improve stability of precooked broiler breast and precooked thigh muscles during chill storage, and further to ensure stability of raw meat during chill and freezer storage. The mixture of natural source RRR-alpha-,gamma-,delta-tocopherol was less effective in protecting broiler muscles than the synthetic all-rac-alpha-tocopherol, when compared on a weight basis.

Supplementation of broiler diets with all-rac-alpha- or a mixture of natural source RRR-alpha-,gamma-,delta-tocopheryl acetate. 1. effect on vitamin E status of broilers in vivo and at slaughter

A total of 300 female broiler chickens were reared from day-old to 10 d of age on the same starter diet. Then they were divided into five groups, receiving a control diet (Group 1) relatively rich in fat (14.3%) and unsaturated fatty acids (87.6%) and standardized with respect to vitamins and minerals, supplemented with 100 mg (Group 2) and 500 mg (Group 4) of RRR-alpha-,gamma-,delta-tocopheryl acetate/kg feed (40.6% alpha-, 41.1% gamma-, 18.3% delta-) or 100 mg (Group 3) and 500 mg (Group 5) all-rac-alpha-tocopheryl acetate/kg feed until slaughter at 6 wk of age. No differences between the supplemented groups were observed with respect to weight gain, feed consumption, packed cell volume (PCV), plasma enzyme activities of creatine kinase (CK) and glutathione peroxidase (GSH-Px), fatty acid composition, and enzyme activities of citrate synthase (CS), and total lactate dehydrogenase (LDH), and 3-OH-acyl-coenzyme A-dehydrogenase (HAD) of breast (Pectoralis major) and thigh (Gastrocnemius interna) muscle. Increasing levels of alpha-, gamma-, and delta-tocopherol were found in blood plasma with increasing dietary levels of these tocopherols. Only alpha-tocopherol was detectable in skeletal muscle and in higher concentrations in thigh than in breast muscle. Hemolysis in vitro and plasma activity of aspartate aminotransferase (ASAT) were lower (P < .01) in Groups 2 and 4 than in Groups 3 and 5. Interactions were observed between dietary type and concentration of tocopherols for plasma CK, GSH-Px, Na+, and K+. No measurable excretion of ethane and pentane was observed in any of the groups. The findings indicate that the oxidative stress in the live animals was minimal. The mixture of natural source RRR-alpha-,gamma-,delta-tocopherols was as efficient in protecting the live chickens as the all-rac-alpha-tocopheryl acetate, when provided on a weight basis as judged from the chosen in vivo parameters of vitamin E status.

The pattern of the circadian rhythm of pancreatic secretion in fed pigs

The pattern of the circadian rhythm of pancreatic secretion was studied in four 6- to 7-wk-old intact male pigs that were kept in metabolic cages under 12 h light:12 h dark cycles and fed three times a day at 0800, 1500, and 2200. Three 24-h collections of pancreatic juice and blood were begun at 0800 every 2nd day during 5 d. A biphasic pattern of the exocrine pancreas was detected. Secretions during the first phase (postprandial peak) contained large amounts of protein and enzymes, and secretions appeared immediately after feed ingestion. Secretions during the second phase (between meals) had lesser amounts (P < .001) of protein and enzymes, but were of longer duration (P < .001). The output of protein and trypsin activity were generally correlated (P < .001) with each other, but the correlation of either with the volume outflow were small. However, these variables were correlated (P < .01) with the volume outflow at night during the second phase. Plasma concentrations of insulin and glucose increased after each meal, but the increase was significant (P < .05) only for insulin. Insulin and glucose concentrations were correlated (P < .01) with each other after the meals at 0800 and 1500. The results indicated a biphasic pattern of the exocrine pancreas and a monophasic pattern of the endocrine pancreas in pigs. The regulation of these patterns seems to vary during the 24-h period. Furthermore, feed enhanced secretion, but it did not seem to be the only factor controlling the circadian pattern.

Labeling of surface proteins of herpes simplex virus type 1 using a modified biotin-streptavidin system

Methods of labeling surface proteins on herpes simplex virus (HSV) which have minimal effect on the biological activity of the virus are useful for the study of both the localization and function(s) of surface proteins. The present work describes a procedure using a water-soluble biotin compound, sulfo-NHS-biotin, which is unable to penetrate biological membranes and reacts with primary amines in proteins. Labeled proteins were detected by binding of [125I]streptavidin. Specific reaction with surface proteins was shown in Western blots using antibodies against selected proteins in the envelope or in the tegument. Proteins susceptible to iodination were also biotinylated, but the efficiency of labeling varied from one protein to another. As a result of freezing and thawing of the virus, as well as the manipulations involved in Ficoll gradient purification, internal proteins were labeled. The infectivity of the virus was reduced by approximately 40% after biotinylation. Labeled viruses were visualized by fluorescein isothiocyanate-conjugated streptavidin, and seen as distinct spots on the surface of the cells.

The local differential effect of prostacyclin, prostaglandin E2 and prostaglandin F2 alpha on mammary blood flow of lactating goats

Mammary blood flow (MBF) and milk yield are closely related in dairy ruminants, but little is known about the regulation of MBF in vivo. The local effects on MBF of injections or continuous infusions into the mammary artery of prostaglandins (PG) or indomethacin (an inhibitor of prostaglandins) respectively, were investigated in surgically prepared conscious goats. Prostacyclin (PGI2) was found to be a potent stimulator of MBF which increased linearly over the dose range 50-1000 ng. PGE2 was almost as potent as PGI2 at low doses, but tachyphylaxis occurred at doses at and above 100 ng. The response to repeated injections of PGE2 quickly declined depending on the dose. PGF2 alpha had no effect on MBF. During infusion of indomethacin into the mammary artery MBF was reduced markedly, showing that endogenous mammary prostaglandins are involved in the regulation of vasodilatation. The results indicate that PGI2 (and to a lesser extent PGE2) has an important role in the local regulation of vascular tone in the mammary gland.

The influence of dietary ethoxyquin on the vitamin E status in broilers

In a feeding experiment with 48 male broiler chickens was the effect of dietary ethoxyquin and dl-alpha-tocopherol acetate on vitamin E status of chickens investigated. The experimental diets were offered the chickens from the first day of age until the end of the experiment at 42 days. Chickens were fed on diets containing 0, 75, or 150 mg ethoxyquin/kg feed, with (30 mg/kg feed) or without added dl-alpha-tocopherol acetate. The concentration of alpha-tocopherol in plasma of chickens on dl-alpha-tocopherol acetate supplemented diets were significantly higher than those of chickens fed on the nonsupplemented diets. Supplementation with alpha-tocopherol acetate reduced the haemolysis in vitro. Ethoxyquin seemed to have an increasing effect on the concentration of alpha-tocopherol in plasma, but not in the liver. Addition of ethoxyquin to diets without dl-tocopherol acetate reduced the concentration of gamma-tocopherol in plasma. Significant interactions between the addition of ethoxyquin and the addition of dl-alpha-tocopherol acetate to the feed were observed on the haemolysis in vitro and the activity of glutathione peroxidase in plasma. The results indicate that incorporation of ethoxyquin in the diets of chickens exert an improving effect on the vitamin E status of the organism.

Changes in mammary uptake of free fatty acids, triglyceride, cholesterol and phospholipid in relation to milk synthesis during lactation in goats

Uptake of free fatty acids (FFA), triglycerides (TG), cholesterol (CHOL) and phospholipids (PL) was measured in both mammary glands of dairy goats during lactation. Arterial concentrations of TG, CHOL and PL as well as arterio-venous difference (AV) and extraction rate (E) for TG were highest in goats with the highest dietary feed intake. AV were linearly related to arterial concentrations for the four lipid classes, and arterial concentrations of CHOL were linearly related to output of lactose, protein and fat in milk. Arterial supply, and not mammary synthetic activity, is the main determinant of mammary FFA, TG and CHOL uptake.

Studies on responses to potassium, noradrenaline, serotonin, histamine and prostaglandin F2 alpha, of isolated pudendal arteries from non-lactating goats

The effects of potassium (K+), noradrenaline (NA), serotonin (5-HR), histamine (Hi) and prostaglandin F2 alpha (PGF2 alpha) were studied on isolated pudendal arteries from non-lactating goats. K+, NA, 5-HT, Hi and PGF2 alpha had concentration-dependent contractile effects on the arteries. The developed tensions were, in order of potencies, 5-HT > NA > PGF2 alpha > Hi > K+. NA induced a significantly higher maximal contractile force than K+, 5-HT, PGF2 alpha and Hi. Pretreatment with cocaine was without significant effect on the contractile response to NA. The contractile response to Hi was totally eliminated by mepyramine. Ca2+ had a concentration-dependent contractile effect on arteries depolarized by 125 mM K+. The results indicate that NA, 5-HT and PGF2 alpha may play essential roles in the regulation of goat mammary blood flow. The response to K+ is highly dependent on extracellular Ca2+. The contractile response to histamine may be mediated via H1-receptors. The in vitro method used is well suited to study the vascular reactivity in different regions of the mammary vascular bed.

Heat production and quantitative oxidation of nutrients by physical activity in humans

The effect of physical activity on heat production and oxidation of nutrients was measured by means of indirect calorimetry. The experiment included 6 male and 4 female healthy subjects who, during a 24-hour stay in the respiration chambers, performed, in the morning and afternoon, 15 min cycling with the total work of 6,750 kg m. Experiments were repeated twice (3- to 4-week interval) showing no differences between the gas exchange in the morning and afternoon and between first and second experiment. The gas exchange during cycling was about 4 times higher than during basal periods. The identical work of 66.2 kJ by cycling caused on average a heat increment of 309 kJ, yielding the mean energetic efficiency for the performed work of 0.22. The activity caused an increment of 11.5 g oxidized carbohydrate and 2.6 g oxidized fat.

Heat production and quantitative oxidation of nutrients by physical activity in pigs

Two groups of pigs weighing 90 (Expt A) or 80 (Expt B) kg walked on a horizontal moving rubber belt for a distance of 315 m at a speed of 25.6 +/- 0.38 and 28.8 +/- 0.35 m/min respectively for 10 min in an open-air-circuit respiration unit. From measurements of VO2 and VCO2, heat production and oxidation of carbohydrate and fat were calculated 30 min before (I), 10 min during walking (II) and in intervals of 10 min (III, IV) and 30 min (V) after walking. Heat production increased 2-3 times in section II in relation to section I, remained high for 20 min in section III and IV, but reached the basal line in section V. Oxidation of carbohydrate was the main source for heat production.

Changes in mammary glucose and protein uptake in relation to milk synthesis during lactation in high- and low-yielding goats

1. Glucose and protein uptake were measured in both mammary glands of two low- and two high-yielding dairy goats during lactation. 2. Low-yielding goats tended to have higher arterial glucose concentrations, but approximately 40% lower arterio-venous differences (AV) and extraction rates (E) for glucose than high-yielding goats. 3. AV and E for glucose (but not protein) were linearly related to yields of both lactose, milk protein and fat. 4. Mammary uptake of glucose is determined primarily by mammary glucose metabolism, not glucose supply; lower intracellular glucose concentration in mammary cells of genetically superior animals thus explains the more efficient mammary uptake.

Distribution of hydroxylated vitamin D metabolites [25OHD3 and 1,25(OH)2D3] in domestic pigs: evidence that 1,25(OH)2D3 is stored outside the blood circulation?

1. The distribution of 25-hydroxycholecalciferol (25OHD3) and 1,25-dihydroxycholecalciferol [1,25(OH)2D3] in various organs from domestic pigs was examined by HPLC. 2. Plasma levels of both metabolites corresponded to those found in healthy human subjects. 3. Tissue concentrations of 25OHD3 in fat, kidney, liver, and intestinal mucosa were low (< 1/3 of plasma levels), whereas tissue concentrations of 1,25(OH)2D3 exceeded plasma levels by factors 3-7, adipose tissue concentrations being the highest. 4. Substantial amounts of activated vitamin D are stored outside the blood-streams and may actively participate in vitamin D and calcium homeostasis.

The respiratory quotient in relation to fat deposition in fattening-growing pigs

The relationship between non-protein respiratory quotient (RQnp) and total fat retention (RFAT) or fat retained from synthesized carbohydrates (RFAT(CHO)) was evaluated from experiments with fattening--growing pigs in the live weight (LW) range from 45 to 120 kg. A commercial feed compound (31 g fat/kg) was fed at low (LI) or high (HI) feed intake in Expt 1, while a semi-purified diet (9.5 g fat/kg) was given without (LO) or with (HO) supplement of 90 g soya-bean oil/kg in Expt 2. RQnp was calculated from 24 h measurements of the gas exchange, RFAT from 7 d N and C balances and RFAT(CHO) from differences between RFAT and digested fat. The measurements showed that about 85% of the total gas exchange was caused by oxidation of non-protein nutrients and the RQnp varied from 1.00 to 1.34. In Expt 1 RFAT increased with LW from 46 to 141 and from 199 to 335 g/d on LI and HI respectively, whilst in Expt 2 RFAT increased from 191 to 377 and from 267 to 511 g/d on LO and HO respectively. A pronounced linearity was found between RQnp and RFAT for all diets, but the curve for Expt 2 on HO had a lower position than the common curve for the other diets. By relating RQnp to RFAT(CHO) a common linear curve and regression equation could be established in spite of the great variation in dietary composition, intake of fat and fat deposition.