Comparison of insulins detemir and glargine: effects on glucose disposal, hepatic glucose release and the central nervous system.

AIMS: The effects of insulins detemir (Det) and glargine (Glar) on endogenous glucose production (EGP) and net hepatic glucose output (NHGO) were compared. METHODS: Arteriovenous difference and tracer ([3-(3) H]glucose) techniques were employed during a two-step hyperinsulinemic euglycaemic clamp in conscious dogs (6 groups, n = 5-6/group). After equilibration and basal sampling (0-120 min), somatostatin was infused and basal glucagon was replaced intraportally. Det or Glar was infused via portal vein (Po), peripheral vein (IV), or bilateral carotid and vertebral arteries (H) at 0.1 and 0.3 mU/kg/min (low Insulin; Glar vs. Det, respectively, 120-420 min) and 4× the low insulin rate (high insulin; 420-540 min). RESULTS: NHGO and EGP were suppressed and glucose R(d) and infusion rate were stimulated similarly by Det and Glar at both Low and high insulin with each infusion route. Non-esterified fatty acid (NEFA) concentrations during low insulin were 202 ± 37 versus 323 ± 75 µM in DetPo and GlarPo (p < 0.05) and 125 ± 39 versus 263 ± 48 µM in DetIV and GlarIV, respectively (p < 0.05). In DetH versus GlarH, pAkt/Akt (1.7 ± 0.2 vs. 1.0 ± 0.2) and pSTAT3/STAT3 (1.4 ± 0.2 vs. 1.0 ± 0.1) were significantly increased in the liver but not in the hypothalamus. CONCLUSIONS: Det and Glar have similar net effects on acute regulation of hepatic glucose metabolism in vivo regardless of delivery route. Portal and IV detemir delivery reduces circulating NEFA to a greater extent than glargine, and head detemir infusion enhances molecular signalling in the liver. These findings indicate a need for further examination of Det's central and hepatic effects.

Gastrointestinal stromal tumour presenting acutely as gastroduodenal intussusception.

INTRODUCTION: Gastrointestinal stromal tumours (GISTs) are uncommon tumours of the gastrointestinal (GI) tract. We report a case of a gastric GIST that presented acutely as a gastroduodenal intussusception. CASE PRESENTATION: A 59-year-old woman presented with a week's history of vomiting anything she swallowed. Physical examination revealed a mildly tender abdomen without guarding or rebound tenderness. An epigastric mass was, however, palpated. Abdominal ultrasonography suggested an intussusception. At laparotomy, a tumour on the anterior wall of the stomach causing intussusception of the stomach into the duodenum was found. After reducing the intussusception, a wedge resection of the tumour was performed, which proved to be a GIST. DISCUSSION: GISTs represent a rare group of neoplasms of the GI tract. Gastric intussusception is a rarely documented condition. Symptoms range from intermittent epigastric pain to sudden onsets of severe pain with vomiting and shock. Pre-operative diagnosis can be difficult and diagnosis cannot be confirmed until surgery. The treatment of choice for localised gastric GIST is surgical resection. CONCLUSION: Although gastroduodenal intussusception, particularly secondary to a GIST, is uncommon, clinicians need to have a high index of suspicion in acutely vomiting patients, especially if they have experienced similar symptoms intermittently in the immediate past.

Clinical immunology review series: an approach to the patient with anaphylaxis.

Anaphylaxis is a severe, life-threatening, generalized or systemic hypersensitivity reaction. While there is agreement as to this definition of anaphylaxis, the clinical presentation is often variable and it is not uncommon for there to be debate after the event as to whether anaphylaxis had actually occurred. The management of anaphylaxis falls into two distinct phases: (1) emergency treatment and resuscitation of a patient with acute anaphylaxis and (2) the search for a cause for the event and the formulation of a plan to prevent and treat possible further episodes of anaphylaxis. Both aspects are important in preventing death from anaphylaxis and are covered in this review.

Leupeptin inhibits adrenocorticotropic hormone-induced protein breakdown in the conscious dog.

To elucidate the role of proteinase inhibitors in the regulation of protein breakdown in vivo, we measured the effect of leupeptin on the rate of appearance of leucine in the plasma compartment in overnight-fasted conscious dogs. Two groups of dogs were studied. The control group (I) received saline infusion, and the experimental group (II) was rendered hypercatabolic with daily administration of adrenocorticotropic hormone (ACTH) (500 U/d) for 4 d.ACTH treatment increased plasma cortisol from 2+/-0.4 to 17+/-2 mug/dl (P < 0.005). It raised plasma leucine levels (mumol/liter) from 123+/-6 in I to 206+/-5 in II (P < 0.01) and its rate of appearance into the plasma compartment (micromoles per kilogram per minute) from 3.1+/-0.1 in I to 4.6+/-0.3 in II (P < 0.01). Whole blood alanine concentration (micromoles per liter) increased by 50% (from 387+/-31 to 577+/-53, P < 0.01) and whole blood glutamine concentration (micromoles per liter) increased from 653+/-51 to 917+/-93 (P < 0.01). Leupeptin infusion in the ACTH-treated group significantly decreased both the concentration of plasma leucine and its rate of appearance. Blood glutamine declined by 30% (P < 0.05) after leupeptin, but no effect on blood alanine was observed. Leupeptin had no effect on the saline control group. These data indicate that leupeptin decreases the accelerated rate of protein breakdown induced by cortisol excess. The fact that it did not affect protein degradation in controls may indicate that control of protein breakdown in the postabsorptive state may differ from that during accelerated turnover. Thus, the antibiotic proteinase enzyme inhibitors may be potentially useful in treating conditions of inappropriate protein breakdown.

Role of insulin in the regulation of leucine kinetics in the conscious dog.

To study the effect of insulin on leucine kinetics, three groups of conscious dogs were studied after an overnight fast (16-18 h). One, saline-infused group (n = 5), served as control. The other two groups were infused with somatostatin and constant replacement amount of glucagon; one group (n = 6) received no insulin replacement, to produce acute insulin deficiency, and the other (n = 6) was constantly replaced with 600 muU/kg per min insulin, to produce twice basal hyperinsulinemia. Hepatic and extrahepatic splanchnic (gut) balance of leucine and alpha-ketoisocaproate (KIC) were calculated using the arteriovenous difference technique. l,4,5,[(3)H]Leucine was used to measure the rates (micromoles per kilogram per minute) of appearance (Ra) and disappearance (Rd), and clearance (Cl) of plasma leucine (milliliters per kilogram per minute). Saline infusion for 7 h resulted in isotopic steady state, where Ra and Rd were equal (3.2+/-0.2 mumol/kg per min). Acute insulin withdrawal of 4-h duration caused the plasma leucine to increase by 40% (P < 0.005). This change was caused by a decrease in the outflow of leucine (Cl) from the plasma, since Ra did not change. The net hepatic release of the amino acid (0.24+/-0.03 mumol/kg per min) did not change significantly; the arterio-deep femoral venous differences of leucine (-10+/-1 mumol/liter) and KIC (-12+/-2 mumol/liter) did not change significantly indicating net release of the amino and ketoacids across the hindlimb. Selective twice basal hyperinsulinemia resulted in a 36% drop in plasma leucine (from control levels of 128+/-8 to 82+/-7 mumol/liter, P < 0.005) within 4 h. This was accompanied by a 15% reduction in Ra and a 56% rise in clearance (P < 0.001, both). Net hepatic leucine production and net release of leucine and KIC across the hindlimb fell markedly. These studies indicate that physiologic changes in circulating insulin levels result in a differential dose-dependent effect on total body leucine metabolism in the intact animal. Acute insulin withdrawal exerts no effect on leucine rate of appearance, while at twice basal levels, insulin inhibited leucine rate of appearance and stimulated its rate of disappearance.

Importance of the route of intravenous glucose delivery to hepatic glucose balance in the conscious dog.

To assess the importance of the route of glucose delivery in determining net hepatic glucose balance (NHGB) eight conscious overnight-fasted dogs were given glucose via the portal or a peripheral vein. NHGB was measured using the arteriovenous difference technique during a control and two 90-min glucose infusion periods. The sequence of infusions was randomized. Insulin and glucagon were held at constant basal levels using somatostatin and intraportal insulin and glucagon infusions during the control, portal, and peripheral glucose infusion periods (7 +/- 1, 7 +/- 1, 7 +/- 1 microU/ml; 100 +/- 3, 101 +/- 6, 101 +/- 3 pg/ml, respectively). In the three periods the hepatic blood flow, glucose infusion rate, arterial glucose level, hepatic glucose load, arterial-portal glucose difference and NHGB were 37 +/- 1, 34 +/- 1, 32 +/- 3 ml/kg per min; 0 +/- 0, 4.51 +/- 0.57, 4.23 +/- 0.34 mg/kg per min; 101 +/- 5, 200 +/- 15, 217 +/- 13 mg/dl; 28.5 +/- 3.5, 57.2 +/- 6.7, 54.0 +/- 6.4 mg/kg per min; +2 +/- 1, -22 +/- 3, +4 +/- 1 mg/dl; and 2.22 +/- 0.28, -1.41 +/- 0.31, and 0.08 +/- 0.23 mg/kg per min, respectively. Thus when glucose was delivered via a peripheral vein the liver did not take up glucose but when a similar glucose load was delivered intraportally the liver took up 32% (P less than 0.01) of it. In conclusion portal glucose delivery provides a signal important for the normal hepatic-peripheral distribution of a glucose load.

Beta-endorphin inhibits glucose production in the conscious dog.

The effect of human beta-endorphin (h beta E) infusion (0.2 mg/h) on glucose homeostasis was studied in 10 conscious overnight fasted dogs in which endocrine pancreatic function was fixed at basal levels with somatostatin plus intraportal replacement of basal insulin and glucagon. h beta E caused a fall in plasma glucose from 107 +/- 5 to 76 +/- 6 mg/dl by 3 h (P less than 0.01). This was due to a 25% fall in tracer-determined glucose production (Ra; P less than 0.01). A significantly larger fall in Ra was observed in four dogs in which hypoglycemia was prevented by use of an exogenous glucose infusion (45 vs. 25%, P less than 0.05). These changes occurred in the absence of changes in circulating levels of insulin, glucagon, epinephrine, norepinephrine, and cortisol. We conclude that the naturally occurring opioid peptide, beta-endorphin, inhibits glucose production by the liver in vivo. This appears to be a direct effect of the opioid on the liver, since the inhibition took place in the absence of changes in the other hormones measured. These results suggest that endorphins act on glucose homeostasis in a complex way, both by affecting other glucoregulatory hormones as demonstrated elsewhere, and by directly modulating hepatic glucose production as shown here.

Effect of glucose, independent of changes in insulin and glucagon secretion, on alanine metabolism in the conscious dog.

To study the effects of hyperglycemia on the metabolism of alanine and lactate independent of changes in plasma insulin and glucagon, glucose was infused into five 36-h-fasted dogs along with somatostatin and constant replacement amounts of both insulin and glucagon. Hepatic uptakes of alanine and lactate were calculated using the arteriovenous difference technique. [14C]Alanine was infused to measure the conversion of alanine and lactate into glucose. Hyperglycemia (delta 115 mg/dl) of 2 h duration caused the plasma alanine level to increase by over 50%. This change was caused by an increase in the inflow of alanine into plasma since the net hepatic uptake of the amino acid did not change. Taken together, the above findings indicate that glucose per se can significantly impair the fractional extraction of alanine by the liver. Hepatic extraction of lactate was also affected by hyperglycemia and had fallen to zero within 90 min of starting the glucose infusion. This fall was associated with a doubling of arterial lactate level. Conversion of [14C]-alanine and [14C]lactate into [14C]glucose was suppressed by 60 +/- 11% after 2 h of hyperglycemia, and because this fall could not be entirely accounted for by decreased lactate extraction an inhibitory effect of glucose on gluconeogenesis within the liver is suggested. These studies indicate that the plasma glucose level per se can be an important determinant of the level of alanine and lactate in plasma as well as the rate at which they are converted to glucose.

Glucose disposal during insulinopenia in somatostatin-treated dogs. The roles of glucose and glucagon.

The first aim of this study was to determine whether the plasma glucose level can regulate hepatic glucose balance in vivo independent of its effects on insulin and glucagon secretion. To accomplish this, glucose was infused into conscious dogs whose basal insulin and glucagon secretion had been replaced by exogenous intraportal insulin and glucagon infusion after somatostatin inhibition of endogenous pancreatic hormone release. The acute induction of hyperglycemia (mean increment of 121 mg/dl) in the presence of basal levels of insulin (7+/-1 muU/ml) and glucagon (76+/-3 pg/ml) resulted in a 56% decrease in net hepatic glucose production but did not cause net hepatic glucose uptake. The second aim of the study was to determine whether a decrease in the plasma glucagon level would modify the effect of glucose on the liver. The above protocol was repeated with the exception that glucagon was withdrawn (83% decrease in plasma glucagon) coincident with the induction of hyperglycemia. Under this circumstance, with the insulin level basal (7+/-1 muU/ml) and the glucagon levels reduced (16+/-2 pg/ml), hyperglycemia (mean increment of 130 mg/dl) promoted marked net hepatic glucose uptake (1.5+/-0.2 mg/kg per min) and glycogen deposition. In conclusion, (a) physiological increments in the plasma glucose concentration, independent of their effects on insulin and glucagon secretion, can significantly reduce net hepatic glucose production in vivo but at levels as high as 230 mg/dl cannot induce net hepatic glucose storage and (b) in the presence of basal insulin the ability of hyperglycemia to stimulate net hepatic glucose storage is influenced by the plasma glucagon concentration.

Effects of morphine on glucose homeostasis in the conscious dog.

This study was designed to assess the effects of morphine sulfate on glucose kinetics and on glucoregulatory hormones in conscious overnight fasted dogs. One group of experiments established a dose-response range. We studied the mechanisms of morphine-induced hyperglycemia in a second group. We also examined the effect of low dose morphine on glucose kinetics independent of changes in the endocrine pancreas by the use of somatostatin plus intraportal replacement of basal insulin and glucagon. In the dose-response group, morphine at 2 mg/h did not change plasma glucose, while morphine at 8 and 16 mg/h caused a hyperglycemic response. In the second group of experiments, morphine (16 mg/h) caused an increase in plasma glucose from a basal 99 +/- 3 to 154 +/- 13 mg/dl (P less than 0.05). Glucose production peaked at 3.9 +/- 0.7 vs. 2.5 +/- 0.2 mg/kg per min basally, while glucose clearance declined to 1.7 +/- 0.2 from 2.5 +/- 0.1 ml/kg per min (both P less than 0.05). Morphine increased epinephrine (1400 +/- 300 vs. 62 +/- 8 pg/ml), norepinephrine (335 +/- 66 vs. 113 +/- 10 pg/ml), glucagon (242 +/- 53 vs. 74 +/- 14 pg/ml), insulin (30 +/- 9 vs. 10 +/- 2 microU/ml), cortisol (11.1 +/- 3.3 vs. 0.9 +/- 0.2 micrograms/dl), and plasma beta-endorphin (88 +/- 27 vs. 23 +/- 6 pg/ml); all values P less than 0.05 compared with basal. These results show that morphine-induced hyperglycemia results from both stimulation of glucose production as well as inhibition of glucose clearance. These changes can be explained by rises in epinephrine, glucagon, and cortisol. These in turn are part of a widespread catabolic response initiated by high dose morphine that involves activation of the sympathetic nervous system, the endocrine pancreas, and the pituitary-adrenal axis. Also, we report the effect of a 2 mg/h infusion of morphine on glucose kinetics when the endocrine pancreas is clamped at basal levels. Under these conditions, morphine exerts a hypoglycemic effect (25% fall in plasma glucose, P less than 0.05) that is due to inhibition of glucose production (by 25-43%, P less than 0.05). The hypoglycemia was independent of detectable changes in insulin, glucagon, epinephrine and cortisol, and was not reversed by concurrent infusion of a slight molar excess of naloxone. Therefore, we postulate that the hypoglycemic effect of morphine results from the interaction of the opiate with non-mu receptors either in the liver or the central nervous system.

The bio refinery; producing feed and fuel from grain.

It is both possible and practicable to produce feed and fuel from grain. Using the value of grain to produce renewable energy for transport, while using the remaining protein content of the grain as a valuable protein source for livestock and for fish, can be seen as a complimentary and optimal use of all the grain constituents. Consideration must be given to maximise the value of the yeast components, as substantial yeast is generated during the fermentation of the grain starch to produce ethanol. Yeast is a nutritionally rich feed ingredient, with potential for use both as feed protein and as a feed supplement with possible immunity and gut health enhancing properties. Bioprocessing, with the consequent economies of scale, is a process whereby the value of grain can be optimised in a way that is traditional, natural and sustainable for primarily producing protein and oil for feed with a co-product ethanol as a renewable fuel.

Epidemiological studies of burn patients in a burn center in Ghana: any clues for prevention?

BACKGROUND: Burn injuries are a serious problem worldwide, with most occurrences in low- and middle-income countries. Depending on the extent of injury, burn victims are faced with the challenges of fitting into society due to complications such as extensive scarring and contractures. The current study seeks to determine whether epidemiological studies of burn patients can provide guidelines to enhance burn prevention among the Ghanaian population. METHODS: Data from the Burns Registry of the Burns Intensive Care Unit (BICU) of Komfo Anokye Teaching Hospital (KATH) was obtained. Data on sex, age, aetiology, % total body surface area (TBSA), and admission outcomes from May 1, 2009, to April 30, 2013, were retrieved for a total of 487 patients during this period. RESULTS: Data on burn admissions comprising 263 (54.0 %) males and 224 (46.0 %) females were obtained from the Burns Registry. Children 0-10 years were the most affected age group. The yearly mean % TBSA ranged from 24.74 % to 35.07 %. The majority of burns was caused by scalding. Mortality rates ranged from 8.4 % to 32.0 % during the period under review. CONCLUSIONS: The study shows that children of 10 years old and below are the most affected group; this may be due to inattention to these children by parents/caretakers. Safety and safe working environments should be provided at home and workplaces, and promotion of education on burn prevention should be intensified.

Altered ability of the liver to produce glucose following a period of glucagon deficiency.

It is known that the effectiveness of a physiologic increment in glucagon to stimulate glucose production wanes with time even when counterregulatory insulin secretion is prevented. The aim of the present study was to establish whether the converse is true: does glucagon become a more effective stimulus of glucose production following a period of acute hypoglucagonemia? To determine this, somatostatin was infused along with basal replacement amounts of glucagon (0.65 ng/mg x min) and insulin (228 microU/kg x min) into five postabsorptive conscious dogs. After 1.5 h of basal hormone replacement, the glucagon infusion was terminated and a selective fall in the plasma glucagon level (75 +/- 6 to 30 +/- 4 pg/ml) occurred. This resulted in a drop in tracer (3H-glucose)-determined glucose production from 3.0 +/- 0.4 to 1.5 +/- 0.3 mg/kg x min. The plasma insulin level remained unchanged at 10 +/- 1 microU/ml throughout the experiment. Euglycemia (110 +/- 4 mg/dl) was maintained by exogenous glucose infusion. After 3 h of glucagon lack, restoration of the glucagon infusion returned the IRG level to control values (78 +/- 6 pg/ml) but restored glucose output only partially (42 +/- 9%), necessitating continued glucose infusion to preserve euglycemia. Repetition of the experiment in dogs whose pancreatic glucoregulatory feedback loops were broken surgically (two-stage pancreatectomy) rather than pharmacologically resulted in similar findings. It is concluded that glucagon deficiency of 3-h duration leads to a decrease, rather than an increase, in hepatic sensitivity to glucagon.

Differential time course of glucagon's effect on glycogenolysis and gluconeogenesis in the conscious dog.

The evanescence of glucagon's effect on glucose production (GP) is well documented, but it is unclear (1) whether this response involves both glycogenolysis and gluconeogenesis and (2) whether the liver becomes dependent on the increased glucagon level for the maintenance of a basal supply of glucose. To answer these questions, conscious overnight-fasted dogs were given somatostatin (0.8 microgram/kg . min) plus basal intraportal replacement amounts of insulin (273 microU/kg . min) and glucagon (0.65 ng/kg . min) for 2 h, after which the rate of glucagon infusion was increased fourfold for 3 h and then returned to basal for 1.5 h. GP was determined using a primed infusion of [3-3H]glucose, and gluconeogenesis (GNG) was estimated by determining the conversion rate of alanine and lactate to glucose. An increase in the plasma glucagon level from 55 to 206 pg/ml resulted in an initial 180% increase in GP, followed by a decline such that after 3 h of hyperglucagonemia GP was increased by only 41%. Contrary to overall GP, gluconeogenesis increased progressively throughout the hyperglucagonemic period, eventually reaching a rate 3 times basal. Restoration of the basal glucagon level (63 pg/ml) caused a marked decline in GP and GNG. In fact, GP fell to a level 29% below the initial control rate and consequently the plasma glucose level fell rapidly. The data suggest that (1) the downregulation of glucagon-stimulated GP is attributable to a decline in glycogenolysis and not gluconeogenesis, and (2) following adaptation to the hormone, the liver becomes dependent on the elevated glucagon concentration for the maintenance of basal glucose production.

Evidence for an intrahepatic contribution to the waning effect of glucagon on glucose production in the conscious dog.

We previously showed that infusion of glucagon at four times the basal rate into conscious dogs given somatostatin and basal replacement amounts of insulin caused hyperglycemia (217 15 mg/dl) for at least 3 h and an initial increment in hepatic glucose production of 5.5 0.8 mg/kg . min. After 3 h, however, the effect of hyperglucagonemia on glucose production had declined by 85%. The aim of the present study was to determine the importance of hyperglycemia in the "downregulation" of the action of glucagon. Six overnight-fasted conscious dogs were given somatostatin (0.8 microgram/kg . min) plus basal intraportal replacement amounts of insulin (263 microunits/kg . min) and glucagon (0.65 ng/kg . min). Hyperglycemia (276 12 md/dl) was established after 2 h by the infusion of exogenous glucose. The glucagon infusion rate was then increased fourfold 1 h later, so that the plasma glucagon level rose from 95 16 to 227 35 pg/ml. The glucose concentration was maintained at a fixed value despite the increase in glucagon by decreasing the glucose infusion rate by an amount equal to the increase in endogenous glucose production induced by the hormone. Glucose production was measured using a primed infusion of 3H-glucose. With the insulin (11 2 microunits/ml) and glucose levels fixed, the elevation in glucagon caused an initial increment of 5.1 0.7 mg/kg . min in glucose production which was followed by a fall of only 2.5 0.4 mg/kg . min (50%) over the next 3 hr. Thus, when the plasma glucagon level is raised fourfold under conditions in which insulin mobilization cannot occur, the effect of hyperglucagonemia on glucose production will be partially offset by the resulting hyperglycemia and partly inhibited by an hepatic factor(s).

Exercise-induced fall in insulin and increase in fat metabolism during prolonged muscular work.

The role of the exercise-induced fall in insulin in fat metabolism was studied in dogs during 150 min of treadmill exercise alone (controls) or with insulin clamped at basal levels by an intraportal infusion to prevent the normal fall in insulin concentration (ICs). To counteract the suppressive effect of insulin on glucagon release, glucagon was supplemented by an intraportal infusion in ICs. In all dogs, catheters were placed in a carotid artery and in the portal and hepatic veins for sampling and in the vena cava and the splenic vein for infusion purposes. Glucose levels were clamped in ICs to recreate the glycemic response evident in controls. In controls, insulin fell by 7 +/- 1 microU/ml but was unchanged from basal levels in ICs (0 +/- 2 microU/ml). Glucagon, norepinephrine, epinephrine, and cortisol rose similarly in controls and ICs. Arterial free-fatty acid (FFA) levels rose by 644 +/- 126 mu eq/L in controls but did not increase in ICs (-12 +/- 148 mu eq/L). Arterial glycerol levels rose by 337 +/- 43 and 183 +/- 19 microM in controls and ICs. Hepatic FFA delivery and fractional extraction increased by 17 +/- 3 and 0.06 +/- 0.02 mumol.kg-1.min-1, respectively, in controls. In ICs, hepatic FFA delivery increased by only 1 +/- 2 mumol.kg-1.min-1, whereas hepatic fractional extraction fell slightly (-0.03 +/- 0.03). Consequently, net hepatic FFA uptake rose by 4.8 +/- 1.5 mumol.kg-1.min-1 in controls but decreased slightly in ICs (-0.5 +/- 1.1 mumol.kg-1.min-1).(ABSTRACT TRUNCATED AT 250 WORDS)

Regulation of ketogenesis by epinephrine and norepinephrine in the overnight-fasted, conscious dog.

The effects on ketogenesis and lipolysis of a norepinephrine (0.04 microgram/kg-min), epinephrine (0.04 microgram/kg-min), or saline infusion were examined in the overnight-fasted, conscious dog. Plasma insulin and glucagon levels were maintained constant by means of a somatostatin infusion (0.8 microgram/kg-min) and intraportal replacement infusions of insulin and glucagon. In saline-infused dogs, plasma epinephrine (62 +/- 8 pg/ml), norepinephrine (92 +/- 29 pg/ml), blood glycerol (87 +/- 10 microM), and plasma nonesterified fatty acid (NEFA) (0.82 +/- 0.17 mM) levels did not change. Total blood ketone body levels tended to rise (62 +/- 10 to 83 +/- 11 microM) by 3 h as did total ketone body production (1.5 +/- 0.4 to 2.2 +/- 0.4 mumol/kg-min) over the same time interval. Norepinephrine infusion to produce plasma levels of 447 +/- 86 pg/ml caused a sustained 50% rise in glycerol levels (66 +/- 17 to 99 +/- 15 mumol/L, P less than 0.05) and 53% rise in nonesterified fatty acids (0.53 +/- 0.07 to 0.81 +/- 0.15 mumol/L, P less than 0.05). Total ketone body levels rose by 43% (51 +/- 8 to 73 +/- 10 mumol/L) and ketone body production rose by a similar proportion (1.5 +/- 0.2 to 2.2 +/- 0.3 mumol/kg-min), changes that did not differ significantly from control animals. A similar increment in plasma epinephrine levels (75 +/- 15 to 475 +/- 60 pg/ml) caused glycerol levels to rise by 82% (105 +/- 23 to 191 +/- 26 mumol/L) in 30 min, but this rise was not sustained and the level fell to 146 +/- 14 mumol/L by 120 min.(ABSTRACT TRUNCATED AT 250 WORDS)