Biomedical subjects

G Tancrède

Publications and source records attributed to G Tancrède.

At least 19 recordsLinked to original sources

PubMed2001

Prior meal enhances the plasma glucose lowering effect of exercise in type 2 diabetes.

PURPOSE: To compare the changes in plasma glucose and insulin levels in response to 1 h of exercise performed at 60% of VO(2peak) either in the fasted state or 2 h after a standardized breakfast in subjects with type 2 diabetes. METHODS: Ten sedentary men with type 2 diabetes treated with oral agents and not under strict metabolic control were tested on two occasions (fasted and fed state) in a random order at a 1-wk interval. RESULTS: Plasma glucose was slightly but not significantly higher at the beginning of exercise performed in the fed state versus the fasted state (12.4 +/- 1.3 vs 11.1 +/- 1.1 mmol x L(-1) respectively; mean +/- SE, P = 0.06). However, after exercise, plasma glucose levels were much lower in the fed state (7.6 +/- 1.1 mmol x L(-1)) compared with the fasted state (10.0 +/- 1.0 mmol x L(-1); P = 0.009). Insulin levels were higher at the beginning of the exercise bout performed in the fed state (177 +/- 26 vs 108 +/- 19 pmol x L(-1); P < 0.05) and during exercise. Similar respiratory exchange ratio at identical workload indicated that the difference in glycemic response was not due to differences in whole body substrate utilization. Plasma concentrations of free fatty acids, glucagon, epinephrine, and norepinephrine were also similar during both experiments. CONCLUSIONS: One hour of aerobic exercise has a minimal impact on plasma glucose level when performed in fasted moderately hyperglycemic men with type 2 diabetes but induces an important decrease in plasma glucose level when performed 2 h after breakfast. Because glucose utilization increased similarly during exercise in both conditions, the higher insulin levels after the meal might have blunted glucose production, creating an imbalance between total glucose production and total peripheral utilization in the fed state in contrast to the fasted state.

Blood Glucose↗

PubMed2000

Impact of time interval from the last meal on glucose response to exercise in subjects with type 2 diabetes.

We evaluate the influence of the time interval from the last meal on the blood glucose response to exercise in men with type 2 diabetes. Nineteen men with type 2 diabetes participated in an exercise training program carried out at 60% of maximal oxygen uptake (VO2peak) for 1 h, 3 times a week. Capillary whole blood glucose was measured immediately before and after each exercise session, and the time interval from the last meal (breakfast, lunch, or dinner) was recorded. Seven time intervals were considered (fasted overnight and 0-1, 1-2, 2-3, 3-4, 4-5, and 5-8 h postmeal). A total of 1,045 exercise sessions were analyzed. There was no change in blood glucose levels when individuals were in the fasted state (mean +/- SE, 8.1 +/- 0.2 vs. 8.1 +/- 0.1 mmol/L; before vs. after, respectively). However, blood glucose decreased by 28 +/- 1% at 0-1 h, by 33 +/- 1% at 1-2 h, by 35 +/- 1% at 2-3 h, by 38 +/- 2% at 3-4 h, by 43 +/- 2% at 4-5 h, and by 23 +/- 3% at 5-8 h (all P < 0.001). These results demonstrate that 1 h of ergocycle exercise has no clinical impact on blood glucose when performed in the fasted state in men with type 2 diabetes, whereas a significant decrease in blood glucose should be expected when the same exercise is performed postprandially.

Adult↗

PubMed1996

Effect of physical training on mitochondrial function in skeletal muscle of normal and diabetic rats.

The study was designed to assess the impact of physical training on the oxidative phosphorylation rate (OPR) in mitochondria isolated from two different skeletal muscles of rats with or without chronic diabetes mellitus. Diabetes was induced by an intravenous injection of streptozotocin (50 mg/kg), and only animals with a blood glucose level between 14 and 22 mmol/L 1 week later were kept in the protocol. Exercise training was performed on a treadmill with a progressive 10-week program. Rats were killed by decapitation at the end of the training program, and mitochondria were isolated from the gastrocnemius and the red vastus lateralis muscles. When the data were expressed as per milligrams of protein, OPR was significantly depressed by diabetes mellitus in the mitochondria from each muscle; a similar negative impact also appeared to be produced by physical training in mitochondria isolated from the red vastus lateralis muscle. However, due to changes in mitochondrial protein yield between groups, the capacity to oxidize pyruvate and malate was also calculated per gram of muscle. Adenosine triphosphate (ATP) production rate appeared to be unaffected by diabetes but significantly increased by training in both muscles of diabetic and nondiabetic rats. This effect of training was not associated with any improvement in plasma glucose or insulin levels in diabetic animals. However, the large increase in plasma levels of beta-hydroxybutyric acid in sedentary diabetic rats was partly reversed by training (1,079 +/- 472 v 3,424 +/- 618 micromol, P < .001). These results suggest that the training-induced increase in the capacity of skeletal muscles to oxidize substrates and generate energy may also contribute to reduce the elevated plasma beta-hydroxybutyric acid levels observed in a state of insulin deficiency. This may have clinical relevance, since ketoacidosis remains a life-threatening event in insulin-dependent diabetic subjects.

3-Hydroxybutyric Acid↗

PubMed1993

Effect of adrenal demedullation and (or) physical training on glucose tolerance in the rat.

Physical training increases insulin sensitivity by mechanisms not yet fully understood. Because exercise also modulates adrenergic system activity, the present study was designed to ascertain whether the improved glucose homeostasis observed in trained rats is influenced by epinephrine secretion from the adrenal medullae. Male Wistar rats previously submitted to adrenal demedullation or sham operated were kept sedentary or trained on a treadmill over a 10-week period. An intravenous glucose tolerance test (IVGTT) was done 64 h after the last bout of exercise. Basal plasma glucose levels were reduced by physical training (p < 0.005) and by adrenal demedullation (p < 0.001). Adrenodemedullated rats had lower (p < 0.005) plasma glucose levels than sham-operated animals over the whole glucose tolerance curve. Trained animals had lower (p < 0.01) plasma glucose levels than sedentary rats throughout the IVGTT, except at 45 min. The glucose disappearance rate measured after the glucose bolus injection was increased by training (p < 0.05), whereas it was not modified by adrenal demedullation. Basal plasma insulin levels were reduced (p < 0.001) by physical training but unaffected by adrenal demedullation. During the IVGTT, adrenodemedullated rats had higher (p < 0.01) plasma insulin levels at 2, 4, and 6 min, whereas trained animals had lower (p < 0.05) plasma insulin levels throughout the test. Moreover, insulin in adrenodemedullated and trained rats had returned to basal levels at 30 min. The area under the curve for insulin was diminished by physical training (p < 0.001) but was not modified by adrenal demedullation.(ABSTRACT TRUNCATED AT 250 WORDS)

Adrenal Medulla↗

PubMed1993

Physical training attenuates phosphocreatine and long-chain acyl-CoA alterations in diabetic rat heart.

This study was designed to assess the effect of physical training on high-energy phosphate levels in the heart of diabetic rats. Diabetes was induced with streptozocin (50 mg/kg), and exercise training was carried out on a treadmill with a progressive 10-wk program. Plasma glucose levels at the end of the training program showed only a small improvement of the diabetic state in trained animals (21.7 +/- 1.3 vs. 24.4 +/- 0.8 mmol/l; P < 0.05). The lower heart rate observed in sedentary diabetic rats (279 +/- 6 vs. 356 +/- 5 beats/min; P < 0.001) was improved by physical training (301 +/- 8 beats/min; P < 0.05 vs. sedentary diabetics). Significantly lower phosphocreatine levels were found in sedentary diabetic rats (12.0 +/- 0.7 mumol/g dry wt) than in sedentary control rats (15.0 +/- 0.9 mumol/g dry wt; P < 0.05) but not in trained diabetic rats (13.7 +/- 0.7 mumol/g dry wt). ATP levels were not affected by diabetes but were increased by training. The increased long-chain acyl-CoA levels in sedentary diabetic rats (146 +/- 7 vs. 119 +/- 8 mumol/g dry wt in sedentary control rats; P < 0.05) were improved by training (138 +/- 6 mumol/g dry wt; P > 0.05 vs. sedentary control rats). These data indicate that the diminution in phosphocreatine levels observed in the heart tissue of chronically diabetic rats can be attenuated by an exercise training program.

Acyl Coenzyme A↗

PubMed1993

Captopril or conventional therapy in hypertensive type II diabetics. Three-year analysis.

The effects of long-term treatment with captopril and conventional therapy on albuminuria and metabolic parameters were compared in 74 hypertensive type II diabetics with normal serum creatinine. Patients were treated double-blind with either captopril monotherapy or combined with hydrochlorothiazide or therapy with metoprolol, hydrochlorothiazide, or both for 36 months. The treatment was titrated to achieve goal diastolic blood pressure of < or = 85 mm Hg. The reductions in blood pressures during treatment were similar in patients with (n = 21) and without (n = 53) microalbuminuria treated with either captopril or conventional therapy. No significant changes in albuminuria occurred in normoalbuminuric patients with either therapy. Although albuminuria fell in nearly all patients with microalbuminuria treated with captopril, it rose in eight of 12 patients on conventional therapy, with macroalbuminuria developing in two of them. Renal function was preserved by both types of treatment in both patient groups. Long-term treatment with either conventional therapy or captopril did not alter metabolic variables. We conclude that captopril alone or in combination decreases albuminuria and prevents the development of macroalbuminuria in hypertensive type II diabetics with persistent microalbuminuria. The renoprotective effect of this agent, however, remains to be demonstrated with longer term data on renal function. Aggressive antihypertensive treatment with either captopril or conventional therapy appears to be effective in preventing the onset of microalbuminuria in most normoalbuminuric patients. In contrast, with previous short-term studies, the use of converting enzyme inhibitors or conventional therapy did not cause adverse metabolic effects.

Aged↗

PubMed1992

Partial correction of impaired creatine kinase activity in diabetic rat heart by physical training.

The effect of physical training on total creatine kinase (CK), CK-MM, and CK-MB isoenzyme activity was studied in hearts of diabetic and control rats. Diabetes was induced with streptozotocin (50 mg/kg), and only rats with blood glucose levels between 14 and 22 mmol/L 1 week later were kept in the protocol. Exercise training was performed on a treadmill in a progressive 10-week program. Physical training did not induce any significant changes in plasma glucose or insulin levels in diabetic rats. Total CK, CK-MM, and CK-MB activity was decreased in diabetic rat heart by 27%, 22%, and 56%, respectively. Physical training did not induce any important changes in CK activity in heart of nondiabetic rats. However, in diabetic rat heart, training increased total CK activity by 13%, CK-MM activity by 12%, and CK-MB activity by 31%. We conclude that the decrease in cardiac CK activity observed in chronic experimental diabetes mellitus can be partly alleviated by a program of physical training. This may be one of the mechanisms whereby physical conditioning improves cardiac function in experimental diabetes.

Analysis of Variance↗

PubMed1991

Plasma epinephrine in chronically adrenodemedullated rats: lack of response to acute or chronic exercise.

Even if it is well established that epinephrine is a hormone originating from the adrenal medullae, the reappearance of circulating epinephrine has been reported in rats a few days after adrenodemedullation. To verify if the extra-adrenal tissue responsible for this epinephrine production can be stimulated, sham-operated or adrenodemedullated rats, either trained or kept sedentary, were submitted to an acute exercise stimulation test. Blood sampling was done before and after the test in precannulated rats for the determination of plasma epinephrine, norepinephrine, and corticosterone levels. Basal epinephrine levels were significantly reduced in trained and sedentary adrenodemedullated rats compared with their sham-operated counterparts. In response to exercise, there was no significant rise in epinephrine levels in both groups of adrenodemedullated rats. The norepinephrine levels in the basal state and in response to exercise were not altered by adrenodemedullation nor by physical conditioning. Basal corticosterone levels were similar between adrenodemedullated and sham-operated animals, either trained or kept sedentary. In response to exercise, corticosterone levels increased significantly in each group of rats but to a lesser extent in both groups of adrenodemedullated animals. These data indicate that the extra-adrenal epinephrine secretion that develops in the absence of adrenal medullae is not influenced by acute exercise nor by physical training.

Adrenal Medulla↗

PubMed1991

Comparative effects of converting enzyme inhibition and conventional therapy in hypertensive non-insulin dependent diabetics with normal renal function.

The effects of long-term reduction in blood pressure by the angiotensin converting enzyme inhibitor captopril, as single therapy or in combination with hydrochlorothiazide (HCTZ), were compared with those of metoprolol and/or hydrochlorothiazide in 91 hypertensive non insulin-dependent diabetics with normal renal function. Following a single-blind placebo run-in period of 4 weeks, treatments were assigned randomly in a double-blind fashion. During the study, weight and glycosylated hemoglobin remained elevated. After 9 months of treatment, blood pressure fell significantly (p less than 0.0001) in all treatment groups, with most patients achieving goal supine diastolic blood pressure of less than or equal to 85 mmHg. Whereas urinary albumin excretion (UAE) did not change in patients given metoprolol and/or HCTZ, captopril monotherapy (p = 0.0021) or captopril given in combination with HCTZ (p = 0.0002) decreased UAE without affecting glomerular filtration rate. These data are in favour of a renal beneficial effect of angiotensin converting enzyme inhibitors distinct from their effects on systemic blood pressure. Further studies are needed to determine whether this effect persists with longer treatment, and whether it would lead to better preservation of kidney function than other antihypertensive agents.

Aged↗

PubMed1990

Altered plasma free carnitine response to exercise in type 1 diabetic subjects.

The plasma carnitine response to prolonged exercise in 12 postprandial insulin-dependent diabetics was compared with that of eight normal controls. The diabetics reduced their morning dose of intermediate acting insulin and regular insulin to two-thirds and one-half, respectively. Insulin was injected subcutaneously into the abdominal wall. Exercise was performed on a treadmill for 90 min at 60% VO2 max. Respiratory exchange ratios (RER) decreased significantly (p less than 0.0001) during exercise in both the control and diabetic group. However, RER values were higher (p less than 0.05) in the diabetic group during most of the exercise period, corresponding to a significantly (p less than 0.05) lower proportion of the energy utilized from the oxidation of fat. In the diabetic group, mean plasma glucose at rest was 278 +/- 26 mg/dl, and decreased significantly (p less than 0.01) to 107 +/- 12 mg/dl after 90 min of exercise. In the control group, mean resting plasma glucose was 78 +/- 6 mg/dl, and dropped (p less than 0.05) to 67 +/- 3 mg/dl at 30 min of exercise. Thereafter, it showed no change. Mean resting plasma free insulin in the control group was lower compared to the diabetic group (10.2 +/- 2.0 vs 23.5 +/- 2.0 microU/ml, p less than 0.001). During exercise, insulin levels decreased significantly (p less than 0.01) in the control group while there was no change in the diabetic group. In both control and diabetic groups, percent basal total carnitine increased significantly (p less than 0.01) throughout exercise.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

PubMed1990

Physical training of moderate intensity improves survival rate of diabetic rats submitted to experimental myocardial infarction.

The present study was designed to compare the effect of three programs of exercise of different intensity on the survival rate of normal and streptozotocin-diabetic rats (60 mg/kg) submitted to acute experimental myocardial infarction. The animals were trained progressively on a treadmill once a day, five days per week for eight weeks at a 10 degree incline according to one of the following treadmill running programs: light (30 mins/day at 20 m/min), moderate (30 mins/day at 25 m/min) or heavy (60 mins/day at 25 m/min). Myocardial infarction was produced by left coronary artery ligation under ether anesthesia three days after the last bout of exercise. Successful ligation was demonstrated by elevated plasma creatine kinase MB isoenzyme levels 4 h later or by dye injection in rats with early death. In sedentary diabetic rats (n = 33), the early survival rate was decreased in comparison to sedentary controls (n = 22), although statistical significance was not reached, (30 versus 45%; P = 0.1952 by Fisher's exact test). These values were not significantly modified by light or heavy training in control (light n = 18, 61%; heavy n = 25, 56%) nor in diabetic animals (light n = 28, 32%; heavy n = 23, 39%). While the survival rate was not altered by moderate exercise in control animals (n = 26, 62%), it was greatly improved in diabetic rats (n = 23, 64%, P = 0.0108 versus sedentary diabetics). These data suggest that it is possible to improve the early survival rate of diabetic rats submitted to experimental myocardial infarction by a previous training program at a moderate level of exercise.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

PubMed1989

Diminished hypotensive response to isoproterenol in streptozotocin-diabetic rats.

1. The cardiovascular reactivity of streptozotocin-diabetic rats has been evaluated with isoproterenol (ISO), a strong beta-adrenergic agonist able to produce, at large dose, myocardial infarction. 2. In the basal state, diabetic rats presented significantly lower heart rate (P less than 0.001), a decreased systolic (P less than 0.05) and an unaltered diastolic blood pressure compared to non-diabetics. 3. Following ISO stimulation, the chronotropic response was similar in both groups of rats, while the fall in systolic and diastolic pressure was markedly reduced compared to those of non-diabetic rats (P less than 0.001). 4. These results suggest that the vasodilation capacity of diabetic rats is diminished.

Animals↗

PubMed1988

Exercise training improves early survival rate in diabetic rats submitted to acute coronary artery ligation.

This study was designed to test the hypothesis that the decreased early survival rate of diabetic rats submitted to acute experimental myocardial infarction could be improved by a previous training program. Male Wistar rats (+/- 200 g) were rendered diabetic with the i.v. injection of streptozotocin (45 mg/kg) but only those presenting one week later a tail-blood glucose value between 250-400 mg/dl were retained in the protocol. Diabetic and control rats were either kept sedentary or submitted to a progressive 10-week program of treadmill running. The left coronary artery was then ligated under ether anesthesia. Adequate occlusion was confirmed by an elevation of plasma CK-MB levels four hours later or by a toluidine blue injection technique in rats which died earlier. Since the first 20 minutes after such a procedure represents a most critical period for sudden death, the early survival rate was calculated for each group of rats and significance in differences was established with the Fisher's test. While the 27% early survival rate observed in sedentary diabetics was significantly lower (p = 0.02) than the 49% found in sedentary controls, this was completely alleviated by previous training in diabetic animals (50%; p = 0.018 vs sedentary diabetics and 0.623 vs sedentary controls). This beneficial effect of training was not found in nondiabetic animals.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

PubMed1988

Transient increase in basal insulin levels in severely diabetic rats submitted to physical training.

Physical training improves glucose homeostasis in rats with experimental diabetes mellitus. The present study has been designed to ascertain if this beneficial effect is maintained or lost after a few days of inactivity. Male Wistar rats were injected with streptozotocin (STZ, 50 mg/kg) and those presenting one week later a blood glucose value between 250 and 400 mg/dl were retained in the protocol and randomly assigned to a sedentary (n = 18) or trained group (n = 23). An I.V. glucose tolerance test (0.5 g/kg) was performed in previously cannulated rats 64 h (trained rats; n = 15) or 12 days (detrained rats, n = 8) after the last bout of exercise. In comparison with results obtained in their sedentary counterparts (419 +/- 15 mg/dl), basal glucose levels were significantly lower in trained (362 +/- 20; p less than 0.05), but not in detrained rats (429 +/- 15; NS). Similar differences in plasma glucose levels were observed after glucose loading, even though the glucose disappearance rate constant was not significantly improved by training. Furthermore, basal insulin levels were significantly higher (p less than 0.01) in trained than in sedentary rats (20 +/- 3 vs 12 +/- 2 microU/ml) but such a difference had disappeared in detrained rats (9 +/- 2 microU/ml). These results indicate that the training-induced improvement in glucose homeostasis of diabetic rats is a transient phenomenon which is associated with an increase in circulating insulin levels. This suggests that the beneficial effect of training is not due solely to enhanced insulin sensitivity.

Animals↗

PubMed1987

Acute diabetes mellitus does not impair survival rate in rats submitted to left coronary artery ligation.

This study was designed to assess whether the acute metabolic disturbances associated with diabetes mellitus of three-days duration could influence the survival of rats submitted to experimental myocardial infarction. Diabetes was induced with streptozotocin (50 mg/kg) in male Wistar rats and three days later left coronary artery ligation was performed in both control (n = 34) and diabetic (n = 31) animals. Diabetic rats had significant alterations in plasma levels of glucose (424 +/- 6 vs 143 +/- 3 mg/dL; p less than 0.001), insulin (10 +/- 1 vs 32 +/- 2 microU/mL; p less than 0.001) and free carnitine (37 +/- 2 vs 52 +/- 2 microM; p less than 0.001). There was no significant difference in the survival rate of diabetic animals, either early after coronary artery ligation (32 vs 42% at 20 min; p greater than 0.1) or later (21 vs 25% at 1 week; p greater than 0.1). This suggests that the increased mortality rate found in diabetic subjects suffering from myocardial infarction is due to some long-term changes associated with chronic diabetes mellitus rather than to the acute metabolic disturbances present at the time of this event.

Acute Disease↗

PubMed1986

Effect of physical training on norepinephrine turnover in tissues of normal and diabetic rats.

This study was designed to examine the influence of physical training on the norepinephrine turnover rate in heart, pancreas, liver, and gastrocnemius muscles of normal and diabetic male rats at rest. Diabetes was induced with the IV injection of streptozotocin (45 mg/kg) and physical training was done on a treadmill according to a ten-week program. Norepinephrine turnover rate of tissues was estimated by following over time the decay in the specific activity of norepinephrine after a single IV bolus of tritiated norepinephrine (30 microCi/kg). Plasma glucose, insulin, and glucagon levels were also measured at the time of death. Although training caused a reduction in the plasma glucose values of diabetic rats, no changes in norepinephrine turnover rate were observed after the conditioning program. On the other hand, diabetes was associated with a significant 30% to 40% decrease in the pancreatic norepinephrine turnover rate. It is concluded that the beneficial effects of physical training on diabetes mellitus cannot be explained by adaptive changes in the sympathetic nervous system activity and that further work will be necessary to elucidate the mechanism whereby streptozotocin diabetes diminishes the pancreatic norepinephrine turnover.

Animals↗

PubMed1986

Increased mortality rate in diabetic rats submitted to acute experimental myocardial infarction.

Diabetes mellitus is well known to increase the death rate after acute myocardial infarction in humans. The mechanisms of this adverse effect of diabetes, however, remain unknown. In the present study an animal model was developed in which the influence of diabetes on the survival rate after acute myocardial infarction could be studied in more detail. Male Wistar rats were rendered diabetic with streptozotocin (45 mg X kg-1 intravenously) and kept in the study if one week later their tail blood glucose concentration was between 13.9 and 22.2 mmol X litre-1 after a four hour fast. Ten weeks later they underwent acute left coronary artery ligation. In comparison with control rats (n = 30), diabetic rats (n = 32) had a higher mortality in the first 20 minutes after acute coronary artery ligation (78% vs 53%; p less than 0.05 by chi 2 test). Creatine kinase-MB isoenzyme activity tended to increase less in surviving diabetic rats than in their non-diabetic counterparts. Moreover, blood samples collected a few minutes before the surgical procedure showed that diabetic rats dying within the first 20 minutes (n = 25) had higher mean (SEM) plasma glucose concentrations (26.9(0.5) vs 23.4(1.2) mmol X litre-1; p less than 0.01) and lower mean(SEM) plasma insulin concentrations (20(1) vs 26(2) mU X litre-1; p less than 0.05) than those (n = 7) that survived that critical period.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

PubMed1985

Diminished glucagon response to epinephrine in physically trained diabetic rats.

The effect of physical training on glucose, insulin, and glucagon response to epinephrine was assessed in normal and diabetic rats. Male Wistar rats were injected with streptozocin (STZ, 45 mg/kg) and those presenting 1 wk later a blood glucose value between 250 and 400 mg/dl were retained in the protocol and randomly assigned to a sedentary or trained group. Similar studies were conducted in control animals. Physical training was done on a treadmill according to a 10-wk program. Epinephrine (0.75 microgram/kg/min) was infused intravenously (i.v.) in previously cannulated rats for 1 h and arterial blood samples obtained at 15-min intervals for glucose, insulin, and glucagon measurements. Pancreatic insulin and glucagon content was also determined. Basal glucose levels were significantly lower in trained than in sedentary diabetic rats (P less than 0.01). The hyperglycemic response to epinephrine was diminished by 19% and 23% in trained control and diabetic animals, respectively, with a faster return to baseline after stopping epinephrine infusion in both trained groups. Although in nondiabetic rats this could be related to some diminution in the suppressive effect of epinephrine on insulin secretion, this was not the case in diabetic animals. Moreover, while training did not modify epinephrine-induced glucagon response in control rats, the twofold greater (P less than 0.01) glucagon response observed in sedentary diabetic rats was restored to normal in trained diabetic rats. After stopping epinephrine infusion, glucagon levels dropped below the baseline in both groups of trained rats but not in their sedentary counterparts. These effects of training on glucagon response could not be explained by changes in pancreatic glucagon content.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗