Central cholinergic regulation of pancreatic polypeptide secretion in conscious dogs

1997 ◽  
Vol 154 (2) ◽  
pp. 311-317 ◽  
Author(s):  
M Okita ◽  
A Inui ◽  
S Baba ◽  
M Kasuga

Abstract The secretion of pancreatic polypeptide (PP) is regulated by fluctuations in blood glucose concentrations and food intake, in which vagal-cholinergic mechanisms play an important role, especially for the cephalic phase of PP secretion. In this study, we examined whether central cholinergic mechanisms are also important for PP secretion by relaying information in the brain to the vagus nerve and the muscarinic cholinergic receptors in the pancreas. Atropine sulfate (20–200 μg) was administered into the lateral cerebral ventricle and its effects on the basal secretion of PP as well as the secretions stimulated by insulin-induced hypoglycemia (Actrapid MC, 0·25 U/kg) and a mixed meal (243 kcal) were studied in seven dogs. Intralateral cerebroventricular (ILV) atropine (100 and 200 μg) abolished the fluctuations in basal PP secretion without appearing in the plasma. Pretreatment with 20, 100, and 200 μg ILV atropine significantly decreased the PP response to insulin-induced hypoglycemia, with the integrated PP response to 58, 32, and 26% of that of controls respectively. Atropine (100 μg ILV) significantly reduced the postprandial PP secretion in both the cephalic and the gastrointestinal phases, whereas increased insulin and glucose levels were unaffected. Centrally administered atropine was able to suppress the basal secretion of PP as well as the secretions stimulated by hypoglycemia and food intake. These findings suggest that (1) the spontaneous release of PP is governed by an oscillating, central cholinergic tone, and (2) the stimulating PP secretion is, at least in part, regulated by the central cholinergic system. Journal of Endocrinology (1997) 154, 311–317

2005 ◽  
Vol 7 (3) ◽  
pp. 163-171 ◽  
Author(s):  
Martina Casella ◽  
Mike Hässig ◽  
Caudia E. Reusch

Home-monitoring of blood glucose concentrations has recently been introduced to owners. The objectives of this study were to investigate the feasibility of home-monitoring of blood glucose in diabetic cats by owners, the problems encountered and to compare glucose concentrations at home with those measured in the hospital. Twelve of 15 cat owners were able to generate glucose curves over the study period of 4 months. Most problems were related to restraining the cat, generating negative pressure with the lancing device and producing a blood drop. In the majority of cases, these problems could be resolved during the study. Blood glucose concentrations in the clinic tended to be lower than at home; some of the differences were significant. No association between tolerance of the procedure and blood glucose concentrations measured at home was found. We, therefore, assume that the lower glucose levels in the hospital were caused by lack of food intake. In 38% of cases, treatment based on hospital curves would have been different from that based on home curves. Home-monitoring appears to be a valuable tool in the management of cats with diabetes mellitus. One of its major advantages is that it enables frequent generation of blood glucose curves, which is of particular importance in cats that are difficult to regulate.


Author(s):  
Anna Katrina Jógvansdóttir Gradel ◽  
Jonas Kildegaard ◽  
Trine Porsgaard ◽  
Jens Lykkesfeldt ◽  
Hanne Hoffman Frølund Refsgaard

2021 ◽  
Vol 22 (1) ◽  
Author(s):  
Stijn Crutzen ◽  
Tessa van den Born-Bondt ◽  
Petra Denig ◽  
Katja Taxis

Abstract Background Hypoglycaemia is a common and potentially avoidable adverse event in people with type 2 diabetes (T2D). It can reduce quality of life, increase healthcare costs, and reduce treatment success. We investigated self-management issues associated with hypoglycaemia and self-identified causes of hypoglycaemia in these patients. Methods In this mixed methods study qualitative semi-structured interviews were performed, which informed a subsequent quantitative survey in T2D patients. All interviews were audio recorded, transcribed verbatim and coded independently by two coders using directed content analysis, guided by the Theoretical Domains Framework. Descriptive statistics were used to quantify the self-management issues and causes of hypoglycaemia collected in the survey for the respondents that had experienced at least one hypoglycaemic event in the past. Results Sixteen participants were interviewed, aged 59–84 years. Participants perceived difficulties in managing deviations from routine, and they sometimes lacked procedural knowledge to adjust medication, nutrition or physical activity to manage their glucose levels. Grief and loss of support due to the loss of a partner interfered with self-management and lead to hypoglycaemic events. Work ethic lead some participant to overexerting themselves, which in turn lead to hypoglycaemic events. The participants had difficulties preventing hypoglycaemic events, because they did not know the cause, suffered from impaired hypoglycaemia awareness and/or did not want to regularly measure their blood glucose. When they did recognise a cause, they identified issues with nutrition, physical activity, stress or medication. In total, 40% of respondents reported regular stress as an issue, 24% reported that they regularly overestimated their physical abilities, and 22% indicated they did not always know how to adjust their medication. Around 16% of patients could not always remember whether they took their medication, and 42% always took their medication at regular times. Among the 83 respondents with at least one hypoglycaemic event, common causes for hypoglycaemia mentioned were related to physical activity (67%), low food intake (52%), deviations from routine (35%) and emotional burden (28%). Accidental overuse of medication was reported by 10%. Conclusion People with T2D experience various issues with self-managing their glucose levels. This study underlines the importance of daily routine and being able to adjust medication in relation to more physical activity or less food intake as well as the ability to reduce and manage stress to prevent hypoglycaemic events.


2013 ◽  
Vol 218 (1) ◽  
pp. 25-33 ◽  
Author(s):  
Yusuke Seino ◽  
Takashi Miki ◽  
Wakako Fujimoto ◽  
Eun Young Lee ◽  
Yoshihisa Takahashi ◽  
...  

Glucose-induced insulin secretion from pancreatic β-cells critically depends on the activity of ATP-sensitive K+channels (KATPchannel). We previously generated mice lackingKir6.2, the pore subunit of the β-cell KATPchannel (Kir6.2−/−), that show almost no insulin secretion in response to glucosein vitro. In this study, we compared insulin secretion by voluntary feeding (self-motivated, oral nutrient ingestion) and by forced feeding (intra-gastric nutrient injection via gavage) in wild-type (Kir6.2+/+) andKir6.2−/−mice. Underad libitumfeeding or during voluntary feeding of standard chow, blood glucose levels and plasma insulin levels were similar inKir6.2+/+andKir6.2−/−mice. By voluntary feeding of carbohydrate alone, insulin secretion was induced significantly inKir6.2−/−mice but was markedly attenuated compared with that inKir6.2+/+mice. On forced feeding of standard chow or carbohydrate alone, the insulin secretory response was markedly impaired or completely absent inKir6.2−/−mice. Pretreatment with a muscarine receptor antagonist, atropine methyl nitrate, which does not cross the blood–brain barrier, almost completely blocked insulin secretion induced by voluntary feeding of standard chow or carbohydrate inKir6.2−/−mice. Substantial glucose-induced insulin secretion was induced in the pancreas perfusion study ofKir6.2−/−mice only in the presence of carbamylcholine. These results suggest that a KATPchannel-independent mechanism mediated by the vagal nerve plays a critical role in insulin secretion in response to nutrientsin vivo.


2017 ◽  
Vol 123 (2) ◽  
pp. 278-284 ◽  
Author(s):  
Yoichi Hatamoto ◽  
Ryoma Goya ◽  
Yosuke Yamada ◽  
Eichi Yoshimura ◽  
Sena Nishimura ◽  
...  

There is no consensus regarding optimal exercise timing for reducing postprandial glucose (PPG). The purpose of the present study was to determine the most effective exercise timing. Eleven participants completed four different exercise patterns 1) no exercise; 2) preprandial exercise (jogging); 3) postprandial exercise; and 4) brief periodic exercise intervention (three sets of 1-min jogging + 30 s of rest, every 30 min, 20 times total) in a random order separated by a minimum of 5 days. Preprandial and postprandial exercise consisted of 20 sets of intermittent exercise (1 min of jogging + 30 s rest per set) repeated 3 times per day. Total daily exercise volume was identical for all three exercise patterns. Exercise intensities were 62.4 ± 12.9% V̇o2peak. Blood glucose concentrations were measured continuously throughout each trial for 24 h. After breakfast, peak blood glucose concentrations were lower with brief periodic exercise (99 ± 6 mg/dl) than those with preprandial and postprandial exercise (109 ± 10 and 115 ± 14 mg/dl, respectively, P < 0.05, effect size = 0.517). After lunch, peak glucose concentrations were lower with brief periodic exercise than those with postprandial exercise (97 ± 5 and 108 ± 8 mg/dl, P < 0.05, effect size = 0.484). After dinner, peak glucose concentrations did not significantly differ among exercise patterns. Areas under the curve over 24 h and 2 h postprandially did not differ among exercise patterns. These findings suggest that brief periodic exercise may be more effective than preprandial and postprandial exercise at attenuating PPG in young active individuals. NEW & NOTEWORTHY This was the first study to investigate the effect of different exercise timing (brief periodic vs. preprandial vs. postprandial exercise) on postprandial glucose (PPG) attenuation in active healthy men. We demonstrated that brief periodic exercise attenuated peak PPG levels more than preprandial and postprandial exercise, particularly in the morning. Additionally, PPG rebounded soon after discontinuing postprandial exercise. Thus, brief periodic exercise may be better than preprandial and postprandial exercise at attenuating PPG levels.


2014 ◽  
Vol 29 (1) ◽  
pp. 27-31 ◽  
Author(s):  
Derrick Brown ◽  
Matthew Wyon

Ingesting quality carbohydrates has been shown to be essential for dancers. Given that most dance classes take place in the morning, it has been recommended that dancers eat a well-balanced breakfast containing carbohydrates, fats, and protein as a means of fueling this activity. The aim of this study was to determine the effect of a moderate glycemic index energy (MGI) bar or a fasting condition on dancers’ blood glucose levels and perceived pleasure-displeasure response during the first dance class of the day. In a randomized counterbalanced design, 10 female preprofessional dance students took their regular scheduled contemporary dance class, on four separate occasions. On each occasion, they consumed either a commercially prepared carbohydrate (CHO)-dense energy bar (47.3 g CHO) or water (FAST). Plasma glucose responses and pleasure-displeasure affect were measured before and at two time points during the class. Dancers who consumed the MGI bar had significantly greater peak blood glucose levels at all time points than those who fasted (p<0.05). Regarding affective state measures, participants who had breakfast had significantly greater pleasure scores than those who only ingested water (p<0.05). In conclusion, results suggest that CHO with an MGI value positively impacts blood glucose concentrations during a dance class. Further, we conclude that skipping breakfast can have an unfavorable effect on the pleasure-displeasure state of dancers. These findings highlight the impact of breakfast on how one feels, as well as the physiological and metabolic benefits of CHO as an exogenous energy source in dancers.


Author(s):  
Ricardo LÓPEZ-SOLÍS ◽  
Brenda Hildeliza CAMACHO-DÍAZ ◽  
Roberto CAMPOS-MENDIOLA ◽  
María Araceli ORTÍZ-RODRÍGUEZ

The aim of this review is to summarize the effects of carbohydrate consumption on endurance sports. Due to the promotion of physical activity by health authorities, participation in endurance sports is increasing. Regardless of the level, athletes look for ways to optimize their performance through training and nutrition. In consequence, research in the field of sports nutrition has focused on those strategies that can improve performance. Fatigue during prolonged exercise is associated with depletion of muscle glycogen and reduced blood glucose concentrations. Therefore, carbohydrate feeding during exercise has shown that it can improve capacity and performance, because it helps maintain blood glucose levels, as well as, increase carbohydrate oxidation rates and preserve glycogen, finding better results when are consumed multiple-tranportable carbohydrates for absortion (e.g., fructose and glucose), since in this way is possible to increase absorption rates, gastric emptying and fluid absorption, in addition to decrease gastrointestinal distress.


2021 ◽  
Vol 74 (9) ◽  
pp. 2277-2280
Author(s):  
Hanan Fawzi ◽  
Alaa Hussen Ali

The aim: To compared blood glucose concentrations after intravenous injection of dexamethasone in the pregnant and non-pregnant women under general anesthesia. Materials and methods: Eighty patients aged 18-50 years took part in the study (ASA class 1 and 2). Forty of patients were undergoing elective cesarean section under G/A and the other forty undergoing elective laparoscopic Cholecystectomy under G/A. Anesthesia was induced using IV anesthetic drugs (0.5mg/kg ketamine, sleeping dose of propofol up to 2mg/kg, muscle relaxant was 0.6 mg/kg rocuronium and maintained with isoflurane). All of patients have been injected with 0,1mg/kg dexamethasone intravenously, at induction of anesthesia, Blood glucose concentrations were measured at induction and then in 60min, 180min and in 360 min after injection of dexamethasone and results were compared between the groups; IV fluid added was normal saline (0.9%) during the study. Results: Regarding to blood glucose levels, we noticed that its level significantly increased over time and peaked in 180min after dexamethasone injection in both groups. The difference percentage between the lower reading (pre injection) and the upper reading (in 180min after) was 33.5% in pregnant woman and 46.2%for non-pregnant women, this difference was statistically significant relative to the pre injection, as this difference was lower in the pregnant women. In 360min after blood glucose level began to drop in both groups. After giving 0.1 mg/kg of dexamethasone, blood glucose level increased in both groups, but it was lower in pregnant women.


1997 ◽  
Vol 272 (3) ◽  
pp. R935-R939
Author(s):  
J. E. Schneider

Hyperphagia and anovulation are both triggered by prior food deprivation or other treatments that decrease intracellular availability of metabolic fuels in most species studied. Syrian hamsters fail to show compensatory hyperphagia, but do show anestrus in response to these energetic challenges. In the present experiments, we examined food intake, plasma glucose levels, and estrous cyclicity in Syrian hamsters in response to 2,5-anhydro-D-mannitol (2,5-AM), a fructose analog that is thought to trigger eating in rats by depleting intracellular levels of ATP. In experiment 1, female estrous cycling hamsters were treated with 100, 200, 400, or 800 mg/kg 2,5-AM or the vehicle by intraperitoneal injection. Food intake was measured 1, 2, 4, 8, and 24 h after treatment. There were no statistically significant increases in food intake in response to any dose of 2,5-AM. In experiment 2, blood samples were drawn at 0, 1, 3, 5, 7, and 25 h after hamsters were treated with 0 or 400 mg/kg 2,5-AM. 2,5-AM treatment resulted in a mild but significant decrease in plasma glucose levels similar to those seen in 2,5-AM-treated rats, suggesting that 2,5-AM has similar effects on fuel metabolism in rats and hamsters. In experiment 3, hamsters received 2,5-AM, 2,5-AM plus the fatty acid oxidation inhibitor methyl palmoxirate, or vehicle every 6 h over the first 48 h of the estrous cycle and were tested for indexes of estrous cyclicity at the end of the cycle. All hamsters showed normal estrous cycles, regardless of treatment. If 2,5-AM has similar metabolic consequences in rats and hamsters, the present results suggest that decreased intracellular levels of ATP and mild hypoglycemia do not increase food intake or inhibit estrous cyclicity in Syrian hamsters.


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