Somatostatin Receptor Antagonism Reverses Glucagon Counterregulatory Failure in Recurrently Hypoglycemic Male Rats

Endocrinology ◽  
2021 ◽  
Vol 162 (12) ◽  
Author(s):  
Emily G Hoffman ◽  
Mahsa Jahangiriesmaili ◽  
Erin R Mandel ◽  
Caylee Greenberg ◽  
Julian Aiken ◽  
...  
Keyword(s):  
Glycogen Content ◽  
Somatostatin Receptor ◽  
Male Rats ◽  
Vehicle Group ◽  
Hepatic Glycogen ◽  
Plasma Glucagon ◽  
Healthy Male ◽  
Sprague Dawley ◽  
Acute Hypoglycemia ◽  
Recurrent Hypoglycemia

Abstract Recent antecedent hypoglycemia is a known source of defective glucose counter-regulation in diabetes; the mechanisms perpetuating the cycle of progressive α-cell failure and recurrent hypoglycemia remain unknown. Somatostatin has been shown to suppress the glucagon response to acute hypoglycemia in rodent models of type 1 diabetes. We hypothesized that somatostatin receptor 2 antagonism (SSTR2a) would restore glucagon counterregulation and delay the onset of insulin-induced hypoglycemia in recurrently hypoglycemic, nondiabetic male rats. Healthy, male, Sprague–Dawley rats (n = 39) received bolus injections of insulin (10 U/kg, 8 U/kg, 5 U/kg) on 3 consecutive days to induce hypoglycemia. On day 4, animals were then treated with SSTR2a (10 mg/kg; n = 17) or vehicle (n = 12) 1 hour prior to the induction of hypoglycemia using insulin (5 U/kg). Plasma glucagon level during hypoglycemia was ~30% lower on day 3 (150 ± 75 pg/mL; P < .01), and 68% lower on day 4 in the vehicle group (70 ± 52 pg/mL; P < .001) compared with day 1 (219 ± 99 pg/mL). On day 4, SSTR2a prolonged euglycemia by 25 ± 5 minutes (P < .05) and restored the plasma glucagon response to hypoglycemia. Hepatic glycogen content of SSTR2a-treated rats was 35% lower than vehicle controls after hypoglycemia induction on day 4 (vehicle: 20 ± 7.0 vs SSTR2a: 13 ± 4.4 µmol/g; P < .01). SSTR2a treatment reverses the cumulative glucagon deficit resulting from 3 days of antecedent hypoglycemia in healthy rats. This reversal is associated with decreased hepatic glycogen content and delayed time to hypoglycemic onset. We conclude that recurrent hypoglycemia produces glucagon counterregulatory deficiency in healthy male rats, which can be improved by SSTR2a.

Diminished hormonal responses to exercise in trained rats

1977 ◽  
Vol 43 (6) ◽  
pp. 953-958 ◽  
Author(s):  
H. Galbo ◽  
E. A. Richter ◽  
J. J. Holst ◽  
N. J. Christensen
Keyword(s):  
Muscle Glycogen ◽  
Plasma Concentrations ◽  
Male Rats ◽  
Hepatic Glycogen ◽  
Plasma Glucagon ◽  
Glycogen Depletion ◽  
Hormonal Responses ◽  
Tissue Sensitivity ◽  
Glucagon And Insulin ◽  
Response To Exercise

Male rats (120 g) either were subjected to a 12-wk physical training program (T rats) or were sedentary controls (C rats). Subsequently the rats were killed at rest or after a 45- or 90-min forced swim. At rest, T rats had higher liver and muscle glycogen concentrations but lower plasma insulin. During exercise, blood glucose increased 60% in T rats but decreased 20% in C rats. Plasma glucagon and insulin concentrations did not change in T rats but plasma glucagon increased and insulin decreased markedly in C rats. Plasma epinephrine (90 min: range, 0.78–2.96 ng-ml-1, (T) vs. 4.42–15.67 (C)) and norepinephrine (90 min: 0.70–2.22 (T) vs. 2.50–6.10 (C)) were lower in T than in C rats. Hepatic glycogen decreased substantially and, as with muscle glycogen, the decrease was parallel in T and C rats. The plasma concentrations of free fatty acids were higher but lactate and alanine lower in T than in C rats. In trained rats the hormonal response to exercise is blunted partly due to higher glucose concentrations. In these rats adipose tissue sensitivity to catecholamines is increased, and changes in glucagon and insulin concentrations are not necessary for increased lipolysis and hepatic glycogen depletion during exercise.

Somatostatin Receptor II Antagonism Improves Glucagon Counterregulatory Responses to Recurrent Hypoglycemia in Male Sprague-Dawley Rats

Diabetes ◽  
2018 ◽  
Vol 67 (Supplement 1) ◽  
pp. 394-P
Author(s):  
MICHAEL RIDDELL ◽  
MAHSA JAHANGIRIESMAILI ◽  
ERIN R. MANDEL ◽  
CAYLEE A. GREENBERG ◽  
AOIBHE M. PASIEKA ◽  
...  
Keyword(s):  
Somatostatin Receptor ◽  
Sprague Dawley ◽  
Sprague Dawley Rats ◽  
Recurrent Hypoglycemia

scholarly journals Massive intestinal resection in rats fed up on glutamine: hepatic glycogen content valuation

2006 ◽  
Vol 43 (1) ◽  
pp. 55-58
Author(s):  
Ariney Costa de Miranda ◽  
Paulo Engler Pinto Jr. ◽  
Sidney Resende Ribeiro ◽  
Samson Henrique Bromberg ◽  
Fábio Pinatel Lopasso ◽  
...  
Keyword(s):  
Weight Loss ◽  
Small Intestine ◽  
Glycogen Content ◽  
Periodic Acid ◽  
Glycogen Synthesis ◽  
Intestinal Resection ◽  
Metabolic Effects ◽  
Male Rats ◽  
Hepatic Glycogen ◽  
Standard Diet

BACKGROUND: Glutamine has been widely used in treatment of small bowel syndrome and its metabolic effects on the small intestine are well known, however, it has been little studied its effects on hepatic metabolism under this condition. AIM: To verify through experimental model, a glutamine based supplemental diet, administered via oral to rats submitted to massive intestinal resection, evaluating weight evolution and hepatic glycogen content. MATERIAL AND METHODS: Male rats, Wistar, were allocated into three groups to undergo enterectomy. Following diets were applied: with glutamine (G group), without glutamine (NG group), and standard diet from the laboratory (R group). All animals had massive small intestine resection including ileocecal valve removal. After 20 days, all animals were sacrificed. The liver was removed to histological analysis by light microscopy. Slides were stained by periodic acid of Schiff with diastasis. RESULTS: All animals lost weight from the beginning to the end of experiment. Comparing weight loss average expressed in percentage, there was no difference statistically significant on this variance. In analyzed groups, the hepatic glycogen content did not differ statistically, in the histological method evaluated. CONCLUSION: Glutamine feeding via oral did not influence weight loss reduction of animal submitted to massive intestinal resection and did not stimulate glycogen synthesis and storage into hepatocytes.

scholarly journals Countering Opioid-induced Respiratory Depression in Male Rats with Nicotinic Acetylcholine Receptor Partial Agonists Varenicline and ABT 594

2020 ◽  
Vol 132 (5) ◽  
pp. 1197-1211
Author(s):  
Jun Ren ◽  
Xiuqing Ding ◽  
John J. Greer
Keyword(s):  
Respiratory Depression ◽  
Nicotinic Acetylcholine Receptors ◽  
Acetylcholine Receptors ◽  
Male Rats ◽  
Whole Body ◽  
Vehicle Group ◽  
Opioid Overdose ◽  
Sprague Dawley ◽  
Nicotinic Acetylcholine ◽  
Partial Agonists

Abstract Background Opioids can induce significant respiratory depression when administered as analgesics for the treatment of acute, postoperative, and chronic pain. There are currently no pharmacologic means of reversing opioid-induced respiratory depression without interfering with analgesia. Further, there is a growing epidemic of opioid overdose that could benefit from therapeutic advancements. The aim of this study was to test the ability of two partial agonists of α4β2 nicotinic acetylcholine receptors, varenicline (used clinically for smoking cessation) and ABT 594 (tebanicline, developed as an analgesic), to reduce respiratory depression induced by fentanyl, remifentanil, morphine, and a combination of fentanyl and diazepam. Methods Whole body plethysmographic recordings, nociception testing, and righting reflex testing were used to examine ventilation, analgesia, and sedation in adult male Sprague–Dawley rats. Results Pre-, co-, or postadministration of varenicline or ABT 594 did not alter baseline breathing but markedly reduced opioid-induced respiratory depression. Varenicline had no effect on fentanyl-induced analgesia and ABT 594 potentiated fentanyl-induced analgesia. Specifically, 10-min administration of fentanyl induced a decrease in respiratory rate to 43 ± 32% of control in vehicle group, which was alleviated by preadministration of varenicline (85 ± 14% of control, n = 8, P < 0.001) or ABT 594 (81 ± 36% of control, n = 8, P = 0.001). ABT 594 or varenicline with a low dose of naloxone (1 µg/kg), but not varenicline alone, partially reversed fentanyl-induced lethal apnea, but neither compound provided the very rapid and complete reversal of apnea achieved with high doses of naloxone (0.03 to 1 mg/kg). Administration of varenicline (n = 4, P = 0.034) or ABT 594 (n = 4, P = 0.034) prevented lethal apneas induced by the combination of fentanyl and diazepam. Conclusions Activation of α4β2 nicotinic acetylcholine receptors by varenicline and ABT 594 counters opioid-induced respiratory depression without interfering with analgesia. Editor’s Perspective What We Already Know about This Topic What This Article Tells Us That Is New

scholarly journals Recurrent Hypoglycemia Is Associated with Loss of Activation in Rat Brain Cingulate Cortex

Endocrinology ◽  
2012 ◽  
Vol 153 (4) ◽  
pp. 1908-1914 ◽  
Author(s):  
Paul Hurst ◽  
Alastair S. Garfield ◽  
Claire Marrow ◽  
Lora K. Heisler ◽  
Mark L. Evans
Keyword(s):  
Stress Responses ◽  
Cingulate Cortex ◽  
Brain Regions ◽  
Control Area ◽  
Sprague Dawley ◽  
Brain Areas ◽  
Sprague Dawley Rats ◽  
Brain Circuitry ◽  
Acute Hypoglycemia ◽  
Recurrent Hypoglycemia

A subset of people with diabetes fail to mount defensive counterregulatory responses (CRR) to hypoglycemia. Although the mechanisms by which this occurs remain unclear, recurrent exposure to hypoglycemia may be an important etiological factor. We hypothesized that loss of CRR to recurrent exposure to hypoglycemia represents a type of stress desensitization, in which limbic brain circuitry involved in modulating stress responses might be implicated. Here, we compared activation of limbic brain regions associated with stress desensitization during acute hypoglycemia (AH) and recurrent hypoglycemia (RH). Healthy Sprague Dawley rats were exposed to either acute or recurrent 3-d hypoglycemia. We also examined whether changes in neuronal activation were caused directly by the CRR itself by infusing epinephrine, glucagon, and corticosterone without hypoglycemia. AH increased neuronal activity as quantified by c-fos immunoreactivity (FOS-IR) in the cingulate cortex and associated ectorhinal and perirhinal cortices but not in an adjacent control area (primary somatosensory cortex). FOS-IR was not observed after hormone infusion, suggesting that AH-associated activation was caused by hypoglycemia rather than by CRR. Importantly, AH FOS-IR activation was significantly blunted in rats exposed to RH. In conclusion, analogous with other models of stress habituation, activation in the cingulate cortex and associated brain areas is lost with exposure to RH. Our data support the hypothesis that limbic brain areas may be associated with the loss of CRR to RH in diabetes.

scholarly journals The Effect of Single and Triple Testicular Biopsy Using Biopty Gun on Spermatogenesis in Pubertal Rats

Animals ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 1569
Author(s):  
Tomislav Šušnjar ◽  
Ivana Kuzmić Prusac ◽  
Ivan Švagelj ◽  
Anđela Jurišić ◽  
Tomislav Šušnjar ◽  
...  
Keyword(s):  
Sperm Count ◽  
Semen Analysis ◽  
Study Groups ◽  
Testicular Biopsy ◽  
Male Rats ◽  
Lower Percentage ◽  
Control Group ◽  
Sprague Dawley ◽  
Left Testis ◽  
Significant Difference

Background: The aim of this study was to compare consequences in single and triple testicular biopsy by biopty gun in pubertal rats using histological and immunohistochemical analysis. Methods: Thirty-two Sprague-Dawley male rats were used as the experimental model. The rats were randomly divided into three study groups. The rats from the first group (n = 12) received a single-biopsy of upper pole of the left testis, while the rats from the second group (n = 10) received triple-biopsy of upper and lower poles and lateral surface of left testis. The third group (n = 10) was a control group. On the eightieth day after the biopsy in all rats bilateral orchiectomy and funiculectomy were performed to obtain testicular tissue and sperm for analysis. The consequences of the puncture were observed by pathohistology, immunohistochemistry and semen analysis. Results: The results of the study showed lower percentage of sperm count (14.5 mill/mL vs. 16 mill/mL, p = 0.130), sperm motility (24.6% vs. 32.7%, p > 0.05), abnormal sperm (30% vs. 27%, p > 0.05), atrophic tubules (21% vs. 6%, p < 0.001), volume (1.7 mL vs. 2.28 mL, p < 0.01) and apoptotic index (1.56 vs. 1.19, p = 0.650) in the testes with a triple-biopsy compared to the testes with a single-biopsy. Semen analysis showed a borderline significant difference between the group with triple-biopsy where sperm count was lower than it in the control group (14.5 mill/mL vs. 17.5 mill/mL, p = 0.05). A single-biopsy has little effect on the testis, especially on overall fertility. A triple-biopsy showed higher degree of the testicular damage but without a significant impact on overall fertility. Semen analysis showed that single- and triple-biopsies did not have a significant effect on sperm count, motility and morphology. Conclusion: Biopty gun procedure is a cheap, simple and reliable method for testicular biopsy in rats without a significant effect on sperm count, motility and morphology.

scholarly journals Stamina-Enhancing Effects of Human Adipose-Derived Stem Cells

2021 ◽  
Vol 30 ◽  
pp. 096368972110354
Author(s):  
Eun-Jung Yoon ◽  
Hye Rim Seong ◽  
Jangbeen Kyung ◽  
Dajeong Kim ◽  
Sangryong Park ◽  
...  
Keyword(s):  
Physical Activity ◽  
Stem Cells ◽  
Locomotor Activity ◽  
Tissue Injury ◽  
Male Rats ◽  
Adipose Derived Stem Cells ◽  
Sprague Dawley ◽  
Serum Triglycerides

Stamina-enhancing effects of human adipose derived stem cells (hADSCs) were investigated in young Sprague-Dawley rats. Ten-day-old male rats were transplanted intravenously (IV) or intracerebroventricularly (ICV) with hADSCs (1 × 106 cells/rat), and physical activity was measured by locomotor activity and rota-rod performance at post-natal day (PND) 14, 20, 30, and 40, as well as a forced swimming test at PND 41. hADSCs injection increased the moving time in locomotor activity, the latency in rota-rod performance, and the maximum swimming time. For the improvement of physical activity, ICV transplantation was superior to IV injection. In biochemical analyses, ICV transplantation of hADSCs markedly reduced serum creatine phosphokinase, lactate dehydrogenase, alanine transaminase, and muscular lipid peroxidation, the markers for muscular and hepatic injuries, despite the reduction in muscular glycogen and serum triglycerides as energy sources. Notably, hADSCs secreted brain-derived neurotrophic factor (BDNF) and nerve growth factor in vitro, and increased the level of BDNF in the brain and muscles in vivo. The results indicate that hADSCs enhance physical activity including stamina not only by attenuating tissue injury, but also by strengthening the muscles via production of BDNF.

scholarly journals Comparison of Bax and Caspase-3 Protein Expression in Liver Cells following UVB Irradiation for 7 days and Treatment of Pimpinella alpina Molk during 7 and 15 days

2020 ◽  
Vol 19 (2) ◽  
pp. 296-303
Author(s):  
Eni Widayati ◽  
Taufiqurrachman Nasihun ◽  
Azizah Hikma Savitri ◽  
Nurina Tyagita
Keyword(s):  
Protein Expression ◽  
Caspase 3 ◽  
Medical Science ◽  
Liver Cells ◽  
Male Rats ◽  
Control Group ◽  
Sprague Dawley ◽  
Control Group Design ◽  
Uvb Irradiation ◽  
The Difference

Objective: The effect of Pimpinela alpina Molk (PaM) on decrease in Bax and Caspase-3 protein expression in liver cells apoptosis have been proven. However, the difference result between 7 and 15 days treatment duration of PaM need to be confirmed. This study aimed to confirm that treatment of PaM during 15 days is more effective decreasing Bax and Caspase-3 protein expression in liver cells following UVB irradiation. Methods: In the post test only control group design, 35 Sprague Dawley male rats, 300 gram body weight were divided into two arms, consisting of three groups respectively. First arm comprise Neg-7, PaM7-100, and PaM7-150. Second arm comprise Neg-15, PaM15-100, and PaM15-150. Nor-G was added as normal control neither exposed to UVB nor PaM treatment. In negative group was only radiated to UVB and PaM groups were exposed to UVB and treatment with 100, and 150 mg PaM per oral for 7 and 15 days respectively. At day 8 (first arm) and 16 (second arm), liver organ was taken and Bax and Caspase-3 protein expression assessed by Immunohistochemical staining method. Result: Post Hoc LSD analysis indicated that Bax and Caspase-3 protein expression in PaM15-100 and PaM15-150 was significant lower compared to that of Nor-G, PaM7-100, and PaM7-150, p < 0.05. Conclusion: Ttreatment of PaM with doses 100 and 150 mg for 15 days was better in decreasing Bax and Caspase-3 protein expression of liver cells following UVB irradiation. Bangladesh Journal of Medical Science Vol.19(2) 2020 p.296-303

Effect of Oral D-Tagatose on Liver Volume and Hepatic Glycogen Accumulation in Healthy Male Volunteers

2001 ◽  
Vol 33 (2) ◽  
pp. 257-267 ◽  
Author(s):  
Chris Boesch ◽  
Michael Ith ◽  
Bruno Jung ◽  
Karin Bruegger ◽  
Sidona Erban ◽  
...  
Keyword(s):  
Liver Volume ◽  
Hepatic Glycogen ◽  
Healthy Male ◽  
Glycogen Accumulation ◽  
Healthy Male Volunteers ◽  
Male Volunteers

Mesotheliomas and Proliferative Lesions of the Testicular Mesothelium Produced in Fischer, Sprague-Dawley and Buffalo Rats by Methyl(acetoxymethyl)nitrosamine (DMN-OAc)

1979 ◽  
Vol 16 (5) ◽  
pp. 574-582 ◽  
Author(s):  
J. J. Berman ◽  
J. M. Rice
Keyword(s):  
Body Weight ◽  
Tumor Cells ◽  
Mesothelial Cells ◽  
Male Rats ◽  
Sprague Dawley ◽  
Colloidal Iron ◽  
Microscopic Appearance ◽  
Intraperitoneal Dose ◽  
Single Focus

A single intraperitoneal dose of methyl(acetoxymethyl)nitrosamine (13 mg/kg body weight) given to 78 5-week-old male rats induced 25 mesotheliomas; two mesotheliomas were found in 67 control rats. All mesotheliomas arose from the peritesticular mesothelium and had a typical microscopic appearance of branching papillary fronds with a collagenous core covered by one or many layers of plump tumor cells. Cytoplasm of tumor cells contained material that reacted positively to a colloidal iron stain and was labile to hyaluronidase. In addition to frank mesotheliomas, 16 lesions, which we called atypical mesothelial proliferations. were found. These consisted of a single focus of plump mesothelial cells overlying an area of thick stroma. Often these foci included short, non-branched papillary projections above the surface of adjacent normal mesothelium. Twelve of the 16 lesions occurred in methyl(acetoxymethyl)nitrosamine-treated rats.

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