Gastrin stimulates renal dopamine production by increasing the renal tubular uptake of L-DOPA
This study aimed to determine the mechanisms of the interaction between gastrin and dopamine and tested the hypothesis that gastrin produced in the kidney increases renal dopamine production to keep blood pressure within the normal range. We show that in human and mouse renal proximal tubule cells (hRPTCs and mRPTCs, respectively), gastrin stimulates renal dopamine production by increasing the cellular uptake of l-DOPA via the l-type amino acid transporter (LAT) at the plasma membrane. The uptake of l-DOPA in RPTCs from C57Bl/6J mice is lower than in RPTCs from normotensive humans. l-DOPA uptake in renal cortical slices is...
Source: AJP: Endocrinology and Metabolism - December 31, 2016 Category: Endocrinology Authors: Jiang, X., Zhang, Y., Yang, Y., Yang, J., Asico, L. D., Chen, W., Felder, R. A., Armando, I., Jose, P. A., Yang, Z. Tags: Research Article Source Type: research
The role of dietary fat in obesity-induced insulin resistance
The objective of this study was to determine the specific contribution of dietary fat rather than total caloric intake to the development of obesity-associated insulin resistance. We used an intragastric feeding method to overfeed excess calories from a low-fat diet (and an isocalorically matched high-fat diet) through a surgically implanted gastric feeding tube to generate obesity in wild-type mice followed by hyperinsulinemic-euglycemic clamp studies to assess the development of insulin resistance. We show that overfeeding a low-fat diet results in levels of obesity similar to high-fat diet feeding in mice. However, desp...
Source: AJP: Endocrinology and Metabolism - December 11, 2016 Category: Endocrinology Authors: Lackey, D. E., Lazaro, R. G., Li, P., Johnson, A., Hernandez-Carretero, A., Weber, N., Vorobyova, I., Tsukomoto, H., Osborn, O. Tags: Articles Source Type: research
Chronic hyperprolactinemia evoked by disruption of lactotrope dopamine D2 receptors impacts on liver and adipocyte genes related to glucose and insulin balance
We studied the impact of high prolactin titers on liver and adipocyte gene expression related to glucose and insulin homeostasis in correlation with obesity onset. To that end we used mutant female mice that selectively lack dopamine type 2 receptors (D2Rs) from pituitary lactotropes (lacDrd2KO), which have chronic high prolactin levels associated with increased body weight, marked increments in fat depots, adipocyte size, and serum lipids, and a metabolic phenotype that intensifies with age. LacDrd2KO mice of two developmental ages, 5 and 10 mo, were used. In the first time point, obesity and increased body weight are mar...
Source: AJP: Endocrinology and Metabolism - December 11, 2016 Category: Endocrinology Authors: Luque, G. M., Lopez-Vicchi, F., Ornstein, A. M., Brie, B., De Winne, C., Fiore, E., Perez-Millan, M. I., Mazzolini, G., Rubinstein, M., Becu-Villalobos, D. Tags: Articles Source Type: research
Presleep protein ingestion does not compromise the muscle protein synthetic response to protein ingested the following morning
Protein ingestion before sleep augments postexercise muscle protein synthesis during overnight recovery. It is unknown whether postexercise and presleep protein consumption modulates postprandial protein handling and myofibrillar protein synthetic responses the following morning. Sixteen healthy young (24 ± 1 yr) men performed unilateral resistance-type exercise (contralateral leg acting as a resting control) at 2000. Participants ingested 20 g of protein immediately after exercise plus 60 g of protein presleep (PRO group; n = 8) or equivalent boluses of carbohydrate (CON; n = 8). The subsequent morning participants...
Source: AJP: Endocrinology and Metabolism - December 11, 2016 Category: Endocrinology Authors: Wall, B. T., Burd, N. A., Franssen, R., Gorissen, S. H. M., Snijders, T., Senden, J. M., Gijsen, A. P., van Loon, L. J. C. Tags: Articles Source Type: research
Divergent functions of endotrophin on different cell populations in adipose tissue
In conclusion, our study provides a new perspective on the effect of endotrophin in abnormal lipid accumulation and a mechanistic insight into the roles played by adipocytes and a variety of other cell types in AT in shaping the unhealthy microenvironment upon endotrophin treatment. (Source: AJP: Endocrinology and Metabolism)
Source: AJP: Endocrinology and Metabolism - December 11, 2016 Category: Endocrinology Authors: Zhao, Y., Gu, X., Zhang, N., Kolonin, M. G., An, Z., Sun, K. Tags: Call for Papers Source Type: research
Quenching the thirst for hunger
(Source: AJP: Endocrinology and Metabolism)
Source: AJP: Endocrinology and Metabolism - December 11, 2016 Category: Endocrinology Authors: Lee, P. Tags: Editorial Source Type: research
Corrigendum
(Source: AJP: Endocrinology and Metabolism)
Source: AJP: Endocrinology and Metabolism - November 30, 2016 Category: Endocrinology Tags: Corrigendum Source Type: research
Fourth-ventricle leptin infusions dose-dependently activate hypothalamic signal transducer and activator of transcription 3
Previous studies have shown that very low-dose infusions of leptin into the third or the fourth ventricle alone have little effect on energy balance, but simultaneous low-dose infusions cause rapid weight loss and increased phosphorylation of STAT3 (p-STAT3) in hypothalamic sites that express leptin receptors. Other studies show that injecting high doses of leptin into the fourth ventricle inhibits food intake and weight gain. Therefore, we tested whether fourth-ventricle leptin infusions that cause weight loss are associated with increased leptin signaling in the hypothalamus. In a dose response study 14-day infusions of ...
Source: AJP: Endocrinology and Metabolism - November 30, 2016 Category: Endocrinology Authors: Harris, R. B. S., Desai, B. N. Tags: Articles Source Type: research
Adult expression of PGC-1{alpha} and -1{beta} in skeletal muscle is not required for endurance exercise-induced enhancement of exercise capacity
Exercise has been shown to be the best intervention in the treatment of many diseases. Many of the benefits of exercise are mediated by adaptions induced in skeletal muscle. The peroxisome proliferator-activated receptor gamma coactivator-1 (PGC-1) family of transcriptional coactivators has emerged as being key mediators of the exercise response and is considered to be essential for many of the adaptions seen in skeletal muscle. However, the contribution of the PGC-1s in skeletal muscle has been evaluated by the use of either whole body or congenital skeletal muscle-specific deletion. In these models, PGC-1s were never pre...
Source: AJP: Endocrinology and Metabolism - November 30, 2016 Category: Endocrinology Authors: Ballmann, C., Tang, Y., Bush, Z., Rowe, G. C. Tags: Articles Source Type: research
Differential effects of bisphenol A diglicydyl ether on bone quality and marrow adiposity in ovary-intact and ovariectomized rats
Bisphenol A diglycidyl ether (BADGE), a PPAR2 antagonist, has been shown to inhibit marrow adipogenesis and promote bone formation in intact animals. We investigated the impact of BADGE on a new and more clinically relevant physiological model, the ovariectomized (OVX) rat model. Forty female Wistar rats were divided into four treatment groups for 12 wk (n = 10/group): sham+vehicle, sham+BADGE, OVX+vehicle, and OVX+BADGE. Postmortem analyses included MRI, micro-CT, serological test, histomorphometry, biomechanical tests, RT-PCR, and Western blot. Overall, OVX induced a sequential marrow fat expansion accompanied by bone de...
Source: AJP: Endocrinology and Metabolism - November 30, 2016 Category: Endocrinology Authors: Li, G., Xu, Z., Hou, L., Li, X., Li, X., Yuan, W., Polat, M., Chang, S. Tags: Articles Source Type: research
Activation of {beta}3-adrenoceptors increases in vivo free fatty acid uptake and utilization in brown but not white fat depots in high-fat-fed rats
Activation of brown adipose tissue (BAT) and browning of white adipose tissue (WAT) present potential new therapies for obesity and type 2 diabetes. Here, we examined the effects of β3-adrenergic stimulation on tissue-specific uptake and storage of free fatty acids (FFA) and its implications for whole body FFA metabolism in diet-induced obese rats using a multi-radiotracer technique. Male Wistar rats were high fat-fed for 12 wk and administered β3-agonist CL316,243 (CL, 1 mg·kg–1·day–1) or saline via osmotic minipumps during the last 3 wk. The rats were then fasted and acutely infused wi...
Source: AJP: Endocrinology and Metabolism - November 30, 2016 Category: Endocrinology Authors: Warner, A., Kjellstedt, A., Carreras, A., Böttcher, G., Peng, X.-R., Seale, P., Oakes, N., Linden, D. Tags: Call for Papers Source Type: research
Corrigendum
(Source: AJP: Endocrinology and Metabolism)
Source: AJP: Endocrinology and Metabolism - November 14, 2016 Category: Endocrinology Tags: Corrigendum Source Type: research
Prolonged sitting negatively affects the postprandial plasma triglyceride-lowering effect of acute exercise
In conclusion, prolonged sitting over 2–4 days was sufficient to amplify PPL, which was not attenuated by acute exercise, regardless of energy balance. This underscores the importance of limiting sitting time even in people who have exercised. (Source: AJP: Endocrinology and Metabolism)
Source: AJP: Endocrinology and Metabolism - November 14, 2016 Category: Endocrinology Authors: Kim, I.-Y., Park, S., Chou, T.-H., Trombold, J. R., Coyle, E. F. Tags: Articles Source Type: research
Caspase-1 deficiency promotes high-fat diet-induced adipose tissue inflammation and the development of obesity
Caspase-1 is a cysteine protease responsible for the processing of the proinflammatory cytokine interleukin-1β and activated by the formation of inflammasome complexes. Although several investigations have found a link between diet-induced obesity and caspase-1, the relationship remains controversial. Here, we found that mice deficient in caspase-1 were susceptible to high-fat diet-induced obesity with increased adiposity as well as normal lipid and glucose metabolism. Caspase-1 deficiency clearly promoted the infiltration of inflammatory macrophages and increased the production of C-C motif chemokine ligand 2 (CCL2) ...
Source: AJP: Endocrinology and Metabolism - November 14, 2016 Category: Endocrinology Authors: Kimura, H., Karasawa, T., Usui, F., Kawashima, A., Endo, Y., Kobayashi, M., Sadatomo, A., Nakamura, J., Iwasaki, Y., Yada, T., Tsutsui, H., Kasahara, T., Takahashi, M. Tags: Articles Source Type: research
Zinc finger protein 407 overexpression upregulates PPAR target gene expression and improves glucose homeostasis in mice
The peroxisome proliferator-activated receptor (PPAR) family of nuclear receptors is central to the pathophysiology and treatment of metabolic disease through the receptors' ability to regulate the expression of genes involved in glucose homeostasis, adipogenesis, and lipid metabolism. However, the mechanism by which PPAR is regulated remains incompletely understood. We generated a transgenic mouse strain (ZFP-TG) that overexpressed Zfp407 primarily in muscle and heart. Transcriptome analysis by RNA-Seq identified 1,300 differentially expressed genes in the muscle of ZFP-TG mice, among which PPAR target genes were signific...
Source: AJP: Endocrinology and Metabolism - November 14, 2016 Category: Endocrinology Authors: Charrier, A., Wang, L., Stephenson, E. J., Ghanta, S. V., Ko, C.-w., Croniger, C. M., Bridges, D., Buchner, D. A. Tags: Articles Source Type: research
