title: Increased Expression of Pyloric ERβ Is Associated With Diabetic Gastroparesis in Streptozotocin-Induced Male Diabetic Rats.
abstract: BACKGROUND
  Gastroparesis is a significant co-morbidity affecting up to 50% of patients with diabetes and is disproportionately found in women. Prior studies have suggested that loss of interstitial cells of Cajal, hyperglycemia, and nitric oxide dysfunction are potential causes of gastroparesis. Since diabetic gastroparesis affects more women than men, we performed an exploratory study with a diabetic rat model to determine if sex hormone signaling is altered in those where gastroparesis develops.
  
  
  METHODS
  We injected male rats with streptozotocin (STZ) to model type I diabetes, as confirmed by blood glucose levels. Gastroparesis was determined by acetaminophen gavage and serum acetaminophen levels. Rats were grouped based on acetaminophen and blood glucose data: diabetic (DM), diabetic and gastroparetic (DM + GP), and control (CM). Serum levels of testosterone, estrogen, and insulin were determined as well as aromatase expression in pyloric tissue and serum. Androgen receptor and estrogen receptor α (ERα) and β (ERβ) were also measured in the pylorus.
  
  
  RESULTS
  Compared to CM, estrogen increased and testosterone decreased in both DM and DM + GP rats. Sex hormone levels were not different between DM and DM + GP. Serum aromatase was increased in DM and DM + GP rats; however, pyloric tissue levels were not significantly different from controls. ERα was unchanged and androgen receptor decreased in DM and DM + GP. ERβ was increased only in DM + GP animals.
  
  
  CONCLUSIONS
  Our study implicates increased pyloric ERβ in the development of gastroparesis in STZ-induced male diabetic rats. Increased serum aromatase is likely responsible for altered sex hormone levels. Our study supports the implication of sex hormone signaling in diabetic development and demonstrates a potential unique role for pyloric ERβ in male diabetic gastroparesis.
authors: Department of Clinical Investigation, William Beaumont Army Medical Center, 5005 N. Piedras Street, El Paso, TX 79920-5001, USA; These authors contributed equally to first authorship of this manuscript.
authors: Stephen
authors: S
authors: Crimmins
authors: Department of Clinical Investigation, William Beaumont Army Medical Center, 5005 N. Piedras Street, El Paso, TX 79920-5001, USA; These authors contributed equally to first authorship of this manuscript.
authors: Rebecca
authors: R
authors: Smiley
authors: Department of Clinical Investigation, William Beaumont Army Medical Center, 5005 N. Piedras Street, El Paso, TX 79920-5001, USA.
authors: Kerry
authors: K
authors: Preston
authors: Internal Medicine Clinic, San Antonio Military Medical Center, 3551 Roger Brooke Dr., San Antonio, TX 78219, USA.
authors: Amy
authors: A
authors: Yau
authors: Department of Internal Medicine, Texas Tech Health Science Center Paul L. Foster School of Medicine, 4800 Alberta Ave, El Paso, TX 79905-2709, USA.
authors: Richard
authors: R
authors: Mccallum
authors: Department of Clinical Investigation, William Beaumont Army Medical Center, 5005 N. Piedras Street, El Paso, TX 79920-5001, USA.
authors: Mohammed Showkat
authors: MS
authors: Ali
keywords: Diabetes; Estrogen; Gastroparesis