title: Effects of acute and chronic psychological stress on isolated islets' insulin release.
abstract: This study investigated the effects of acute and chronic psychological stress on glucose-stimulated insulin secretion from isolated pancreatic islets. Male Wistar rats were divided into two control and stressed groups; each further was allocated into fed and fasted groups. Stress was induced by communication box for one (acute), fifteen and thirty (chronic) days. After islet isolation, their number, size and insulin output were assessed. Plasma corticosterone level was determined. In fasted animals, acute stress increased basal and post stress plasma corticosterone level, while 30 days stress decreased it compared to day 1. In fed rats, acute stress increased only post stress plasma corticosterone concentration, however, after 15 days stress, it was decreased compared to day 1. Acute stress did not change insulin output; however, the insulin output was higher in the fed acutely stressed rats at 8.3 and 16.7 mM glucose than fasted ones. Chronic stress increased insulin output on day 15 in the fasted animals but decreased it on day 30 in the fed animals at 8.3 and 16.7 mM glucose. In the fasted control rats insulin output was lower than fed ones. In the chronic stressed rats insulin output at 8.3 and 16.7 mM glucose was higher in the fasted than fed rats. The number of islets increased in the fasted rats following 15 days stress. This study indicated that the response of the isolated islets from acute and chronically stressed rats are different and depends on the feeding status.
authors.affiliation: Neuroscience Research Center and Department of Physiology, Faculty of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran.
authors.forename: Homeira
authors.initials: H
authors.lastname: Zardooz
authors.affiliation: Endocrine Research Center, Research Institute for Endocrine Sciences, Shahid Beheshti University of Medical Sciences, Tehran, Iran.
authors.forename: Saleh
authors.initials: S
authors.lastname: Zahediasl
authors.affiliation: Department of Biology, Shahr-e-rey Branch, Islamic Azad University, Tehran, Iran.
authors.forename: Fatemeh
authors.initials: F
authors.lastname: Rostamkhani
authors.affiliation: Department of Immunology, Faculty of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran.
authors.forename: Babak
authors.initials: B
authors.lastname: Farrokhi
authors.affiliation: Neuroscience Research Center, Shahid Beheshti University of Medical Sciences, Tehran, Iran.
authors.forename: Shiva
authors.initials: S
authors.lastname: Nasiraei
authors.affiliation: Department of Pathology, Shahid Beheshti University of Medical Sciences, Tehran, Iran.
authors.forename: Behrang
authors.initials: B
authors.lastname: Kazeminezhad
authors.affiliation: Department of Pathology, Shahid Beheshti University of Medical Sciences, Tehran, Iran.
authors.forename: Roohollah
authors.initials: R
authors.lastname: Gholampour
keywords: corticosterone; insulin secretion; pancreatic islets area; pancreatic islets number; psychological stress