Over high or low dietary protein levels depressed the growth, TOR signaling, apoptosis, immune and anti-stress of abalone Haliotis discus hannai
FISH & SHELLFISH IMMUNOLOGY
Authors: Ma, Shuoli; Guo, Yanlin; Sun, Li; Fan, Wenhao; Liu, Yue; Liu, Danni; Huang, Dong; Li, Xinxin; Zhang, Wenbing; Mai, Kangsen
Abstract
A 120-day feeding trial was conducted to investigate the effects of relative higher and lower dietary protein levels on the growth, immunity and anti-stress of abalone Haliotis discus hannai fed diets with 17.64% (low), 30.49% (normal) and 43.27% (high) of proteins, respectively. The results showed that compared with 30.49% of dietary protein, 17.64% and 43.27% of dietary protein levels significantly decreased the weight gain rate and the activities of a-amylase, trypsin, alanine aminotransferase and aspartate aminotransferase in the hepatopancreas and serum of abalone (P < 0.05). Abalone fed 30.49% of dietary protein had the highest activity of superoxidase, acid phosphatase, alkaline phosphatase, lysozyme and the total anti-oxidative capacity, and the lowest content of malondialdehyde in the serum and hepatopancreas (P < 0.05). The gene expressions of TOR, S6k, Bcl-2, I kappa B, Nf kappa B, TNF-alpha and Nrf2 were significantly up-regulated in the group with 30.49% of dietary protein (P < 0.05). Pathological abnormalities in hepatocyte cells of abalone were found in the groups with 17.64% and 43.27% of dietary protein. Meanwhile, accumulative mortalities of abalone after the Vibrio parahaemolyticus challenge test and heat stress test were significantly increased within these two groups (P < 0.05). In conclusion, the excessive (43.27) or deficient (17.64) dietary protein levels depressed the growth and immunity of abalone. Combined with the stress tests results, 17.63% or 43.27% of dietary protein contents are not recommended to the abalone facing the stress of vibriosis or high-water temperature (>= 28 degrees C).
Primary culture of the rat spinal dorsal horn: a tool to investigate the effects of inflammatory stimulation on the afferent somatosensory system
PFLUGERS ARCHIV-EUROPEAN JOURNAL OF PHYSIOLOGY
Authors: Leisengang, Stephan; Nuernberger, Franz; Ott, Daniela; Murgott, Jolanta; Gerstberger, Rudiger; Rummel, Christoph; Roth, Joachim
Abstract
One maladaptive consequence of inflammatory stimulation of the afferent somatosensory system is the manifestation of inflammatory pain. We established and characterized a neuroglial primary culture of the rat superficial dorsal horn (SDH) of the spinal cord to test responses of this structure to neurochemical, somatosensory, or inflammatory stimulation. Primary cultures of the rat SDH consist of neurons (43%), oligodendrocytes (35%), astrocytes (13%), and microglial cells (9%). Neurons of the SDH responded to cooling (7%), heating (18%), glutamate (80%), substance P (43%), prostaglandin E-2 (8%), and KCl (100%) with transient increases in the intracellular calcium [Ca2+](i). Short-term stimulation of SDH primary cultures with LPS (10 mu g/ml, 2 h) caused increased expression of pro-inflammatory cytokines, inflammatory transcription factors, and inducible enzymes responsible for inflammatory prostaglandin E-2 synthesis. At the protein level, increased concentrations of tumor necrosis factor-alpha (TNF alpha) and interleukin-6 (IL-6) were measured in the supernatants of LPS-stimulated SDH cultures and enhanced TNF alpha and IL-6 immunoreactivity was observed specifically in microglial cells. LPS-exposed microglial cells further showed increased nuclear immunoreactivity for the inflammatory transcription factors NF kappa B, NF-IL6, and pCREB, indicative of their activation. The short-term exposure to LPS further caused a reduction in the strength of substance P as opposed to glutamate-evoked Ca2+-signals in SDH neurons. However, long-term stimulation with a low dose of LPS (0.01 mu g/ml, 24 h) resulted in a significant enhancement of glutamate-induced Ca2+ transients in SDH neurons, while substance P-evoked Ca2+ signals were not influenced. Our data suggest a critical role for microglial cells in the initiation of inflammatory processes within the SDH of the spinal cord, which are accompanied by a modulation of neuronal responses.