Brain-derived neurotrophic factor in higher vertebrate pancreas: immunolocalization in glucagon cells

Abstract

Brain-derived neurotrophic factor (BDNF) is a growth factor that belongs to the group of neurotrophins. Its amino acid sequences are well conserved during vertebrate phylogenesis. Pancreatic tissue has recently been reported to be one of the physiological sources of BDNF in humans and mice. In this study we investigated the presence and localization of BDNF immunoreactivity (IR) in the pancreas of three species of higher vertebrates: mouse, duck and lizard. BDNF IR was present in the islets and in single cells scattered in the exocrine parenchyma of all three species examined. Using double staining, BDNF IR was seen to be colocalized with glucagon IR in all the species studied. There was a total overlap of BDNF and glucagon IR in duck and lizard pancreas, and partial overlap in mouse pancreas. Our findings suggest that, as well as the primary structure, the presence and pattern of distribution of BDNF in higher vertebrates is also well conserved. Moreover, the abundance of BDNF IR in the pancreas of the species studied leads us to the suggestion that these neurotrophins could regulate the function of pancreatic innervation and/or act on pancreatic cells in a paracrine/autocrine fashion.

Effects of castration on the expression of brain-derived neurotrophic factor (BDNF) in the vas deferens and male accessory genital glands of the rat

“…BDNF, like other neurotrophins, is known to be secreted, stored and released by neuroendocrine cells (Goodman et al 1996;Heymach et al 1996). BDNF immunoreactivity and/or BDNF mRNA have been previously reported in the pituitary and in gastrointestinal endocrine cells (Conner et al 1996;Hannestad et al 1998;Amoureux 1999;Bonini et al 2001;Lucini et al 2003;Maruccio et al 2004). Neuroendocrine cells in the prostate have been well documented (Vittoria et al 1990;Angelsen et al 1998;Rodriguez et al 2003;Arrighi et al 2004) but their role in prostate physiology is poorly understood.…”

Effects of moderate‐ and high‐intensity chronic exercise on brain‐derived neurotrophic factor expression in fast and slow muscles

“…Brain‐derived neurotrophic factor (BDNF), a member of the neurotrophin family, plays a key role in the development, survival, and function of neuronal tissues . Accumulating evidence suggests that neurotrophins play a more widespread role than originally thought, and they are now being studied across multiple tissue systems .…”

Cellular localization of GDNF and its GFRalpha1/RET receptor complex in the developing pancreas of cat

“…2001); (3) neurotrophin 3 and its specific receptor TrkC in buffalos of different ages (Lucini et al. 2003a); (4) brain‐derived neurotrophic factor (BDNF) in various vertebrate species (Lucini et al. 2003b).…”

“…The latter consideration is further confirmed by previous studies. Glucagon cells were seen to express: (1) neurotrophin 3 in man (Ohta et al 1997); (2) TrkB, the specific BDNF receptor, in teleost fish (Lucini et al 2001); (3) neurotrophin 3 and its specific receptor TrkC in buffalos of different ages (Lucini et al 2003a); (4) brain-derived neurotrophic factor (BDNF) in various vertebrate species (Lucini et al 2003b).…”