Neuroscience Letter 1985 Jun 24;57(3):251-6
Demonstration of regional blood-brain barrier permeability in human brain. Landas S, Fischer J, Wilkin LD, Mitchell LD, Johnson AK, Turner JW, Theriac M, Moore KC. The brain of a 78-year-old woman with argyria was examined at autopsy. Silver nitrate deposition was observed in circumventricular organs (CVO) and in the paraventricular and supraoptic nuclei of the hypothalamus. These findings parallel animal experiments of other investigators and are the best demonstration so far of regional absence of the blood-brain barrier in humans. These observations demonstrate similarities between humans and other mammals of CVO anatomy, permeability to blood-borne agents, and perhaps neural connections between CVOs and magnocellular nuclei. PMID: 4034094 ******************************************************** : Microcirculation 2001 Apr;8(2):89-104 Regulation of blood-brain barrier permeability. Mayhan WG. Department of Physiology and Biophysics, University of Nebraska Medical Center, Omaha 68198-4575, USA. [email protected] The blood-brain barrier minimizes the entry of molecules into brain tissue. This restriction arises by the presence of tight junctions (zonulae occludens) between adjacent endothelial cells and a relative paucity of pinocytotic vesicles within endothelium of cerebral arterioles, capillaries, and venules. Many types of stimuli can alter the permeability characteristics of the blood-brain barrier. Acute increases in arterial blood pressure beyond the autoregulatory capacity of cerebral blood vessels, application of hyperosmolar solutions, application of various inflammatory mediators known to be elevated during brain injury, and/or activation of blood-borne elements such as leukocytes can produce changes in permeability of the blood-brain barrier. The second messenger systems that account for increases in permeability of the blood-brain barrier during pathophysiologic conditions, however, remain poorly defined. This review will summarize studies that have examined factors that influence disruption of the blood-brain barrier, and will discuss the contribution of various cellular second messenger pathways in disruption of the blood-brain barrier during pathophysiologic conditions. PMID: 11379794 ******************************************************** 1: Acta Neuropathol (Berl) 1983;60(1-2):92-8 Localization of exogenous silver in brain and spinal cord of silver exposed rats. Rungby J, Danscher G. Exogenous silver in brain and spinal cord sections from rats treated with Protargol, silver lactate or silver nitrate was visualized by physical development. The silver penetrated the blood-brain barrier and accumulated in neurones and glia. The distribution of silver in the CNS was heterogeneous. Even with low doses and short survival periods, silver was found to accumulate in large motoneurones in the brain stem and spinal cord and neurones in the cerebellar nuclei. Silver was only found in di- and telencephalic structures after extensive exposure. Silver distribution following oral silver lactate and silver nitrate treatment differed in that silver nitrate resulted in a relatively high content of silver in glia whereas deposition occurred preferentially in neurones following silver lactate treatment. Electron-microscopical studies showed that silver was located intracellularly in the lysosomes and extracellularly in basement membranes and elastic fibres of the vessels. PMID: 6880627 ************************************************ Acta Neuropathol (Berl) 1983;61(3-4):258-62 Neuronal accumulation of silver in brains of progeny from argyric rats. Rungby J, Danscher G. Using a photochemical method silver was demonstrated in the brains of 1-, 14-, and 45-day-old rats which had been exposed to silver on gestational days 18 and 19. In the brain tissue of new-born rats, silver was found in the lysosomes of neurons and astroglia. Minor changes in the anatomic distribution of silver were observed between days 1 and 45. The pattern seen at day 45 was identical to that observed in silver-exposed adults. At day 1, the choroid plexus and meninges were heavily loaded with silver both intra- and extracellularly. In particular, macrophage-like cells of the meningeal spaces contained large amounts of silver. In these structures, the silver had virtually disappeared by day 45. Silver was always seen in basement membranes of the cerebral vessels. PMID: 6650140 -- The silver-list is a moderated forum for discussion of colloidal silver. Instructions for unsubscribing may be found at: http://silverlist.org To post, address your message to: [email protected] Silver-list archive: http://escribe.com/health/thesilverlist/index.html List maintainer: Mike Devour <[email protected]>
