Immunoreactivity

Neurotensin. This hormone has been isolated and characterized from acid—acetone extracts of bovine hypothalamus (118) on the basis of its hypotensive activity. Immunoreactive neurotensin is present in mammalian gut and is distributed throughout the central nervous system its highest concentration is in the hypothalamus and in the substantia gelatinosa of the spinal cord (119). Its overall brain distribution is not unlike that of enkephalin ( ) ... 

The class II cytokine receptor family includes receptors for interferon a/P (lEN a/P) and y (lENy) and IL-10. lEN-y immunoreactivity has been found in neurons in the hypothalamus, cerebral cortex, mammilary nuclei, and dorsal tegmentum. Astrocytes and microglia in vitro can be stimulated to express class II histocompatibiHty complex (MHC-II) antigens by lEN-y, which may be involved in the presentation of antigen to T-ceUs by astrocytes. Thus lEN-y may be critical in CNS-immune function and dysfunction especially in regard to neuronal and gHal apoptotic processes. 

Neuropeptide Y. Neuropeptide Y [82785 5-3] (NPY) (255) is a 36-amiao acid peptide that is a member of a peptide family including peptide YY (PYY) [81858-94-8, 106338-42-5] (256) and pancreatic polypeptide (PPY) [59763-91-6] (257). In the periphery, NPY is present in most sympathetic nerve fibers, particulady around blood vessels and also in noradrenergic perivascular and selected parasympathetic nerves (66). Neurons containing NPY-like immunoreactivity ate abundant in the central nervous system, particulady in limbic stmctures. Coexistence with somatostatin and NADPH-diaphorase, an enzyme associated with NO synthesis, is common in the cortex and striatum. 

Dynorphin may also influence nociception at the spinal level. The levels of prodynorphin mRNA and immunoreactive dynorphin increase in the chronic inflammatory arthritic model (158). Dynorphin also inhibits morphine or P-endorphin-induced analgesia in naive animals and enhances analgesia in tolerant animals, indicating that this peptide may have a regulatory role in opioid analgesia (159). This effect does not appear to be mediated by a classical opioid receptor, since des-tyrosine dynorphin, which does not bind to opioid receptors, also antagonizes morphine analgesia (160). 

In the CNS, calbindin D28k is widely expressed in a subpopulation of neurons distinct from those immunoreactive for parvalbumin or calretinin. 

Extrahypothalamic OX-B-like immunoreactivity, reminiscent to that of CRF, has been described in clustered GABAergic neuronal populations, in the lateral division of central nucleus ofthe amygdala, the bednucleus of the stria terminalis, and in the hippocampus. Moreover, ectopic expression of preproorexin mRNA in the gut, ependymal cells, neuroblastomas, and of orexin receptors in adrenal gland, cancer and hematopietic stem cells suggests yet unexplored roles of orexins as paracrine factors controlling blood-brain barrier, and tumor or stem cell function. 

High amounts of somatostatin are found in the CNS, the peripheral nervous system, the gut and the endocrine pancreas whereas the kidneys, adrenals, thyroid, submandibular glands, prostate and placenta produce rather low amounts. In particular, the hypothalamus, all limbic structures, the deeper layers of the cerebral cortex, the striatum, the periaqueductal central grey and all levels of the major sensoty pathway are brain areas that are especially rich in somatostatin. Eighty percent of the somatostatin immunoreactivity in the hypothalamus is found in cells of the anterior periventricular nucleus (Fig. 1, [1]). The gut 5 cells of the mucosa and neurons, which are intrinsic to the submucous and... 

Immunoreactive Forms of Circulating Parathyroid Hormone in Primary and Ectopic Hyperparathyroidism". J. Clin. Invest. (1974), 175-181. 

Fig. 8.1 Rostrocaudal neuroanatomical distribution of CCR5-immunoreactivity in the telencephalon, diencephalon and mesencephalon using a CCR5 antibody (Santa Cruz Biotechnology, Santa Cruz, CA, USA). Regions corresponding to pictures are depicted in coronal diagrams taken from the Paxinos and Watson (1998). (a, b) M Motor cortex, (c, d) CPu caudate putamen (striatum), (e,t)SID substantia innominata dorsal part, (g, h) GP globus pallidus, (i, j)Me medial amygdaloid...

Treatment of neurons with dualtropic X4R5 gpl20 has been shown to induce cytochrome c accumulation and caspase 9, 8, and 3 activation (Garden et al. 2002). Incidentally in the same studies, activated caspase 3 immunoreactivity was found in the brains of neuroAIDS patients. Furthermore, caspase 3 activation was found to be involved in the synaptic and dendritic injury (Garden et al. 2002). Chronic dendritic disrnption has been correlated with the severity of HIV-related dementia (as reviewed in Ellis et al. 2007). 

Some ethical and practical concerns may be overcome by the use of porcine rather than human foetal cells and their potential is on trial. Certainly xenotransplants can survive in the human brain partly because it does not show the same immunoreactivity as the rest of the body but recipients will still require some immunosuppressant drugs. Attempts are also being made, with some success, to expand mesencephalic dopamine... 

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