Among schoolchildren in northern Sweden, where mite allergy is uncommon, furry animals were the primary perennial sensitizers. Asthma was associated with higher levels of component sensitization, and sensitization to more than one component from the same animal conferred the greatest risk.
Synthetic fragments of galanin 1-29 were administered intraventricularly or into the paraventricular nucleus of the hypothalamus for analysis of the critical amino acid sequence necessary to stimulate feeding behavior in rats. Galanin 1-29 and galanin fragment 1-16 significantly increased feeding at doses of 6 nmol microinjected into the lateral ventricles and 1 nmol microinjected into the hypothalamus. There was no significant effect of D-TRP2 galanin 1-16 microinjected into the hypothalamus, and no significant effect of galanin fragments 1-9, 10-20, 12-29, 17-29, or 21-29 microinjected intraventricularly, on food consumption. Synthetic fragments of galanin 1-29 were assayed for displacement of 125I-galanin 1-29 binding to rat hypothalamic membranes. The efficacies of the galanin fragments in the feeding paradigm were consistent with the relative affinities of these fragments for the hypothalamic galanin receptor in equilibrium binding experiments. The first 16 N-terminal amino acids appear to contain galanin agonist activity on increasing food consumption and to bind to the galanin receptor in the rat hypothalamus.
Many children diagnosed as wheat allergic have outgrown their allergy and are unnecessarily on a wheat-free diet. The levels of IgE-ab to wheat gluten-derived components correlated well with wheat challenge outcome and severity.
The galanin N-terminal fragment [galanin-(1-16) The 29-amino-acid-long C-terminal amidated peptide galanin (GAL) (1) has been shown to be widely distributed in the central nervous system of mammals (2-6). GAL-like immunoreactivity has been localized, among other brain regions, in the septal area (4-8) where GAL coexists with acetylcholine in rat (7) and monkey (9) in a subpopulation of cholinergic cell bodies projecting to the hippocampus. and equilibrium binding studies with 1251I-labeled GAL (125I-GAL) have shown a high density of putative high-affinity GAL receptors in the ventral part of the hippocampus (13).In the ventral, but not in the dorsal, hippocampus GAL has been shown to inhibit, in a dose-dependent manner, the release of acetylcholine both in vitro and in vivo (12). A possible role for GAL as presynaptic modulator of the cholinergic function in the ventral hippocampus has been suggested by a recent electrophysiological study (14) and a behavioral study (15). Interactions between acetylcholine and GAL in the ventral hippocampus are not restricted to presynaptic sites but also involve actions that are considered postsynaptic (16) such as the GAL-mediated inhibition of the muscarinic agonist-stimulated breakdown of inositol phospholipids in the ventral hippocampus (17) and GAL inhibition of acetylcholine on a t-maze memory task in ventral forebrain lesioned rats (33).Previous studies carried out on intestinal smooth muscle showed the importance of the N-terminal portion of GAL for biological activity (18,19). Furthermore, N-terminal GAL fragments and analogs were able to mimic the effects of GAL on the pancreatic 83-cell line Rin m 5F, inhibiting forskolinstimulated cAMP production and insulin release (20).In this study, we focus our attention on the structureactivity relationship for the N terminus of GAL at receptors in the ventral hippocampus of the rat. Using equilibrium binding and autoradiographic techniques, we compare the synthetic N-terminal fragment GAL-(1-16) with rat GAL-(1-29) for its ability to displace 1251I-GAL from its receptors.GAL-(1-16) is also tested for its ability to inhibit the scopolamine-induced acetylcholine release in vivo and carbacholstimulated inositol phospholipid breakdown in a slice preparation from the rat ventral hippocampus. The importance of [Trp2] in the activity of the N-terminal fragment is examined.
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