Vasoactive intestinal peptide increases intracellular calcium in astroglia: synergism with alpha-adrenergic receptors.

In type I astrocytes from rat cerebral cortex, vasoactive intestinal peptide (VIP) at concentrations below 1 nM evoked an increase in intracellular calcium ion concentration. This response, however, was observed in only 18% of the astrocytes examined. alpha-Adrenergic stimulation with phenylephrine or norepinephrine also resulted in an intracellular calcium response in these cells and the threshold sensitivity of astrocytes to phenylephrine was vastly different from cell to cell.

Adrenalectomy decreases vasoactive intestinal peptide mRNA levels in the rat suprachiasmatic nucleus.

Vasoactive intestinal peptide (VIP) concentrations were shown to be regulated by adrenal steroids. Therefore, we investigated whether adrenal steroids affect VIP mRNA levels, which would suggest an effect on VIP mRNA expression. Adrenalectomy performed on adult male rats resulted in a significant decrease in VIP mRNA in the hypothalamus (from 10.

A decomposition product of a contaminant implicated in L-tryptophan eosinophilia myalgia syndrome affects spinal cord neuronal cell death and survival through stereospecific, maturation and partly interleukin-1-dependent mechanisms.

The L-tryptophan eosinophilia myalgia syndrome (L-TRP-EMS), an inflammatory syndrome characterized by eosinophilia, myalgias, perimyositis, fasciitis and neuropathies, occurred in epidemic proportions in the United States in the summer and fall of 1989. The neuropathic clinical features in L-TRP EMS are complex and mixed. In the present study, one of the impurities most highly associated with development of L-TRP EMS, 1,1'-ethylidenebis[L-tryptophan] (EBT), and two of its diastereoisomeric breakdown products, were compared for evidence of neurotoxicity in vitro.

HIV envelope protein-induced neuronal damage and retardation of behavioral development in rat neonates.

Cognitive and motor impairment are common symptoms among patients infected with the human immunodeficiency virus (HIV), including children who suffer neurological deficits and are frequently developmentally impaired. The HIV envelope protein, gp120, which has been shown to be toxic to neurons in culture, is shed in abundance by infected cells, and thus may play a significant role in the neuropathology of AIDS. To test this possible mechanism, neonatal rats were injected systemically with purified gp120 and the following consequences were observed: (1) radiolabeled gp120 and toxic fragments thereof were recovered in brain homogenates; (2) dystrophic changes were produced in pyramidal neurons of cerebral cortex; (3) retardation was evident in developmental milestones associated with complex motor behaviors.

VIP-mRNA is increased in hypertensive rats.

Vasoactive intestinal peptide (VIP) is a potent vasodilator. We therefore set out to investigate VIP-gene expression in spontaneous hypertensive rats. By quantitative in situ hybridization histochemistry as well as by RNA blot hybridization experiments we discovered a significant increase in VIP transcripts in the brains of those hypertensive rats.

Lactation elevates vasoactive intestinal peptide messenger ribonucleic acid in rat suprachiasmatic nucleus.

Vasoactive intestinal peptide (VIP) has been suggested to play a role in lactation; indeed several studies implied that VIP induces the release of PRL in the pituitary. Quantitative RNA studies from our laboratory show an increase in the VIP messenger RNA (mRNA) content in the hypothalamus of lactating rats. The purpose of this investigation is to determine which hypothalamic neurons are increasing the expression of VIP.

Sequential expression in the nervous system of c-myb and VIP genes, located in human chromosomal region 6q24.

Vasoactive intestinal peptide (VIP) is a major neuropeptide involved in multiple functions such as vasodilation, smooth-muscle relaxation, sweat secretion, gastrointestinal peristalsis, pancreatic function, and brain activity. In view of the multiple roles associated with VIP, it is important to understand its gene regulation. We have recently isolated the human VIP gene and determined its structure.

The gene encoding vasoactive intestinal peptide is located on human chromosome 6p21----6qter.

Vasoactive intestinal peptide (VIP) is a regulatory neuropeptide involved in a wide variety of functions, among them vasodilation, smooth muscle relaxation, sweat secretion, gastrointestinal peristalsis, and pancreatic function. A deficient VIP-innervation of sweat glands was recently described as a possible pathogenic factor in sweating of cystic fibrosis (CF) patients. To investigate a possible role for a defective VIP-gene in cystic fibrosis, we have used a panel of rodent-human hybrid cells, retaining defined complements of human chromosomes to localize the VIP-gene to the human chromosome region 6p21----6qter.