Possible Interaction: Neuropeptide Y and Calcium Supplement

“In different types of neurone, activation of ~-adrenergic, GABAB, adenosine A~, dopamine, 5-HT,/~, 6and x-opioid, muscarinic acetylcholine, neuropeptide Y and somatostatin receptors results in inhibition of Ca 2÷ currents (for review see Tsien et al., 1988).”

“ NPY induced an intracellular calcium increase mainly mediated by Y2 and Y5 receptors in basal conditions.”

“In the presence of nifedipine (1 μM), whole-cell outward currents through Ca2+ -activated K+ channels were inhibited by NPY in a dose-dependent manner from 20 to 200 nM. A maximum inhibition to about 48% of the control current could be achieved.”

“These results suggest that NPY may potentiate vasoconstriction by promoting calcium entry through L-type voltage-dependent Ca2+-channels.”

“ NPY inhibits the stimulated secretion of CAs, however, its role in regulation of the genes encoding CA biosynthetic enzymes is not clear.”

“We conclude that NPY stimulates the CA biosynthetic pathway in the adrenal medulla and positive auto-regulation of NPY might be involved in this process.”

“ CA inhibited both basal and FOR + PMA induced production of NPY and DNA synthesis in a dose‐dependent manner: at 6 μM CA, basal NPY production was reduced by about 50%, FOR + PMA stimulated production of NPY and DNA synthesis were completely inhibited, and astrocytes were essentially eliminated.”

“The results suggested that NPY was co-released with CAs from chromaffin cells and then acted as a modulator on CA secretion.”

“6 The results show that, in rat mesenteric arterioles, NPY potentiates only the calcium entry blocker‐sensitive component of contraction induced by stimulation of α1‐adrenoceptors.”

“It is suggested that NPY enhances calcium entry induced by stimulation of α1‐adrenoceptors in this tissue.”

“Both NPY and the specific Y1 receptor ligand, [Leu31,Pro34]‐NPY, caused a rapid and transient increase in the concentration of free calcium in the cytoplasm as measured by the fluorescent probe, Fura‐2.”

“It is hypothesized that NPY increases the early (phasic) component of the contractile response by preferentially influencing release of intracellular calcium stores.”