Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Neurosecretion”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 415 records · Page 23Linked to original sources
PubMed1985

Effects of diltiazem (a calcium antagonist) on neurosecretion and vascular responsiveness in hypertension.

The purpose of the present study was to analyse the mechanisms of the vasodepressive action of diltiazem (one of the Ca antagonists) in hypertension. The perfused mesenteric preparation was used in spontaneously hypertensive rats (SHR, Okamoto and Aoki, 7-9 weeks old) and age-matched Wistar-Kyoto rats (WKY). The effects of diltiazem on norepinephrine overflow from the sympathetic nerve endings and vascular responsiveness were investigated. Pressor responses to electrical nerve stimulation were inhibited dose-dependently by diltiazem. Norepinephrine overflow during periarterial nerve stimulation was also inhibited by diltiazem, and its suppression was significantly greater in SHR than in the age-matched WKY rats. Vasoconstrictor responses to exogenous norepinephrine were also reduced by diltiazem in both SHR and WKY rats. The inhibitory effects of diltiazem were more evident in SHR than in WKY rats. These results demonstrate that diltiazem could affect both pre- and postsynaptic sites of the resistance vessels and cause a decrease in electrically stimulated norepinephrine overflow from the sympathetic nerve endings, in addition to the direct effects on the responsiveness of the vascular smooth muscles. The marked reduction of the pressor responses and norepinephrine overflow by diltiazem in SHR might explain the Ca-dependency in the pathogenesis of hypertension.

Animals↗
PubMed1986

Effects of alpha-human atrial natriuretic peptides on neurosecretion and vascular responsiveness in spontaneously hypertensive rats.

Effects of alpha-human atrial natriuretic peptides (alpha-hANP) on the norepinephrine overflow from the sympathetic nerve endings and vascular responsiveness were investigated in the perfused mesenteric intestinal loop preparations from 7- to 9-week-old spontaneously hypertensive rats (SHR) and age-matched Wistar-Kyoto rats (WKY). Pressor responses to electrical nerve stimulation or exogenous norepinephrine were inhibited by alpha-hANP (3.4 X 10(-7) to 1.0 X 10(-6) mol/l), and norepinephrine overflow during the nerve stimulation was concomitantly suppressed by alpha-hANP. The pressor responses and norepinephrine overflow by nerve stimulation were greater in SHR than the age-matched WKY, while the inhibition of these responses by alpha-hANP was significantly less in SHR than in WKY. These results demonstrate that alpha-hANP could affect both pre- and post-synaptic sites of the resistance vessels, and less reduction in the pressor responses and norepinephrine overflow by alpha-hANP in SHR suggests insufficient regulation of adrenergic neurotransmission by cardiac peptide in hypertension.

Animals↗
PubMed1987

Canada goose posterior lobe pituicytes: seasonal ultrastructural changes in relation to axonal release of neurosecretion.

Changes in ultrastructure of the posterior lobe pituicytes during six phases (Spring premigratory, Spring postmigratory, breeding, moulting, Fall premigratory and Fall postmigratory) of the annual life cycle of the migratory Canada goose, were studied. Pituicyte nuclear volume in females was significantly greater than that in males during the Spring premigratory and moulting phases. In the Fall postmigratory phase, nuclear volume in males was greater than that in females. During Spring premigratory phase, the axonal endings in males contained fewer neurosecretory granules (NSG) than those in the Fall postmigratory phase. In females, however, the number of NSG was relatively more than that in males in the Spring premigratory phase but fewer in the moulting phase. Nuclear volume is correlated with pituicyte function in releasing NSG containing arginine vasotocin (AVT) from axonal endings. The significance of AVT release is discussed in relation to initiation of reproductive and migratory behaviour, and to osmotic and metabolic regulation.

Acclimatization↗
PubMed1985

[Neurosecretion and peptidergic synapses].

The notion of interneuronal neurosecretory synapses, proposed since 1954, was ignored until 1973; dating from this year the equivalent notion of peptidergic synapses becomes progressively recognized. The same holds true for the notion of intranervous transfer of neurosecretory substances, also proposed in 1954 and which (together with the former notion of interneuronal neurosecretory synapses) perfectly agrees with our present state of knowledge concerning peptidergic communications in the central nervous system.

Animals↗