Regulation of rCBF by intracortical vasoactive intestinal polypeptide-containing neurons

1987 ◽  
Vol 67 (1) ◽  
pp. 93-96 ◽  
Author(s):  
Toru Itakura ◽  
Hideyoshi Yokote ◽  
Takashi Okuno ◽  
Yutaka Naka ◽  
Kazuo Nakakita ◽  
...  
Keyword(s):  
Blood Flow ◽  
Blood Vessels ◽  
Vasoactive Intestinal Polypeptide ◽  
Content Type ◽  
Intimate Association ◽  
The Mean ◽  
Immunohistochemical Studies ◽  
Hydrogen Clearance ◽  
Intestinal Polypeptide

✓ The role of intracortical vasoactive intestinal polypeptide (VIP)-containing neurons in the regulation of cortical blood flow was investigated in rats by immunohistochemical and hydrogen clearance methods. Immunohistochemical studies revealed an intimate association between intracortical VIP-containing neurons and small blood vessels. Intracortical injection of a VIP solution (10−5 M) produced significantly higher blood flow in the treated cortex (mean ± standard error of the mean: 46.2 ± 4.0 ml/100 gm/min) than in the untreated cortex (36.9 ± 2.4 ml/100 gm/min). These data suggest that intracortical VIP-containing neurons produce dilatation of intracortical blood vessels.

scholarly journals Innervation of the pancreas by substance P, enkephalin, vasoactive intestinal polypeptide and gastrin/CCK immunoractive nerves.

1979 ◽  
Vol 27 (9) ◽  
pp. 1283-1284 ◽  
Author(s):  
L I Larsson
Keyword(s):  
Blood Flow ◽  
Insulin Secretion ◽  
Substance P ◽  
Blood Vessels ◽  
Vasoactive Intestinal Polypeptide ◽  
Pancreatic Blood Flow ◽  
Major Site ◽  
Site Of Action ◽  
Immunocytochemical Studies ◽  
Intestinal Polypeptide

Immunocytochemical studies habe shown that many peptides which profoundly affect the endocrine and exocrine functions of the pancreas are localized to neurons. In the cat, such peptidergic nerves appear to innervate ganglia, islets and blood vessels of the pancreas, whereas their contributions to exocrine cells are minor. Our studies suggest that pancreatic ganglia represent one major site of action of the peptides and that, in addition, nerves containing the vasoactive intestinal polypeptide and gastrin/CCK-related peptides profoundly affect pancreatic blood flow and insulin secretion, respectively.

A role of the central catecholamine neuron in cerebral circulation

1986 ◽  
Vol 65 (3) ◽  
pp. 370-375 ◽  
Author(s):  
Hideyoshi Yokote ◽  
Toru Itakura ◽  
Kunio Nakai ◽  
Ichiro Kamei ◽  
Harumichi Imai ◽  
...  
Keyword(s):  
Blood Flow ◽  
Cerebral Blood Flow ◽  
Blood Vessels ◽  
Cerebral Circulation ◽  
Intracerebral Injection ◽  
Neuron System ◽  
Content Type ◽  
6 Hydroxydopamine ◽  
Catecholamine Neuron

✓ The effect of the central catecholaminergic neurons on the cerebral microcirculation was investigated by means of a unilateral intracerebral injection of 6-hydroxydopamine (6-OHDA) which produced the degeneration of catecholamine (CA) nerve terminals. Subsequent observation with CA histofluorescence revealed an absence of CA fibers in the vicinity of the 6-OHDA injection site. A significant increase in regional cerebral blood flow (rCBF), measured by the hydrogen clearance method, was demonstrated in the CA-depleted cortex under normocapnia as compared with rCBF in the control cortex (CA-depleted cortex 47.0 ± 2.8 ml/100 gm/min; control cortex 38.5 ± 3.5 ml/100 gm/min; p < 0.005). The increased rCBF in the cortex treated with 6-OHDA was suppressed by the iontophoretic replacement of noradrenaline (NA) to the CA-depleted cortex. An iontophoretic replacement of 10−5 M dopamine (DA) mildly suppressed the increased rCBF in the 6-OHDA-treated cortex. The CO2 reactivity in the CA-depleted cortex was significantly lower than that of the control cortex (CA-depleted cortex 2.13% ± 0.67%/mm Hg; control cortex 3.53% ± 0.70%/mm Hg). No change was noticeable in the cerebral glucose metabolism in the CA-depleted cortex in an investigation based on tritiated (3H)-deoxyglucose uptake. It is suggested that the 6-OHDA-induced change in cerebral blood flow (CBF) is not secondary to alterations in cerebral metabolic rate, and that the central NA neuron system innervating intraparenchymal blood vessels regulates CBF through a direct vasoconstrictive effect on the cerebral blood vessels. The central DA neuron system may modulate the cerebral circulation as a mild vasoconstrictor.

5-Hydroxytryptamine innervation of vessels in the rat cerebral cortex

1985 ◽  
Vol 62 (1) ◽  
pp. 42-47 ◽  
Author(s):  
Toru Itakura ◽  
Hideyoshi Yokote ◽  
Hiroshi Kimura ◽  
Ichiro Kamei ◽  
Kazuo Nakakita ◽  
...  
Keyword(s):  
Blood Vessels ◽  
Nerve Fibers ◽  
Ultrastructural Observation ◽  
Intracerebral Injection ◽  
Neuron System ◽  
Content Type ◽  
Carbon Dioxide Reactivity ◽  
Immunohistochemical Techniques ◽  
Immunohistochemical Studies ◽  
Hydrogen Clearance

✓ The role of the central 5-hydroxytryptamine (5-HT) neuron system in cerebral microcirculation of the rat was examined by immunohistochemical and hydrogen clearance methods. Immunohistochemical studies demonstrated 5-HT-immunoreactive nerve fibers along intraparenchymal blood vessels (arterioles, capillaries, and venules). Ultrastructural observation revealed that 5-HT-immunoreactive terminal boutons (0.3 to 1.0 µm in diameter) made contact with the basement membrane of the capillaries. After an intracerebral injection of 5,7-dihydroxytryptamine (5,7-DHT), a neurotoxin to the 5-HT neuron system, no 5-HT-immunoreactive nerve fibers were found around the injection site with immunohistochemical techniques. With the hydrogen clearance method, the 5,7-DHT-injected cortex showed no significant change in regional cerebral blood flow (rCBF) in the presence of normocapnia, but a significant increase in rCBF with hypercapnia, compared with the untreated cortex. These facts strongly suggest that the central 5-HT neuron system has an important role in carbon dioxide reactivity of the cerebral blood vessels.

Reduction of blood flow in the adenohypophysis of rats by bromocriptine

1985 ◽  
Vol 63 (1) ◽  
pp. 120-124 ◽  
Author(s):  
Andras A. Kemeny ◽  
Jan A. Jakubowski ◽  
Emil Pasztor ◽  
Anthony A. Jefferson ◽  
Richard Wojcikiewicz
Keyword(s):  
Blood Pressure ◽  
Blood Flow ◽  
Wistar Rats ◽  
Content Type ◽  
Selective Effect ◽  
Arterial Blood ◽  
Male Wistar Rats ◽  
The Mean ◽  
Hydrogen Clearance ◽  
Fine Print

✓ The possibility that bromocriptine has a selective effect on blood flow in the adenohypophysis was examined in rats. Twenty-four anesthetized male Wistar rats underwent measurement of blood flow using the hydrogen clearance method. Intravenous injection of 50 µg/kg bromocriptine reduced the blood flow in both the medial and lateral parts of the adenohypophysis to about 70% of the baseline value. Simultaneously measured cerebral cortical and white matter flows were unchanged. Similar results were obtained following administration of a higher dose (500 µg/kg) of bromocriptine. This phenomenon cannot be attributed to the decrease in blood pressure. The course of change in blood flow in the medial and lateral adenohypophysis did not follow that of the mean arterial blood pressure, and the alteration of blood pressure remained within the limits of autoregulation in the adenohypophysis. The results indicate that bromocriptine is capable of reducing blood flow selectively in the pituitary region. This mechanism may contribute to the clinical usefulness of this drug.

scholarly journals Development-Dependent Plasticity in Vasoactive Intestinal Polypeptide Neurons in the Infralimbic Cortex

2021 ◽  
Vol 2 (1) ◽  
Author(s):  
Stuart A Collins ◽  
Ipe Ninan
Keyword(s):  
Sex Differences ◽  
Anxiety Disorders ◽  
Vasoactive Intestinal Polypeptide ◽  
Cortical Plasticity ◽  
Male Mice ◽  
Infralimbic Cortex ◽  
Membrane Excitability ◽  
Gabaergic Transmission ◽  
Intestinal Polypeptide

Abstract The onset of several neuropsychiatric disorders including anxiety disorders coincides with adolescence. Consistently, threat extinction, which plays a key role in the regulation of anxiety-related behaviors, is diminished during adolescence. Furthermore, this attenuated threat extinction during adolescence is associated with an altered synaptic plasticity in the infralimbic medial prefrontal cortex (IL-mPFC), a brain region critical for threat extinction. However, the mechanism underlying the altered plasticity in the IL-mPFC during adolescence is unclear. Given the purported role of vasoactive intestinal polypeptide expressing interneurons (VIPINs) in disinhibition and hence their potential to affect cortical plasticity, we examined whether VIPINs exhibit an adolescence-specific plasticity in the IL-mPFC. We observed an increase in GABAergic transmission and a decrease in excitability in VIPINs during adolescence. Male mice show a significantly higher VIPIN-pyramidal neuron GABAergic transmission compared with female mice. The observed increase in GABAergic transmission and a decrease in membrane excitability in VIPINs during adolescence could play a role in the altered plasticity in the adolescent IL-mPFC. Furthermore, the suppression of VIPIN-mediated GABAergic transmission in females might be relevant to sex differences in anxiety disorders.

China's economy will struggle to halt secular slowdown

2021 ◽  
Keyword(s):  
High Speed ◽  
Regression To The Mean ◽  
Content Type ◽  
Strong Force ◽  
Global Demand ◽  
The Mean ◽  
Productivity Gains ◽  
Global Growth ◽  
China’S Economy

Significance Comparisons with two formerly fast-growing Asian neighbours, Japan and South Korea, suggest that China will continue to slow for another decade. Analysis of global growth trends over 50 years points to a strong force of ‘regression to the mean’, meaning that continued high-speed growth is statistically unlikely. Impacts Continued Chinese economic slowing will reduce global demand for resources such as iron ore and coal. Achieving productivity growth will require deepening reforms to increase the role of the market, the private sector and competition. World Bank economists emphasise that imposing stricter financial discipline is a key step to enhancing market-based productivity gains.

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