摘要:

The perivascular autonomic nerves of the major blood vessels on the ventral surface of the brain were studied in the streptozotocin-induced diabetic rat, an animal model for juvenile onset of diabetes. Histochemical and immunohistochemical techniques were used to determine the pattern and density of perivascular nerves containing catecholamine, 5-hydroxytryptamine (5-HT), vasoactive intestinal polypeptide (VIP) and neuropeptide Y (NPY). A significant reduction in the density and/or fluorescence intensity of 5-HT-immunoreactive nerves was observed in the circle of Willis and its main arterial branches namely: basilar, superior cerebellar, internal carotid, posterior communicating, middle cerebral and anterior cerebral arteries, while a significant reduction of VIP-immunoreactive nerves was observed in the internal carotid, middle cerebral and anterior cerebral arteries, but not in the basilar, superior cerebellar and posterior communicating arteries 8 weeks after the onset of diabetes. However, no changes were observed in the density of NPY- and catecholamine-containing nerves. The results are discussed in relation to autonomic neuropathy of the cerebral blood vessels in diabetes.

ISSN:1018-1172    

DOI:10.1159/000158693

出版商:S. Karger AG    

年代:1987

数据来源: Karger

摘要:

The purpose of this study was to provide anatomical information about innervation density and the neuromuscular relationship in the rabbit central ear artery and its main side branch, so that, when combined with functional observations, a better understanding of neuroeffector mechanisms in these vessels could be established. Electron-microscopic methods were used to measure number and size of axon varicosities, their content of vesicles, the sizes of dense cores in the small vesicles and the neuromuscular cleft width. For each 100 µm of the outer circumference of the tunica media, the central ear artery contained 4 varicosities with a total cross-sectional area of 2.2 µm2, and the main side branch about 9 varicosities with a total cross-sectional area of 4.1 µm2. On the average, the varicosities of the central and branch arteries contained 93.6 and 95.1 small, and 2.3 and 1.9 large vesicles, respectively, per micron. The diameter of dense cores in the small vesicles was significantly smaller in the main side branch (18.3 vs. 16.7 nm). In the central ear artery, the mean cleft width was 5.27 µm, and 3% of all clefts were narrower than 1 µm. In the main side branch, the mean cleft width was 2.77 µm, and 22% were narrower than 1 µm. Thus, the innervation of the main side branch is closer to the vascular smooth muscle cells and is characterized by a larger number of smaller varicosities per unit circumference. Although vesicle density is the same as in the central artery, the dense cores are smaller in diameter. These data do not provide an explanation as to why the response of the main side branch to nerve stimulation in vitro is proportionally weaker. The reasons for this apparent contradiction are not clear, but we offer some possible explan

ISSN:1018-1172    

DOI:10.1159/000158694

出版商:S. Karger AG    

年代:1987

数据来源: Karger

摘要:

The release of endothelium-derived relaxing factor (EDRF) was examined in the rabbit carotid artery 6 weeks after denudation with an inflated balloon catheter in vivo. A concentric, fibromuscular intimal thickening of variable width developed in all areas lined with either regenerated endothelium or modified luminal smooth muscle cells. In vitro studies showed that in vessels precontracted with serotonin, only the re-endothelialized areas could relax to the endothelium-dependent dilators methacholine, substance P and the Ca2+ ionophore A23187. Re-endothelialized areas with large concentric, fibromuscular intimal thickening (between 10 and 20 cells thick) relaxed with a similar sensitivity and maximum to methacholine compared with control areas. It is concluded that (1) newly generated endothelial cells release EDRF whilst the specialized lining smooth muscle cells present 6 weeks after injury do not, and (2) that the presence of a large fibromuscular intima does not prevent EDRF from reaching the media to cause relaxation.

ISSN:1018-1172    

DOI:10.1159/000158695

出版商:S. Karger AG    

年代:1987

数据来源: Karger

ISSN:1018-1172    

DOI:10.1159/000158696

出版商:S. Karger AG    

年代:1987

数据来源: Karger