Search results for "Smooth Muscle"
showing 6 items of 156 documents
Potential role of the neuropeptide CGRP in the induction of differentiation of rat hepatic portal vein wall.
2005
The media of the rat hepatic portal vein is composed of an internal circular muscular layer (CL) and an external longitudinal muscular layer (LL). These two perpendicular layers differentiate progressively from mesenchymal cells within the first month after birth. In this paper, we studied the development of calcitonin gene-related peptide (CGRP) innervation during post-natal differentiation of the vessel. We show that CGRP innervation is already present around the vessel at birth in the future adventitia but far from the lumen of the vessel. Progressively, CGRP immunoreactive fibers reached first LL then CL. CL by itself become only innervated at day 14 after birth. This corresponds to the…
Insulin resistance aggravates atherosclerosis by reducing vascular smooth muscle cell survival and increasing CX3CL1/CX3CR1 axis.
2014
Aims Insulin resistance (IR) is a major risk factor for cardiovascular disease and atherosclerosis. Life-threatening acute events are mainly due to rupture of unstable plaques, and the role of vascular smooth muscle cells (VSMCs) in this process in IR, Type 2 diabetes mellitus, and metabolic syndrome (T2DM/MetS) has not been fully addressed. Therefore, the role of VSMC survival in the generation of unstable plaques in T2DM/MetS and the involvement of inflammatory mediators was investigated. Methods and results Defective insulin receptor substrate 2 (IRS2)-mediated signalling produced insulin-resistant VSMCs with reduced survival, migration, and higher apoptosis than control cells. Silencing…
Vascular effects of progesterone: Role of cellular calcium regulation
2001
Abstract —Vascular actions of progesterone have been reported, independently of estrogen, affecting both blood pressure and other aspects of the cardiovascular system. To study possible mechanisms underlying these effects, we examined the effects of P in vivo in intact rats and in vitro in isolated artery and vascular smooth muscle cell preparations. In anesthetized Sprague-Dawley rats , bolus intravenous injections of P (100 μg/kg) significantly decreased pressor responses to norepinephrine (0.3 μg/kg). In vitro, progesterone (10 −8 to 10 −5 mmol/L) produced a significant, dose-dependent relaxation of isolated helical strips, both of rat tail artery precontracted with KCl (60 mmol/L) or a…
Localization of Bradykinin B2Receptors in the Endometrium and Myometrium of Rat Uterus and the Effects of Estrogen and Progesterone1
1999
In the uterus, bradykinin is a potent inducer of smooth muscle contraction, which is mediated by the bradykinin B2 receptor subtype. However, little is known about the distribution or regulation of this receptor in this tissue. The aim of this study was to localize the B2 receptor in the uterus and determine whether the levels of this receptor were altered during the estrous cycle and modulated by estrogen and/or progesterone in ovariectomized rats. At diestrus, uterine B2 receptors were localized to both the circular and longitudinal smooth muscle layers of the myometrium, the endometrial stroma, the glandular epithelium, and the layer subjacent to the luminal epithelium. B2 receptor level…
Duodenal contractile activity in dystrophic (mdx) mice: reduction of nitric oxide influence.
2003
The present study was undertaken to analyse duodenal contractility in adult dystrophic (mdx) mice. The spontaneous changes of the isometric tension and the responses of longitudinal duodenal muscle to nonadrenergic, noncholinergic (NANC) nerve stimulation and to exogenous drugs were compared between normal and mdx mice. Duodenal segments from mdx mice displayed spontaneous contractions with higher frequency than normals. N omega-nitro-L-arginine methyl ester (L-NAME) increased the frequency of contractions in normals without affecting that in mdx mice. In normals, NANC nerve stimulation elicited a transient relaxation abolished by L-NAME. In mdx mice a frank relaxation was not observed, the…
Leiomyoma of the hard palate : a case report
2007
Leiomyoma is a benign smooth muscle tumor that is very rarely located in the oral cavity. It is accepted that the smooth muscle giving rise to this tumor corresponds to the tunica media of the arteries. The tumor can develop at any age, with no clear gender predilection, and typically manifests as a slow-growing, asymptomatic lesion. The diagnosis is based on the histopathological study, with the use of specific staining techniques, including immunohistochemical markers. Treatment consists of complete resection of the lesion, with due safety margins. We present the case of a 57-year-old male with a tumor located for the previous four months in the region of the hard palate, adjacent to the …