ISSN:0001-6772    

DOI:10.1111/j.1748-1716.1989.tb08543.x

出版商:Blackwell Publishing Ltd    

年代:1989

数据来源: WILEY

摘要:

By means of two‐colour immunocytochemistry using a mouse monoclonal antibody directed against the rat liver glucocorticoid receptor (GR) and a rabbit polyclonal neuropeptide Y (NPY) antiserum combined with the biotin‐avidin immunoperoxidase and a double immunofluorescence procedure, it has been possible to demonstrate nuclear GR immunoreactivity (IR) in neurons showing cytoplasmatic NPY IR in rat brain. The majority of NPY immunoreactive perikarya of the medial parvocellular part of the arcuate nucleus, locus coeruleus and the rostral and caudal part of the ventrolateral medulla oblongata contained strong nuclear GR IR. Many of the NPY immunoreactive neurons present in the subnuclei of the nucleus tractus solitarius also contained nuclear GR IR, while most of the NPY immunoreactive perikarya of the cerebral cortex and all of the neostriatum appeared to lack GR IR. These results indicate that NPY immunoreactive neurons in the upper and lower brain stem, but not in the cerebral cortex and in the neostriatum may be directly involved in mediating central effects of glucocortico

ISSN:0001-6772    

DOI:10.1111/j.1748-1716.1989.tb08544.x

出版商:Blackwell Publishing Ltd    

年代:1989

数据来源: WILEY

摘要:

The objective was to study whether the high erythropoietic stimulatory activity found in plasma from neonatal mice during the growth period is erythropoietin (Ep) alone, or Ep in combination with other factors. Plasma from hypertransfused neonatal (20 d) and adult (13–20 weeks) mice were compared with a radioimmunoassay (RIA) and a cell culture assay for Ep. The RIA determines immunoreactive Ep (iEp) while the cell culture assay reflects erythropoiesis stimulating factor(s) (ESF). Compared to control values, hypertransfusion resulting in PCVs of 55% and higher reduced the mean iEp levels in neonatal and adult mice by 82% and 38%, respectively (P0.3). The parallel ESF data showed a reduction in mean plasma ESF levels by 68% in hypertransfused neonatal and 72% in hypertransfused adult animals (P<0.001). And notably, in contrast to the iEp data, the mean ESF level found in hypertransfused neonatal mice with PCVs of 55% and higher was significantly above that of hypertransfused adult animals (P<0.001). No correlation was found between PCV and iEp (r0.1) or ESF (r0.2) in hypertransfused animals. The parallel data from the two Ep assays show that plasma from hypertransfused 20‐d‐old mice contain one or more erythropoietic stimulatory factors not detected by the RIA. It is concluded that part of the high erythropoietic stimulatory activity found in plasma from neonatal mice is due to non‐Ep

ISSN:0001-6772    

DOI:10.1111/j.1748-1716.1989.tb08545.x

出版商:Blackwell Publishing Ltd    

年代:1989

数据来源: WILEY

摘要:

The overflows of noradrenaline (NA) and neuropeptide Y like immunoreactivity (NPYLI) and vascular responses upon sympathetic nerve stimulation were analysed in the nasal mucosa of pentobarbital anaesthetized pigs. In controls, a frequency‐dependent increase in NA overflow was observed whereas detectable release of NPY‐LI occurred only at 6.9 Hz. Parallel decreases in blood flow in the sphenopalatine artery and vein and in nasal mucosa volume (reflecting blood volume in the venous sinusoids) were observed. The laser Doppler flowmeter signal (reflecting superficial blood flow) increased upon low and decreased upon high frequency stimulation. Twenty‐four hours after reserpine pretreatment and preganglionic decentralization, the NA overflow was abolished while a frequency‐dependent release of NPY‐LI occurred. Forty, 60 and 80% of the vasoconstrictor responses then remained upon stimulation with a single impulse, 0.59 and 6.9 Hz, respectively. Both the vasoconstriction and NPY‐LI overflow, however, were subjected to fatigue upon repeated stimulation. In reserpinized animals release of NPY‐LI and vasoconstrictor responses were larger upon stimulation with irregular bursts at 0.59 Hz compared to effects seen at stimulation with continuous impulses. Pre‐treatment with the a‐adrenoceptor antagonist phenoxybenzamine or the monoamine reuptake inhibitor, desipramine, enhanced NA overflow by 2–3 and 1.5 times at 0.59 and 6.9 Hz, respectively. Phenoxybenzamine significantly reduced the nerve‐evoked vascular responses while the release of NPY‐LI at 6.9 Hz was increased. Desipramine increased the functional responses but reduced the NPY‐LI overflow. During tachyphylaxis to the vasoconstrictor effects of the stable adenosine 5′‐triphosphate (ATP) analogue α‐β‐methylene ATP (mATP) in controls, the vasoconstrictor responses as well as the NA and NPY‐LI overflow to nerve stimulation were unmodified. In reserpinized animals, however, the vascular responses and the overflow of NPY‐LI were reduced after mATP tachyphylaxis.These data show that both NA and NPY are released upon sympathetic nerve stimulation in the nasal mucosain vivoand this release seems to be regulated via prejunctional a‐adrenoceptors. The lack of effect of mATP tachyphylaxis under control conditions makes it less likely that ATP serves as a major mediator of the larg

ISSN:0001-6772    

DOI:10.1111/j.1748-1716.1989.tb08546.x

出版商:Blackwell Publishing Ltd    

年代:1989

数据来源: WILEY

摘要:

A newin vivomodel is described in which anaesthetized pigs were used to study vascular responses in the bronchial, upper tracheal and laryngeal circulation upon electrical stimulation of the vagal or superior laryngeal nerves. Vagal or superior laryngeal nerve stimulation increased blood flow in the bronchial artery and the superior laryngeal artery, respectively. After pre‐treatment with atropine the vasodilatory response in the bronchial artery upon stimulation was not modified while the increase in blood flow in the superior laryngeal artery was reduced. The ganglionic blocking agent chlorisondamine further reduced the nerve stimulation evoked decrease in vascular resistance in the superior laryngeal artery, but did not influence the response of the bronchial artery. Capsaicin induced a marked increase in blood flow both in the bronchial and superior laryngeal arteries after pre‐treatment with atropine, guanethidine and chlorisondamine. After capsaicin tachyphylaxis, the vasodilatation upon nerve stimulation in the bronchial artery and the smaller remaining decrease in vascular resistance in the superior laryngeal artery were strongly reduced. Thus, antidromic stimulation of afferent C fibres may increase blood flow via release of vasodilatory peptides such as tachykinins and calcitonin gene‐related peptide.The present findings show that local blood flow in the larynx and upper trachea is regulated by cholinergic and non‐cholinergic parasympathetic mechanisms and a small capsaicin sensitive, sensory component. On the other hand, the vagal control of the bronchial circulation seems to exclusively involve capsaicin sensitive sensory

ISSN:0001-6772    

DOI:10.1111/j.1748-1716.1989.tb08547.x

出版商:Blackwell Publishing Ltd    

年代:1989

数据来源: WILEY

摘要:

Coronary flow regulation in man is incompletely understood. We addressed the hypothesis that endogenous adenosine and prostacyclin (PGI2) affect basal coronary tone and/or the coronary flow response to increased myocardial work. In healthy volunteers coronary sinus flow and cardiac oxygen extraction were measured at rest and during leg exercise (40–50 W), before and after i. v. administration of theophylline (to block adenosine receptors) and oral administration of ibuprofen (to inhibit prostaglandin synthesis). Before drug, the basal coronary flow was 118 ± 23 ml min‐1and the cardiac extraction of oxygen 122 ± 3 ml 1‐1. Leg exercise elevated coronary flow by 89 ± 16 ml min′. Theophylline, at a dose blocking the coronary flow response to dipyridamole (an adenosine‐dependent mechanism), induced a moderate increase in myocardial oxygen extraction (by 11%,P<0.05), but failed to affect either the basal coronary flow (105 ± 16 ml min‐1) or the increase during exercise (88 ± 25 ml min‐1). Ibuprofen inhibited the urinary excretion of PGI2metabolite by about 90%, but did not affect basal coronary tone or the coronary response to exercise. These data indicate that endogenous adenosine is of limited importance for normal coronary regulation in man, and that

ISSN:0001-6772    

DOI:10.1111/j.1748-1716.1989.tb08548.x

出版商:Blackwell Publishing Ltd    

年代:1989

数据来源: WILEY

摘要:

Spontaneously hypertensive rats (SHR) and stroke‐prone spontaneously hypertensive rats (SHRSP) were treated with a combination of a beta1‐blocker (metoprolol) and a calcium antagonist (felodipine) from 1 to 4 or from 4 to 6‐months of age. The main trunk and peripheral branches of the mesenteric arterial tree were fixed by immersion and embedded in plastic. The total length of the internal elastic membrane and the media area were measured in cross‐sectioned arteries. The ratio between media thickness (m) and lumina radius (ri) was then determined for a calculated, standardized condition, assuming a smooth and circular internal elastic membrane. The treatment caused a significant decrease in blood pressure and a reduction in m/riratios in the mesenteric arterial trunk as well as in mesenteric arterial branches when initiated in young as well as in adult SHR and SHRSP, i. e. the therapy efficiently prevents as well as reverses hypertensive arterial changes. The m/riratios in the superior mesenteric arterial trunks were significantly smaller in treated 4‐month‐old SHR and SHRSP than in WKY, although their blood pressures were not fully normalized. There was a marked increase in luminal radius in the young treated rats, possibly secondary to a therapy‐induced increase in splanchn

ISSN:0001-6772    

DOI:10.1111/j.1748-1716.1989.tb08549.x

出版商:Blackwell Publishing Ltd    

年代:1989

数据来源: WILEY

摘要:

The influence of the parasympathetic pelvic nerves on anorectal motility was studied in anaesthetized cats. Anal pressure and rectal motility were recorded by a manometric and a volumetric method, respectively. Severing of the pelvic nerves did not cause any pressure change in the anus, indicating that these nerves are not significantly tonically active. Efferent low intensity (0.05–0.5 ms, 8 V at 5 Hz) electrical stimulation of the pelvic nerves (PNS) elicited a contraction of the internal anal sphincter (IAS), while high intensity stimulation (>1 ms, 8 V at 5 Hz) caused a sphincter relaxation. A rectal contraction was noted on both low and high intensity stimulation. After sectioning of the sympathetic nerves, PNS elicited a contraction in both the anus and the rectum irrespective of stimulation intensity. PNS inhibited the anal contraction elicited by simultaneous stimulation of the sympathetic nerves or noradrenaline infusion. The inhibitory anal responses to PNS were unaffected or augmented by atropine, unaffected by propranolol and abolished by hexamethonium. The excitatory anal effects of PNS were reduced or abolished by atropine and abolished by phentolamine. The rectal contraction induced by low intensity PNS was abolished by atropine or converted to a relaxation. In half of the experiments an atropine resistant rectal contraction was observed in response to high intensity PNS.The results are consistent with a pelvic nerve influence on IAS pressure through several mechanisms, including modulation of the activity in the sympathetic nerves and activation of inhibitory non‐adrenergic, non‐cholinergic neurons. The pelvic nerves convey both cholinergic and non‐cholinergic excitatory, as well as non‐adrenergic, noncholinergic inhibitory fibres to t

ISSN:0001-6772    

DOI:10.1111/j.1748-1716.1989.tb08550.x

出版商:Blackwell Publishing Ltd    

年代:1989

数据来源: WILEY

ISSN:0001-6772    

DOI:10.1111/j.1748-1716.1989.tb08551.x

出版商:Blackwell Publishing Ltd    

年代:1989

数据来源: WILEY

ISSN:0001-6772    

DOI:10.1111/j.1748-1716.1989.tb08552.x

出版商:Blackwell Publishing Ltd    

年代:1989

数据来源: WILEY