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T Elsås

Publications and source records attributed to T Elsås.

At least 19 recordsLinked to original sources
PubMed2001

Origin and Co-localization of nitric oxide synthase, CGRP, PACAP, and VIP in the cerebral circulation of the rat.

The origin of perivascular nerve fibres storing nitric oxide synthase (NOS) and co-localisation with perivascular neuropeptides were examined in the rat middle cerebral artery (MCA) by retrograde tracing with True Blue (TB) in combination with immunocytochemistry. Application of TB to the proximal part of the middle cerebral artery labelled nerve cell bodies ipsilaterally in the trigeminal, sphenopalatine, otic, and superior cervical ganglia. A few labelled cell bodies were seen contralaterally, suggesting bilateral innervation. In the parasympathetic sphenopalatine and otic ganglia, numerous TB-labelled cell bodies contained neuronal NOS (C- and N-terminal), vasoactive intestinal peptide (VIP), and pituitary adenylate cyclase activating peptide (PACAP). In the trigeminal ganglion, almost all TB-labelled cell bodies contained calcitonin gene-related peptide (CGRP) but only a few cells contained NOS. In the superior cervical ganglion, the majority of the TB-labelled nerve cells contained neuropeptide Y (NPY) but none of them contained NOS. Removal of the ipsilateral sphenopalatine ganglion caused a slight reduction in the number of perivascular VIP-, PACAP-, and NOS-containing fibres after 3 days in the MCA while there was no difference at 2 and 4 weeks after the denervation as compared to control. This indicates that the parasympathetic VIP-, PACAP-, and NOS-immunoreactive nerve fibres in the rat MCA originate from several sources.

Animals↗
PubMed1997

Evidence for a possible synergism between pituitary adenylate cyclase activating polypeptide and calcitonin gene-related peptide in porcine ophthalmic artery.

The activities of pituitary adenylate cyclase activating polypeptide (PACAP) and calcitonin gene-related peptide (CGRP) were investigated in isolated segments of porcine ophthalmic artery. In artery segments pre-contracted by prostaglandin F2alpha, PACAP induced a concentration dependent relaxation, but was clearly less potent than CGRP. When 2 x 10(-10) M CGRP (relaxation 4.3 +/- 0.8%, n = 11) and 10(-8) M PACAP (relaxation 12.4 +/- 3.8%, n = 10) were added together, the subsequent relaxation was substantially increased (33.6 +/- 5.6%, p<0.0005). In addition, the rate of relaxation was increased. The results indicate that there is synergism between low concentrations of CGRP and PACAP in isolated porcine ophthalmic artery.

Animals↗
PubMed1996

Pituitary adenylate cyclase-activating peptide-immunoreactive nerve fibers in the cat eye.

PURPOSE: To study the occurrence and distribution of the neuropeptide pituitary adenylate cyclase-activating peptide (PACAP) in ocular and orbital structures of the cat. METHODS: Immunocyto-chemistry to localize PACAP and double immunostaining to detect co-localization of PACAP with other neuropeptides. RESULTS: Numerous PACAP-immunoreactive nerve fibers were observed in the lacrimal gland, choroid and retroocular arteries. There was a sparse supply of PACAP-containing nerve fibers in the iris, ciliary body and conjunctiva. Subpopulations of PACAP-containing nerve fibers stored vasoactive intestinal peptide (VIP) or calcitonin gene-related peptide (CGRP). Around 10% of the ganglion cells in the sphenopalatine ganglion harbored PACAP immunoreactivity. In the trigeminal ganglion around 5% of the neuronal cell bodies and in the ciliary ganglion only occasional ganglion cells contained PACAP immunoreactivity. PACAP immunoreactivity co-localized with VIP in the sphenopalatine ganglion and with CGRP in the trigeminal ganglion. CONCLUSION: PACAP-containing nerves in the eye and associated structures demonstrate a distribution pattern resembling that of VIP. Subpopulations of nerve fibers containing PACAP immunoreactivity store VIP or CGRP immunoreactivity. Neuronal PACAP in the eye and orbit may take part in regulation of smooth muscle tone, glandular secretion and sensory processing.

Animals↗
PubMed1996

Vasoactive intestinal peptide- and nitric oxide synthase-containing nerve fibers in the rat ophthalmic artery have different origins.

BACKGROUND: Neuropeptides are important in the regulation of vascular functions. The purpose of the present study was to investigate the distribution of perivascular nerve fibers containing neuropeptides and nitric oxide synthase (NOS) in the rat ophthalmic artery. METHODS: Neuropeptide- and NOS-containing nerve fibers in the rat ophthalmic artery were identified using immunocytochemistry following unilateral parasympathectomy (electrocoagulation of the sphenopalatine ganglion) and sympathectomy (superior cervical ganglionectomy). The contralateral artery was used as control. RESULTS: Nerve fibers containing vasoactive intestinal peptide (VIP), neuropeptide Y (NPY) and NOS were abundant in the wall of the ophthalmic artery. Nerve fibers containing calcitonin gene-related peptide and substance P were scarcer. Following destruction of the sphenopalatine ganglion there was no discernible change in the density of VIP- and NPY-immunoreactive fibers, while the majority of the NOS-containing fibers disappeared. Following sympathectomy the NPY-containing nerve fibers were almost completely eliminated, whereas VIP- and NOS-containing fibers were unaffected. CONCLUSION: The present study demonstrates that the sphenopalatine ganglion is the main contributor of NOS-containing nerve fibers to the rat ophthalmic artery. In contrast, this ganglion apparently is of little importance as a source of VIP-immunoreactive nerve fibers to the artery, demonstrating different origins of the majority of the VIP-and NOS-containing fibers to this artery. The NPY-containing nerve fibers in the rat ophthalmic artery emanate mainly from the superior cervical ganglion.

Animals↗
PubMed1996

Vasoactivity mediated by endothelin ETA and ETB receptors in isolated porcine ophthalmic artery.

Endothelin isopeptides and sarafotoxin S6b induced strong contractions in isolated porcine ophthalmic artery at basal tension, which were antagonized in a concentration-dependent manner by the specific ETA antagonist FR 139317. The maximum contraction and potency of endothelin-1 and sarafotoxin S6b were similar, whereas endothelin-3 was significantly less potent and induced weaker contractions. Schild plot analysis was only obtained for endothelin-1 and sarafotoxin S6b, but indicated competitive binding at the same ETA receptor site for these peptides. However, the slope obtained for endothelin-1 was significantly less than unity, suggesting more than one receptor. FR 139317 was a more potent antagonist of contractions induced by endothelin-3 than the other peptides. In arteries pre-contracted by prostaglandin F2 alpha high endothelin-3 concentrations induced additional contraction, except in the presence of FR 139317 when a marked relaxation was observed, an ability which was otherwise marked by the strong contractile activity. The relaxation was significantly reduced in endothelin-denuded segments. Both contraction and relaxation were abolished by the ETA/B antagonist bosentan. The results suggest the presence of ETB as well as ETA receptors in this artery type, though ETB receptor activity is only demonstrated at an unusually high concentration of endothelin in this preparation in vitro.

Animals↗
PubMed1995

Pituitary adenylate cyclase activating polypeptide is expressed in autonomic neurons.

Pituitary adenylate cyclase activating polypeptide (PACAP) is a novel vasoactive intestinal peptide (VIP)-like peptide, which is present in neuronal elements of several peripheral organs, and thus a putative neurotransmitter/modulator. In the present study, the expression of PACAP in two parasympathetic ganglia (otic, sphenopalatine) and one mixed parasympathetic/sensory ganglion (jugular-nodose) in rat was characterized by use of in situ hybridization and immunocytochemistry and compared to that of VIP and calcitonin gene-related peptide (CGRP). PACAP and VIP were expressed in virtually all nerve cell bodies in the otic and sphenopalatine ganglia; PACAP and VIP were also expressed in subpopulations of nerve cell bodies in the jugular-nodose ganglion. CGRP was expressed in numerous nerve cell bodies in the jugular-nodose ganglion and in a few, scattered, nerve cell bodies in the sphenopalatine ganglion. In the otic and sphenopalatine ganglia, PACAP- and VIP-like immunoreactivities were frequently co-localized; in the jugular-nodose ganglion, PACAP-like immunoreactivity was frequently co-localized with CGRP-like immunoreactivity in presumably sensory neurons and to a lesser extent with VIP in parasympathetic neurons. Thus, PACAP is synthesized and stored in autonomic parasympathetic neurons as well as in vagal sensory neurons, which provides an anatomical basis for the diverse effects of PACAP previously described.

Animals↗
PubMed1995

Neuropeptide Y (NPY) in the orbital arteries of the rabbit. Immunocytochemistry and vasomotor activity.

The purpose of the present study was to investigate the presence and vascular effects of neuropeptide Y in the rabbit orbital arteries. Neuropeptide Y-containing nerve fibers were demonstrated, using an indirect immunofluorescence method with a neuropeptide Y antiserum raised in goat against porcine neuropeptide Y. Isometric responses in isolated circular segments of the orbital arteries were measured following application of neuropeptide Y, different contracting agonists, and the neuropeptide Y blocker alpha-trinositol. A rich supply of neuropeptide Y-containing nerve fibers was seen around the orbital arteries. Neuropeptide Y (10(-10)-10(-6) M) did not induce any contractions in resting arterial segments. Noradrenaline and histamine evoked concentration dependent constrictions which were potentiated by neuropeptide Y (3 x 10(-7) M). This potentiation was completely blocked by alpha-trinositol (3 x 10(7) M). The contractile effects of endothelin-1, endothelin-3, prostaglandin F2 alpha, and 5-hydroxytryptamine were not modified by neuropeptide Y.

Animals↗
PubMed1994

Neuronal pathways to the rat conjunctiva revealed by retrograde tracing and immunocytochemistry.

The origin and neuropeptide content of nerve fibres in the rat conjunctiva were studied by retrograde tracing and denervations in combination with immunocytochemistry. Immunocytochemistry revealed nerve fibres containing neuropeptide Y (NPY), vasoactive intestinal peptide (VIP), peptide histidine isoleucine (PHI), helospectin, substance P (SP), and calcitonin gene-related peptide (CGRP) around blood vessels, smooth muscle bundles and glands. Removal of the sphenopalatine ganglion eliminated the majority of the VIP-, PHI- and helospectin-containing fibres. Sympathectomy eliminated the majority of the NPY-containing fibres in the conjunctiva. Removal of both the sphenopalatine ganglion and the superior cervical ganglion led to further reduction of the NPY fibres. Injection of the retrograde tracer True Blue into the conjunctiva resulted in the appearance of labelled cell bodies in the trigeminal ganglion, the sphenopalatine ganglion, the superior cervical ganglion, and the ciliary ganglion. Judging from the number of labelled nerve cell bodies, the superior cervical ganglion contributes most to the innervation. These results indicate that the majority of NPY-containing nerve fibres in the conjunctiva derives from the superior cervical ganglion (sympathetic nerve supply). Most of the VIP- and a minor population of the NPY-containing fibres in the conjunctiva originate in the sphenopalatine ganglion (parasympathetic nerve supply). A sparse amount of VIP- and NPY-containing fibres derives from the ciliary ganglion. Nerve fibres containing SP and/or CGRP emanate from the trigeminal ganglia (sensory nerve supply). Together the findings indicate that several ganglia project to the conjunctiva and that many neuropeptides may be involved in the control of conjunctival activity.

Animals↗
PubMed1994

Pressure increase following primary laser trabeculoplasty. Effect on the visual field.

Possible damaging effects on the visual field of postlaser pressure elevations the first 24 h following primary laser trabeculoplasty were investigated in 61 patients with exfoliative or open-angle glaucoma. The intraocular pressure was monitored the first 24 h after treatment. Treatment with pressure reducing agents was started if the intraocular pressure was > or = 50 mmHg. The visual field was plotted before and 1, 3, and 6 months after laser treatment with the C-30-2 program on a Humphrey visual field analyzer. Peak pressures > or = 50 mmHg occurred with 15 (25%) patients. There was no relationship between visual field changes at 1 month and pressure increase, peak pressure, prelaser pressure, prelaser visual field indices, the use of timolol postlaser, or the pressure decrease or pressure level 1 month after laser treatment. From 1 to 6 months after laser trabeculoplasty the visual field parameters remained stable. Postlaser pressure spikes do not seem to damage the visual field providing they are detected and treated.

Aged↗
PubMed1993

Cluster headache in identical twins.

Twin brothers with cluster headache are described. Monozygosity was demonstrated by conventional genetic markers and DNA-typing. Both had "mini-bouts" in the early stages. In the one, attacks were always excruciatingly severe; in the other, they started out as "mild", eventually becoming more severe. Both brothers also suffered from paroxysmal tachycardia. The connection between attacks of tachycardia and cluster headache remains enigmatic. The observation of cluster headache in monozygotic twins underscores the importance of genetic factors in the etiology. The ratio between cluster headache prevalence in close family members vs. prevalence in the general population may be higher in cluster headache than in migraine.

Cluster Headache↗
PubMed1993

The middle-Norway eye-screening study. III. The prevalence of capsular glaucoma is influenced by blood-group antigens.

The association between blood groups (ABO, Rh, Kell, Duffy) and pseudo-exfoliation syndrome, simple, and capsular glaucoma have been evaluated. The findings were: 1). No statistically significant abnormalities regarding blood group distribution in persons with pseudo-exfoliation syndrome. 2). In contrast to simple glaucoma, capsular glaucoma showed an abnormal distribution in the ABO- and the Kell-system. There was less glaucoma prevalence in the capsular A1-group compared to the O-group (p = 0.013), and less in the K1 negative group compared to the K1 positive one (p = 0.005). This trend was even escalated when combining the two systems: Among the K1 negative persons the glaucoma prevalence was lower in the A1-group compared to the O-group (p = 0.003). In the K1 negative group only 9 of 61 A1-persons developed glaucoma, in contrast to the K1 positive group where 4 of 4 A1-persons had glaucoma. This difference gave p < or = 0.00038, whereas the corresponding difference for the O-groups showed p = 0.65. It is concluded that once a person with blood group A1 has developed pseudo-exfoliation syndrome, the risk that capsular glaucoma will occur is about 7 times higher when that person is K1 positive compared to K1 negative. Perhaps this observation may be used as a prognostic factor for non-glaucomatous PE positive persons.

Aged↗
PubMed1992

Substance P augments the rate of vasodilation induced by calcitonin gene-related peptide in porcine ophthalmic artery in vitro.

Peptides may function as neurotransmitters liberated antidromically by sensory nerve fibres, provoking vascular responses having potential importance in some neurological disorders. Dose-response relaxation curves induced by substance P (SP) and calcitonin gene related peptide (CGRP) have been studied in porcine ophthalmic arteries in vitro. Both peptides induced vasodilation when tested separately (CGRP much greater than SP). Because of the putative interactions between such peptides in this vascular territory, a computerised system was also used for analysing over time the response to a single addition of either 10(-8) M CGRP, 10(-8) M SP or a combination of 10(-8) M SP + 10(-8) M CGRP. SP did not augment the maximum relaxation induced by CGRP alone, but increased significantly the rate of relaxation during the initial phase of the response. The effect induced by the SP+CGRP combination was stronger than the sum of the individual SP and CGRP-induced relaxations during the first 4 min of the response, which suggests a SP-CGRP synergism in this artery.

Animals↗
PubMed1992

SUNCT syndrome: VII. Ocular and related variables.

SUNCT is a unilateral headache syndrome with shortlasting attacks, accompanied by e.g. conjunctival injection and lacrimation on the painful side. Intraocular pressure (IOP), corneal indentation pulse (CIP) amplitudes, episcleral venous pressure, and corneal, tympanic, and facial temperature have been studied in 6 SUNCT patients. IOP and CIP amplitudes increased on the painful side during headache paroxysms, while episcleral venous pressure remained unchanged. Corneal temperature seemed to increase during attack on both sides. However, the number of observations during attacks is scanty. Outside of attacks, the corneal temperature on the symptomatic side seemed to be higher when compared with the non-symptomatic side (generally > or = 0.5 degrees C), provided that the attack frequency was high. The facial temperature seemed to be even on both sides or slightly higher on the symptomatic than on the non-symptomatic side in the periocular area. This pattern seems to be different from the one in trigeminal neuralgia, in which the temperature has been reported to be lowest on the painful side of the face. During attacks, there seemed to be a tendency for the temperature to increase in the periocular area, but not over the mandible or in the neck. The results obtained could be caused by increased blood supply to the eye (and the surrounding skin) on the symptomatic side because of vasodilatation during repeated pain attacks. As far as the ocular changes are concerned, probably the arteriolar side of the vascular bed is involved.

Aged↗
PubMed1991

Diurnal intraocular pressure after successful primary laser trabeculoplasty.

In 20 patients who were successfully treated with laser trabeculoplasty as the primary therapy for glaucoma, we measured the intraocular pressure every two hours between 8:00 A.M. and 8:00 P.M. Success was defined as intraocular pressure of 22 mm Hg or less without medication. Of 20 patients, three had open-angle glaucoma and 17 had exfoliative glaucoma. Intraocular pressure was stable with small fluctuations during the daytime.

Aged↗
PubMed1991

Pilocarpine to prevent acute pressure increase following primary laser trabeculoplasty.

The effect of pilocarpine pretreatment on the transient pressure elevations immediately following primary laser trabeculoplasty was investigated in a prospective, randomised study. Fifty eyes of 50 patients, 33 with exfoliative and 17 with simple glaucoma, were treated in 360 degrees of the trabecular meshwork. The mean maximum pressure increase was 2.4 (SD = 4.4)mm Hg with pilocarpine pretreatment and 12.8 (SD = 11.2)mm Hg without pretreatment (p less than 0.05). Except in two cases, all peak pressures appeared during the first two hours after treatment. The degree of chamber angle pigmentation was predictive of the magnitude of the post laser hypertensive pressure response in eyes without pretreatment (p less than 0.05).

Aged↗
PubMed1991

The middle-Norway eye-screening study. II. Prevalence of simple and capsular glaucoma.

In this population-based screening study, dealing with 1941 persons above 64 years of age from three different municipalities, the overall open-angle glaucoma prevalence was found to be 8.3%. The prevalence in the separate areas (7.0%, 8.6%, and 9.5%) were not statistically different. Roughly 30% of the population with pseudo-exfoliation syndrome had glaucoma, and 4.2% had ocular hypertension, whereas the corresponding figures for those without pseudo-exfoliation were 4% and 0.8%, respectively. The high glaucoma rates are partly due to the high pseudo-exfoliation prevalence in the area. The prevalence of the capsular glaucoma increased towards a maximum between 75 and 79 years of age, whereafter the curve declined. This may indicate reduced survival time of glaucomatous patients.

Aged↗
PubMed1991

Frequency distribution of IOP. Analysis of a material using the gamma distribution.

The results of a population-based (age greater than or equal to 65 years) examination of the frequency distribution of IOP are reported. 3726 eyes in 1887 individuals were included in the examination. By consistent use of conventional, well-defined criteria, glaucoma was diagnosed in 6.4% of the individual eyes. In the total material, the average IOP was 18.0 mmHg. Average IOP was 28.7 mmHg in eyes with glaucomatous damage, vs 17.2 mmHg in the normal eyes. Variance of IOP was much higher in the glaucoma group as compared with the normal group. The IOP frequency distribution curve did not fit with a Gaussian curve; it was asymmetric, skewed to the right. The distribution curve obtained by plotting the recorded frequencies was disturbed by irrelevant irregularities, both random and systematic. The irregularities could be evened out by the application of regression analysis, using the equation for the gamma distribution. The IOP frequency distribution is well represented by a gamma distribution curve. The fit is improved by excluding eyes with extremely high and low IOP.

Aged↗