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.

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.

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.

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.

Long-term efficacy of primary laser trabeculoplasty.

Sixty glaucomatous eyes of 60 patients treated with laser trabeculoplasty as primary therapy were reviewed retrospectively. There were 42 eyes with capsular glaucoma and 18 with simple glaucoma. The mean prelaser intraocular pressure (IOP) was 35.2 (SD = 6.5) mmHg. Success was defined as IOP less than or equal to 22 mmHg without medication. The probability of success was 0.73 at 1 year, 0.66 at 2 years, 0.57 at 3 years, and 0.50 at 4 years. Three eyes experienced progressive visual field loss or disc damage in spite of an intraocular pressure below 22 mmHg without medication. High prelaser pressure and the severity of the visual field defects were significant predictors of treatment failure.

Pituitary adenylate cyclase activating polypeptide and nitric oxide synthase are expressed in the rat ciliary ganglion.

AIMS: To study the distribution in the rat ciliary ganglion of neurons synthesising and storing the recently discovered neuropeptide pituitary adenylate cyclase activating polypeptide (PACAP) and neuronal nitric oxide synthase (NOS), the neuronal marker of the novel gaseous transmitter nitric oxide. METHODS: Neurons expressing PACAP and neuronal NOS mRNA were identified in the rat ciliary ganglion by in situ hybridisation with radiolabelled oligonucleotide probes. Immunocytochemistry was used to demonstrate immunoreactive neuropeptides and NOS. RESULTS: Immunocytochemistry demonstrated immunoreactivity for PACAP and NOS in a small number of neuronal cell bodies. In situ hybridisation revealed that NOS and PACAP were expressed in numerous ganglion cell somata. The well established ciliary messengers vasoactive intestinal peptide and neuropeptide Y were found in a large number of neuronal cell bodies. CONCLUSION: These results demonstrate that PACAP and NOS are synthesised and stored in the ciliary ganglion. These findings further illustrate the mixed nature of the ciliary ganglion and may provide a basis for the understanding of the diverse physiological functions of this ganglion.

Primary lasertrabeculoplasty a comparison of 50 spots in 180 degrees and 100 spots in 360 degrees of the trabecular meshwork.

Primary LTP was performed in 20 eyes with 50 spots in 180 degrees and in 26 eyes with 100 spots in 360 degrees of the trabecular meshwork. These eyes had received no earlier glaucoma medication. They were followed prospectively for 12 months. Prelaser IOP was 36.3 +/- 8.0 mmHg in the 50 spot group and 35.9 +/- 6.6 mmHg in the 100 spot group. Treatment was considered successful if IOP was less than or equal to 22 mmHg with no medication and no further disk damage or loss of visual field. The success rate 12 months after LTP was 15% in the 50 spot group and 69% in the 100 spot group.

Orbital CT in the management of blow-out fractures of the orbital floor.

The CT-examinations of 15 patients with blow-out fractures of the orbital floor were reviewed. All patients were examined with coronal/semicoronal CT-imaging, and 7 patients also were evaluated with semisagittal projections. Only in one case the semisagittal images gave more information than coronal sections when using the classification of Gilbard et al. (1985) of the inferior rectus muscle/fracture relationship. The anterior and posterior fracture margins were better delineated with semisagittal imaging. Two patients exhibiting positive traction tests with hooked, and not entrapped muscles on CT still had diplopia 5 1/2 and 12 weeks after the trauma.

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).

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.

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.

Laser trabeculoplasty in open angle glaucoma.

We have treated 54 eyes that were considered candidates for trabeculectomy with argon laser trabeculoplasty. One hundred burns were placed in the trabecular meshwork right in front of the scleral spur in the lower two quadrants. Average prelaser IOP was 26.2 mmHg and average postlaser IOP was 18.3 mmHg. Four eyes (7.4%) went to further surgery. Mean follow-up time was 3.5 months. There were few complications. Most important was a transitory increase of IOP larger than 10 mmHg in 7 eyes (13.0%). There was one case of acute iridocyclitis.

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.

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.

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.

The missing rectus: a CT observation from blow-out fracture of the orbital floor.

A patient with a blow-out fracture of the right orbital floor presented with impediment of the inferior rectus muscle. Coronal CT disclosed a lateral hinged fragment from the orbital floor and herniation of intrabulbar content into the maxillary sinus. The inferior rectus muscle could not be identified intraorbitally in three sequential 3 mm coronal sections and it was concluded that the muscle was incarcerated, a presumption that was verified at surgery.

Retinopathy after low dose irradiation for an intracranial tumor of the frontal lobe. A case report.

A 32-year-old man underwent an operation for an oligodendroglioma of the left frontal lobe. Postoperatively he was irradiated to a target dose of 54 Gy. One year later he developed bilateral retinopathy quite similar to diabetic retinopathy. There were no clinical or biochemical signs of diabetes or hematological disease. The calculated maximum dose to the retina was 11 Gy. This is to our knowledge the lowest retinal dose of ionizing radiation reported to produce retinopathy.