Search PubMedSearch

Biomedical subjects

H Uusitalo

Publications and source records attributed to H Uusitalo.

At least 19 recordsLinked to original sources

Effect of intracameral and intravitreal injection of calcitonin gene-related peptide on the intraocular pressure and outflow facility of aqueous humor in the rabbit.

After intracameral injection calcitonin gene-related peptide has been demonstrated to break the blood aqueous barrier and increase intraocular pressure in rabbits. However in cats, calcitonin gene-related peptide decreases intraocular pressure by increasing the outflow facility of aqueous humor. In the present study, the effect of intracameral injection of calcitonin gene-related peptide on the outflow facility in rabbits has been investigated and the intraocular pressure and outflow facility were measured following intravitreal administration of calcitonin gene-related peptide. The results demonstrate that in spite of the apparent pseudofacility component caused by a breakdown of the blood aqueous barrier also the true trabecular outflow is probably increased in the rabbit eye after intracameral injection of calcitonin gene-related peptide. The intravitreal administration of calcitonin gene-related peptide leaves the blood aqueous barrier intact and causes an increase in the outflow facility of aqueous humor with a concomitant long-lasting decrease in intraocular pressure.

Animals

Production of cartilage collagens during metaphyseal bone healing in the mouse.

Small defects of unfractured bone are believed to heal without a cartilaginous intermediate. We have determined the extent of cartilage production in an experimental model of metaphyseal bone repair involving defects in both cortical and cancellous bone, but no fracture. Northern analyses revealed the presence of mRNAs for type X and II collagens in the repair tissue. Immunohistology confirmed subperiosteal deposition of both collagen types adjacent to the defect. While the mRNAs for the two collagen types peaked by one week of defect healing, immunodetectable type X collagen was not observed until the second week. The data suggest that reactivity of periosteum and activation of chondrogenesis and subsequent endochondral ossification programs are involved in murine bone repair regardless of defect type.

Animals

Binding of CGRP analogs and their effect on adenylate cyclase activity in porcine iris-ciliary body.

The structure-activity relationship of the calcitonin gene-related peptide (CGRP) in the porcine iris-ciliary body was studied using different CGRP analogs. The receptor binding affinity is located mainly in the carboxyterminal end of the CGRP peptide while the ability to stimulate adenylate cyclase (AC) enzyme is mainly in the aminoterminal end of the peptide. The binding of CGRP analogs was also found to be temperature-dependent. Changes in the alpha-helical region or in the beta-turn, as well as replacements of threonine-4, asparagine-25 or asparagine-26, reduce the binding affinity already at +4 degrees C. Truncated aminoterminus, changes in the loop region between cysteines 2 and 7, and especially in threonine 6, have for their part an important role in maintaining AC-stimulating activity.

Adenylyl Cyclases

Lectin binding in normal, scarred, and keratoconus corneas.

PURPOSE: Keratoconus is characterized by central thinning and an increased curvature of cornea. Scarring of cornea accompanies the disease as it proceeds, and the ultimate treatment is keratoplasty. The pathogenesis of keratoconus is still unknown, and therefore we studied normal, keratoconus, and scarred corneas by a panel of lectin conjugates. METHODS: The following lectin conjugates were used: concanavalin A (Con A), Dolichos biflorus agglutinin (DBA), peanut agglutinin (PNA), Ulex europaeus agglutinin (UEA-I), wheat-germ agglutinin (WGA), Helix aspersa agglutinin (HAA), Psophocarpus tetragonolobus agglutinin (PTA), soybean agglutinin (SBA), Griffonia simplicifolia agglutinin-I-B4 (GSA-I-B4), Ricinus communis agglutinin (RCA-I), and Lotus tetragonolobus agglutin (LTA) conjugates, differently recognizing saccharide residues in glycoconjugates. RESULTS: One of the keratoconus corneas was badly scarred, whereas no scars were seen on histopathologic examination in other keratoconus corneas. In all keratoconus corneas, discontinuities or breaks (defects) were seen in the Bowman's layer. DBA and HAA conjugates, both blood group A reactive, reacted with corneal and conjunctival epithelium, blood vessels, and endothelium in blood groups A and AB. The blood group B-reactive GSA-I-B4 conjugate reacted with corneal and conjunctival epithelium, blood vessels, and endothelium only in specimens with blood group B. The blood group O-reactive UEA-I conjugate revealed the apical epithelial cells and blood vessels in all blood groups, whereas LTA conjugate, also blood group O reactive, reacted with all structures in cornea and conjunctiva despite blood groups. HAA and DBA conjugates reacted with defects in keratoconus corneas, SBA and RCA-I conjugates with defect area in keratoconus and scar region in scarred corneas, and PNA and WGA conjugates with the scar region of scarred keratoconus and scarred corneas. No other differences in the binding of lectins between normal, scarred, and keratoconus corneas were seen. CONCLUSIONS: The results indicate that the blood group status influences lectin binding in cornea. Furthermore, the difference in lectin binding to defects in keratoconus corneas (HAA and DBA conjugates) and to scar regions in scarred corneas (PNA and WGA conjugates) suggests that the defects in keratoconus are not solely the results of scarring.

Adolescent

The expression of tenascin and fibronectin in keratoconus, scarred and normal human cornea.

BACKGROUND: The etiology and pathogenesis of keratoconus remain unclear, and therefore we decided to study the distribution of different isoforms of tenascin (Tn) and fibronectin (Fn) in normal human corneas and in those obtained from penetrating keratoplasty for keratoconus and corneal scarring. METHODS: Frozen sections of human cornea and conjunctiva were stained by immunohistochemical methods with a panel of monoclonal antibodies (MAbs) against different isoforms of Tn and Fn. RESULTS: In the normal human eye, Tn was found in the limbal and conjunctival basement membrane region, in the conjunctival blood vessels and at the junction of the cornea and sclera, but no immunoreaction was seen in the normal cornea. In the corneas from the keratoconus patients, a clear immunoreaction for Tn was seen in the defects of Bowman's membrane as well as in the distorted stroma beneath the defects. In some of the keratoconus corneas, basement membrane adjacent to the defects also showed reactivity for Tn, and in clinically and histologically scarred keratoconus corneas the scars expressed Tn. In the scarred corneas, only blood vessels in the posterior portion of the cornea showed immunoreactivity for Tn, while no Tn was noted in the scar area or in Bowman's membrane. No major differences were noticed in the reactivity of different MAbs against Tn isoforms. Fn, extradomain A Fn (EDA-Fn) and oncofetal Fn (onc-Fn) were found in the basement membrane of the central cornea of the normal eye. In keratoconus corneas, the defects and clinical and histological scars bound MAbs against Fn, EDA-Fn and onc-Fn, but in the scarred corneas no enhancement in the expression of Fns was noted. Extradomain B cellular Fn (EDB-Fn) was not expressed in any of the eyes studied. CONCLUSIONS: The results suggest that the anterior portion of the cornea is involved in the pathogenesis of keratoconus. Furthermore, it seems that the expression of Tn and Fns in the clinically scarred keratoconus corneas is due to a process in which both repairing and scar-forming mechanisms operate at the same time. However, the origin of the defects in Bowman's membrane seen in keratoconus still remains unclear. They may be minor scars due to the disease or primary defects in the process leading to keratoconus.

Adolescent

Immunohistochemical distribution of calcitonin gene-related peptide in nerve fibres of the anterior buccal gland of the rat.

Calcitonin gene-related peptide immunoreactive (CGRP-IR) nerves in rat were studied as to their distribution and origin in anterior buccal glands, which are unique minor mucous salivary glands in the rat. A moderate number of CGRP-IR nerve fibres were located, mostly perivascularly and around intralobular ducts, but they were also found around acini. The latter fibres were mainly of sensory origin, as suggested by their disappearance after denervation of the ophthalmic and maxillary branches of the trigeminal nerve. On the contrary, CGRP-IR nerves around interlobular ducts and some of those in a perivascular location remained both after sensory denervation and after extirpation of the sympathetic superior cervical ganglion. Whether these fibres originate in dorsal root ganglia C3-C4 or represent parasympathetic fibres is not known. Based on the present data and the previous findings showing a regulatory role of CGRP both on blood and salivary flow, it is possible that CGRP in sensory, and possibly also in parasympathetic nerves, participates in the regulation of reflex blood flow and salivary secretion in the anterior buccal gland of the rat.

Animals

Intraocular effects of ruthenium red in responses to compound 48/80 and topical formaldehyde in rabbit.

We have previously shown the presence and localization of mast cells and the intraocular effects of compound 48/80 in the rabbit eye. In the present study we have evaluated the mechanism of action of compound 48/80 using ruthenium red as a blocker of sensory axon reflexes in the rabbit eye and by measuring the intraocular pressure (IOP), the pupil size, the blood pressure, the protein and cAMP content in the aqueous humour. Topical neutral formaldehyde was used as a topical inducer of neuronally mediated response in a separate series of experiment. Intracamerally-injected ruthenium red suppressed the compound 48/80-induced elevation intraocular pressure and prevented miosis, while having little if any effect on the breakdown of the blood-aqueous barrier and on the increase in the cAMP concentration in aqueous humour. Ruthenium red also inhibited the irritative response in eyes treated with topical 1% formaldehyde. As the blood-aqueous barrier in the rabbit is an extremely sensitive system higher doses of ruthenium red causes damage of the barrier in the ruthenium red treated eyes. The results demonstrate that compound 48/80 not only has a mast cell degranulating effect but also a sensory nerve- stimulating effect.

Administration, Topical

The immunohistochemical composition of the human corneal basement membrane.

Frozen sections of human cornea and conjunctiva were stained by immunofluorescence and immunoperoxidase methods with a panel of antibodies against various basement membrane (BM) and extracellular matrix proteins to study the composition of the human corneal BM. Laminin (Ln) immunoreactivity was detected in the BMs of the blood vessels and conjunctival, limbal, and corneal epithelia by using a polyclonal antiserum and monoclonal antibodies (MAbs) against Ln chains alpha 1, beta 1, and gamma 1, but in the cornea the reaction with MAbs against alpha 1, beta 1, and gamma 1 chains was clearly weaker than in the other BMs and in some sections totally absent. Immunoreactivity to Ln alpha 2 chain was detected only in the BM of the limbus, whereas Ln beta 2 chain was detected in the BMs of blood vessels and that of conjunctival and limbal epithelia. Ln-5 and Ln alpha 3 and beta 3 chains were seen in the BMs of the corneal, limbal, and conjunctival epithelia coaligning the integrin beta 4. Immunoreactivity for collagen type IV was lacking in the BM of the corneal epithelium, but present in the BMs of the limbal and conjunctival epithelia as well as in the vascular BM. Collagen type VII immunoreactivity was seen in the BM areas of the corneal, limbal, and conjunctival epithelia. BMs of corneal, limbal, conjunctival, and vascular epithelia expressed fibronectin (Fn), including extradomain A cellular Fn and oncofetal cellular Fn isoforms, all lacking, however, extradomain B cellular Fn. The present results give new information on the Ln chain distribution and show that the BM of the corneal epithelium differs from that of surrounding epithelia by the lack of collagen type IV.

Adolescent

Neutral endopeptidase (EC 3.4.24.11) in labial salivary glands in healthy controls and in patients with Sjögren's syndrome.

OBJECTIVE: Neuropeptides from nerve fibres can cause neurogenic inflammation. The potency of these peptides in vitro has led to the hypothesis that enzyme degradative systems are operative in vivo to limit their action. To consider this question neutral endopeptidase (NEP) in labial salivary glands in patients with Sjögren's syndrome was studied. METHODS: Synthesis of NEP mRNA in situ in labial salivary glands was studied using the reverse transcriptase polymerase chain reaction (RT-PCR). Immunohistochemical staining was used to localise the NEP enzyme protein and its neuropeptide substrates and fluorophotometry to measure the corresponding enzyme activities in saliva. RESULTS: NEP was found in nerve fibres and in perivascular, periductal, and periacinar axon terminal varicosities. Double labelling of PGP 9.5 and NEP confirmed this neuronal localisation of NEP. Although some fibroblast-like cells and occasional intravascular neutrophils were NEP positive, NEP mRNA was not found in labial salivary glands. Patients with Sjögren's syndrome and healthy controls did not have nerves containing NEP or neuropeptides (vasoactive intestinal peptide, substance P, or calcitonin gene related peptide (CGRP)) in lymphocyte foci. Salivary NEP activity was not decreased in patients compared with controls. CONCLUSION: NEP in labial salivary glands is almost totally of neuronal origin and plays a part in proteolytic modulation of neuropeptides in salivary glands and saliva. These regulatory interactions seem to be altered in focal lymphocyte accumulations in Sjögren's syndrome.

Base Sequence

Calcitonin gene-related peptide (CGRP) and its effects on protein release in vitro in the developing submandibular gland of the rat.

Indirect immunohistochemical methods were used to study presence and number of CGRP-immunoreactive (CGRP-IR) nerve fibers in the submandibular gland and ganglion cells of the superior cervical, submandibular and trigeminal ganglia of the developing rat. The effect of CGRP on peroxidase and total protein release was also studied in the developing postnatal submandibular glands of 1, 5, 12 and 30-day-old, as well as adult rats by in vitro methods. The possible costimulation of CGRP with SP, NKA or carbachol on 5-day-old and adult rats was also tested. The stimulatory effects of these compounds were compared to the basic release of peroxidase and total amount of proteins from submandibular gland fragments in incubation solution. CGRP-IR nerve fibers were found in relatively high number during post-natal development, mainly around blood vessels and ducts. Some CGRP-IR nerve fibers were also detected around acini. The number of these fibers was quite low and remained constant during the post-natal development. The number of CGRP-IR trigeminal ganglion cells was higher on the 5th and 12th post-natal day than later in development and in adult animals. At the same time, superior cervical- and submandibular ganglion cells were non-reactive for CGRP, suggesting trigeminal origin of CGRP-IR nerve fibers during the development in the submandibular gland. In the secretory studies, CGRP per se stimulated both peroxidase and total protein release in the submandibular gland most effectively on 5th and 12th post-natal days, while there was no clear secretory response in the adult glands. In the 5-day-old submandibular gland CGRP in combination with SP, NKA or carbachol clearly enhanced the total protein secretory response when compared with the release caused by these substances alone. However, in the adult submandibular gland, the combinations did not enhance total protein release more than any of the substances alone. Furthermore, it can be concluded that the presence of a more dense CGRP-IR innervation during the early postnatal period in the developing submandibular gland is accompanied with an increased responsiveness of the secretory elements to CGRP.

Aging

Effect of captopril on ocular irritative response to topical neutral formaldehyde and YAG-laser capsulotomy in the rabbit.

Angiotensin converting enzyme (ACE) -inhibitors inhibit degradation of inflammatory mediators substance P (SP) and bradykinin, which may further stimulate the synthesis of prostaglandins. The resulting increase in inflammatory mediators in tissues is suggested to be the reason for the dry cough, involving sensory C-fiber activation, among patients receiving ACE-inhibitor therapy. In the present study, the effect of an ACE-inhibitor, captopril, on ocular irritative responses was studied in the rabbit. Intravenous captopril decreased markedly the blood pressure and the intraocular pressure (IOP) modestly. Topical neutral formaldehyde elicits an irritative response in the eye mediated through sensory neuropeptides SP and calcitonin gene-related peptide (CGRP). Following topical neutral formaldehyde, the increase in IOP and breakdown of the blood-aqueous barrier were inhibited by captopril, while miosis was not affected. Cyclic AMP (cAMP) content in the aqueous humour was increased by captopril, and this increase was inhibited by indomethacin. Following YAG-laser anterior capsulotomy, captopril inhibited the increase in IOP, breakdown of the blood-aqueous barrier and miosis. The present study demonstrates that use of short-term administration of captopril prior to sensory nerve stimulation or YAG laser anterior capsulotomy does not enhance the ocular responses to these stimuli in the rabbit. In the present study, captopril inhibited these responses, at least partly by decreasing the blood pressure.

Administration, Topical

Localization of calcitonin gene-related peptide binding sites in the eye of different species.

The localization of calcitonin gene-related peptide (CGRP) binding sites in the eye of monkey, pig, cat and guinea pig was studied by autoradiography. Specific binding of CGRP was found in ciliary muscle, ciliary processes and limbal conjunctiva in all tested species. Furthermore, specific binding sites of CGRP was found in the choroidea of monkey, pig and guinea pig, in the iris of pig, cat and guinea pig, in the retina of pig and in the anterior chamber angle of cat. The number of specific binding sites varied depending on the tissue and species. The present study shows that there are specific binding sites of CGRP in the eye of monkey, pig, cat and guinea pig. CGRP binding sites found in vascular system of ciliary body, choroidea and iris further demonstrates the role of CGRP as a vasoregulatory peptide. Binding sites in the ciliary muscle, in the limbal conjunctiva and in the chamber angle area may indicate a role in the regulation of ciliary muscle tone, epithelial cell regeneration and aqueous humour outflow.

Animals

Production and characterization of a monoclonal antibody against human calcitonin gene-related peptide (CGRP) and its immunohistochemical application to salivary glands.

A monoclonal antibody (mAb), 129CD8 was raised against a C-terminal fragment (aa28-37) of alpha-human calcitonin gene-related peptide (CGRP) coupled to bovine serum albumin. The specificity of the monoclonal antibody 129CD8 was corroborated by dot immunobinding experiments, enzyme-linked immunoassay and immunostaining of tissue sections. In vitro studies showed that the mAb 129CD8 readily recognized the fragment 28-37 of alpha-human CGRP and to a slightly lesser degree whole alpha-human CGRP and the fragments containing the C-terminal part of the molecule. The mAb 129CD8 also recognized the beta-human CGRP but not the alpha-rat CGRP. The mAb 129CD8 did not react with substance P, katacalcin, calcitonin, amylin or fragments of alpha-human CGRP lacking the C-terminal part of the molecule. Immunocytochemical staining was performed on human skin, guinea-pig thyroid and salivary glands and the trigeminal ganglion, and rat thyroid gland. Our findings demonstrate, in keeping with previous studies, that in human skin, nerve fibres containing CGRP immunoreactivity are found in both epidermis and dermis. In accordance with previous investigators, the Merkel cells were immunoreactive for CGRP. In the guinea-pig and rat thyroid gland CGRP immunoreactivity was localized in the C-cells. The distribution of CGRP immunoreactivity in the guinea-pig salivary glands is different from that previously reported for rat salivary glands. In the guinea-pig trigeminal ganglion, CGRP immunoreactivity was localized mainly in small-sized neurons and fibres traversing the ganglion.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals

The sympathetic and parasympathetic nature of neuropeptide Y-immunoreactive nerve fibres in the major salivary glands of the rat.

The distribution and origin of neuropeptide Y in the major salivary glands of the rat was studied by indirect immunofluorescence technique. Numerous nerve fibres immunoreactive for the peptide were seen in the parotid and sublingual glands. Most of the fibres were located around blood vessels and salivary acini. In the submandibular gland the number of immunoreactive nerve fibres around the acini was lower in comparison with that in the parotid and sublingual glands. Some immunoreactive nerve fibres were also found around or along intra- and interlobular ducts in all major salivary glands. A large number of the neuropeptide-containing neuronal cell bodies and nerve fibres were detected in the sympathetic superior cervical ganglion. Sympathetic postganglionic nerve trunks of this ganglion contained numerous immunoreactive nerve fibres as well. A subpopulation of the neuronal cell bodies in the submandibular ganglion were immunoreactive to neuropeptide Y. Both uni- and bilateral superior cervical ganglionectomies caused a significant decrease in the number of immunoreactive nerve fibres around the blood vessels in all the major salivary glands. However, these denervations did not affect the density of nerve fibres around the acini and ducts. On the contrary, unilateral parasympathetic denervation by sectioning the auriculotemporal nerve reduced the fibres around the secretory acini in the parotid gland remarkably, while only a minor reduction in the density of immunoreactive fibres associated with the blood vessels of the gland was detected. Unilateral electrocoagulation of the trigeminal nerve branches caused no detectable change in the density of immunoreactive nerve fibres in any of the major salivary glands.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals

The distribution and origin of nerve fibers immunoreactive for substance P and neurokinin A in the anterior buccal gland of the rat.

The distribution and origin of substance P (SP) and neurokinin A (NKA) were studied in rat in the anterior buccal glands, which are minor mucous salivary glands. Indirect immunofluorescence staining showed moderate SP and NKA innervation of salivary acini and interlobular ducts, whereas blood vessels were more sparsely innervated, and there were few nerve fibers in the stroma and around the intralobular ducts. About 10%-20% of the trigeminal ganglion cells showed equally strong immunoreactivity to both SP and NKA. Unilateral denervation of the branches of the trigeminal nerve caused complete disappearance of the stromal fibers and greatly reduced the number of all other SP-immunoreactive and NKA-immunoreactive nerve fibers. In the superior cervical ganglia, SP and NKA immunoreactivity was restricted to small intensely fluorescent cells; SP and NKA immunoreactivity was absent from principal ganglionic cells, and thus sympathectomy had no any effect on the number or distribution of fibers immunoreactive for SP and NKA in the anterior buccal glands. The fibers remaining after sensory denervation could have been of parasympathetic origin, indicating a dual origin of nerves immunoreactive for SP and NKA in these glands. The present data demonstrate that the major part of the glandular SP and NKA innervation in the minor salivary glands derives from the trigeminal ganglia. The distribution of the peripheral nerve fibers indicates that they may play a role in the delivery of potent neuropeptides involved in the vascular, secretory, and motor (myoepithelial cells) functions of salivary glands.

Animals

Characterization of binding sites and effects of calcitonin gene-related peptide (CGRP) and CGRP 8-37 on regional blood flow in rabbit salivary glands.

Calcitonin gene-related peptide (CGRP) is a neuropeptide present in nerve fibres of salivary glands in several species, including man. One of the major targets of these nerve fibres are blood vessels of the glands. The presence and distribution of specific binding sites for CGRP in the rabbit major salivary glands was here investigated autoradiographically. In order to determine the physiological role of CGRP, regional blood flow was measured after intravenous (i.v.) or intra-arterial (i.a.) administration of CGRP or the antagonist CGRP 8-37, using a microsphere technique. Specific binding sites for CGRP were found in the parotid, submandibular and sublingual glands, distributed mainly in the muscular and endothelial layers of the blood vessel walls. CGRP injected i.a. (10 pmol/kg) caused a significant increase in regional blood flow in all major salivary glands. However, i.v. infusion of CGRP (120 pmol/kg) decreased regional blood flow in the parotid and sublingual glands, due to a general decrease in peripheral resistance and redistribution of peripheral blood flow. CGRP 8-37 given i.a. together with CGRP significantly inhibited the blood-flow increase by CGRP alone. It is concluded that most of the CGRP receptors in the rabbit salivary glands are localized in vascular elements. The physiological data show that CGRP acts as a vasodilator in the major salivary glands of the rabbit in vivo, and that the effect of CGRP is inhibited by the CGRP antagonist CGRP 8-37.

Analysis of Variance

Substance P (SP) and neurokinin A (NKA) in developing submandibular glands of the rat.

The effect of isoprenaline, carbachol, substance P (SP) and neurokinin A (NKA) on peroxidase and total protein secretion was studied in the developing postnatal submandibular glands of the rat using in vitro methods. Submandibular glands of 1, 5, 12 and 30 day-old rats were stimulated by 10(-5) M isoprenaline and carbachol, and 10(-6) M SP and NKA. The stimulatory effects of these compounds were compared to the basic release of peroxidase and total amount of protein from submandibular gland fragments in incubation solution with no added transmitter substances. Indirect immunohistochemical methods were used to study these developing glands from SP- and NKA-immunoreactive (IR) nerve fibers. The distributions of SP-IR and NKA-IR nerve fibers closely resembled each other, being most abundantly spread around the developing acini and ducts. The number of these fibers was high on the 1st, 5th and 12th days, but was decreased on the 30th day. On peroxidase release, isoprenaline was the most effective, causing a maximal response of 47 times the basic release on the first postnatal day, after which it gradually decreased. The effects of carbachol, SP and NKA on peroxidase release were clearly weaker and, unlike isoprenaline, their strongest response was on the 5th postnatal day (carbachol, 4.3; SP 5.2; NKA, 4.5). The total protein secretion effect patterns of the studied substances resembled each other more, showing their strongest response on the 5th day (isoprenaline, 5.0; carbachol, 4.5; SP, 4.2; NKA, 3.4) and decreasing thereafter.(ABSTRACT TRUNCATED AT 250 WORDS)

Absorption