RESUMO
Argentophilic staining and scanning electron microscopy were used to study the tegumentary papillae of Echinostoma caproni cercariae. The most abundant tegumentary papillae were uniciliate, but multiciliate papillae were also found, mainly on the ventral aspect of the oral collar. The distribution pattern of the papillae on the body and tail was in general similar to that seen in the cercariae of other 37-collar-spined Echinostoma species. Some differences were noted between E. caproni and the allopatric species, E. trivolvis. E. caproni has a greater number of papillae associated with the collar spines than does E. trivolvis. E. caproni has uniciliate papillae on the acetabulum, whereas E. trivolvis does not. Chaetotaxy is useful to distinguish subtle morphological differences in cercarial species in the 37-collar-spined Echinostoma complex.
Assuntos
Echinostoma/crescimento & desenvolvimento , Echinostoma/ultraestrutura , Animais , Echinostoma/classificação , Estágios do Ciclo de Vida , Microscopia Eletrônica de Varredura/métodos , Caramujos/parasitologia , Coloração e RotulagemRESUMO
Glutathione, which is found in high levels in eye tissues, is involved in multiple functions, including serving as an antioxidant and as an electron donor for peroxidases. Although the activities of enzymes related to glutathione metabolism have been reported in the eye, the issue of which cells produce these proteins, where they are produced and at what levels is an important one. Glutathione reductase, an enzyme which recycles oxidized glutathione by transferring electrons from NADPH, was localized immunohistochemically in adult rat eye in this study. The reductase was distributed in the corneal and conjunctival epithelia, corneal keratocytes and endothelium, iridial and ciliary epithelia, neural retina, and retinal pigment epithelium. In addition, it was highly expressed in ganglion cells, which are responsible for transmitting photophysiological signals from the retina to the higher visual centres. To clarify the correlation of glutathione reductase expression and oxidative stress, the enzymatic activity and the level of protein expression at the pre- and postnatal stages was examined. Expression of the enzyme was detected first in the ganglion cell layer of a late prenatal stage, and appeared in the inner plexyform layer after birth. Along with an increasing differentiation between the inner nuclear and outer nuclear layers, glutathione reductase expression became detectable in the outer plexyform layer. Pigment epithelial cells were positively stained only after birth. Expression was also detected in the lens epithelium from the prenatal to early postnatal stages although its level was low in the adult lens. Collectively, these data, except for lens epithelia, suggest the pivotal role of glutathione reductase in recycling oxidized glutathione for the protection of the tissues against oxidative stress, which is caused by eye opening accompanied by the initiation of various ocular processes, such as accession of light and transduction of the photochemical signal.
Assuntos
Olho/enzimologia , Olho/crescimento & desenvolvimento , Glutationa Redutase/metabolismo , Retina/enzimologia , Animais , Antioxidantes/química , Antioxidantes/metabolismo , Olho/embriologia , Immunoblotting , Imuno-Histoquímica , Ratos , Ratos Wistar , Proteínas Recombinantes/metabolismo , Retina/embriologia , Retina/crescimento & desenvolvimento , Extratos de TecidosRESUMO
The 37-collar-spined echinostomes Echinostoma paraensei, E. caproni, and E. trivolvis are digeneans that live in the intestine of small mammals and birds. Comparative studies of the eggs of these species were done using light microscopy (LM), scanning electron microscopy (SEM), and transmission electron microscopy (TEM). The egg of E. caproni was the largest of the three species studied, whereas the egg of E. trivolvis was the smallest in both length and width. The SEM study showed differences in the aboperculum region of the eggs in all three species. The TEM study showed that the eggshell of all three species consisted of three layers, but no difference in eggshell structure was observed in any species.
Assuntos
Echinostoma , Óvulo/ultraestrutura , Animais , Echinostoma/classificação , Echinostoma/fisiologia , Microscopia EletrônicaRESUMO
We examined numerous ovarian follicles from 32-35 d virgin mice by transmission electron microscopy and light microscopic immunohistochemistry. No macrophages were seen, but various stages of apoptotic granulosa cells were encountered. Presumably a granulosa cell or its debris in an advanced stage of apoptosis was destined to be phagocytosed by adjacent normal-looking granulosa cells. Other granulosa cells of normal appearance were seen in the region of the zona pellucida in contact with and apparently phagocytosing atrophic oocytes. Such granulosa cells were characterised by the presence of gap junctions with other cells and frequently contained annular gap junctions in the cytoplasm. To confirm the lack of involvement of macrophages in the process of follicular atresia and elimination, specially prepared ovarian sections were incubated with antimouse macrophage monoclonal antibodies (F4/80, Mac-1, Mac-2). None of the follicles examined showed positive immunoreactivity with these antibodies. Atretic follicles may shrink and eventually disappear from the ovary as a result of repeated apoptosis and phagocytosis by granulosa cells. There is no evidence for the presence or involvement of macrophages in the atretic follicles, at least in prereproductive mice as examined.
Assuntos
Folículo Ovariano/anatomia & histologia , Animais , Apoptose , Feminino , Imuno-Histoquímica , Camundongos , Microscopia Eletrônica , Folículo Ovariano/ultraestruturaRESUMO
A comparative ultrastructure study using transmission electron microscopy (TEM) of ultrathin sections, freeze-fracture replication, and scanning electron microscopy (SEM) was conducted on the gastrodermal lamellar microvilli in adults of Echinostoma paraensei, E. caproni, and E. trivolvis. Lamellar projections observed by SEM were mainly planiform and rhomboidal or paddle-shaped, and they were commonly seen in the three species. The distal margins of these lamellae were mainly smooth in E. paraensei, whereas filiform or digitiform extensions in the margins occurred occasionally in E. caproni and frequently in E. trivolvis. Freeze-fracture TEM elucidated significant interspecific differences in the numbers of intramembranous particles (IMP) per square micrometer; the numbers of IMP were significantly lower in E. trivolvis than in either E. caproni or E. paraensei. Thus, ultrastructural differences in the gastrodermal lamellae of adult echinostomes will be a taxonomically useful criterion for distinguishing species of Echinostoma.
Assuntos
Echinostoma/ultraestrutura , Animais , Cricetinae , Intestinos/ultraestrutura , Masculino , Mesocricetus , MicrovilosidadesRESUMO
The luminal surface of the rod photoreceptor disk membrane was exposed by means of osmotic shock and labeled with ferritin- conjugated concanavalin A. The structural changes of the luminal surface were examined by a freeze-etching procedure with cryoprotectant (methanol). On replicas from freeze-etched membranes with concanavalin A labeling, 6- to 10-nm particles were codistributed with ferritin particles on the luminal surface of the disk membrane. By contrast, there were few ferritin particles or less numerous 6- to 10-nm particles on the corresponding surface without concanavalin A labeling. If 6- to 10-nm particles corresponded to the carbohydrate moiety of rhodopsin, concanavalin A binding might tend to preserve this carbohydrate moiety. These results suggest that the two-dimensional analysis of lectin-induced structural changes of the membrane surface glycoconjugates may become available by lectin cytochemistry combined with freeze-etching.
Assuntos
Segmento Externo da Célula Bastonete/ultraestrutura , Animais , Sítios de Ligação/fisiologia , Membrana Celular/metabolismo , Membrana Celular/ultraestrutura , Concanavalina A/metabolismo , Concanavalina A/farmacocinética , Ferritinas/metabolismo , Técnica de Congelamento e Réplica , Histocitoquímica , Lampreias , Microscopia Eletrônica , Tamanho da Partícula , Segmento Externo da Célula Bastonete/metabolismoRESUMO
We have previously reported a complete lack of circadian rhythm in the body temperature of pikas in contrast to other lagomorphs. In this present study, the anatomical and neurochemical findings by immunohistochemical, photo and electron microscopic methods reveal that the photoreceptor system of this animal is poorly developed. This probably explains their stable core body temperature which help them survive in cold temperatures.
Assuntos
Temperatura Corporal/fisiologia , Ritmo Circadiano/fisiologia , Retina/anatomia & histologia , Retina/química , Animais , Bovinos , Galinhas , Cyprinidae , Lagomorpha , Microscopia Eletrônica , Células Fotorreceptoras/química , Células Fotorreceptoras/ultraestrutura , Rana catesbeiana , Ratos , Retina/ultraestrutura , Suínos , TartarugasRESUMO
CDP-diacylglycerol (CDP-DAG) synthase (CDS) is known as one of the key enzymes in the lipid synthesis including phosphoinositides (PIs) production. Phosphatidylinositol (PtdIns) synthase (PIS) catalyzes a formation of PtdIns from CDP-DAG in the PI cycle which produces several second messengers. We compared the gene expression for a presumably PI cycle specific-CDS molecule and a PIS using Northern blot analysis and in situ hybridization histochemistry in the central nervous system (CNS) and retina of developing and mature rats. Whereas no significant expression for CDS was detected during the prenatal stage in any CNS regions, PIS mRNA had already expressed on the prenatal day 15 throughout the neuroaxis including the spinal cord. During the postnatal stages, the gene expression for both CDS and PIS was detected widely in the gray matters throughout the entire brain. The expression for CDS was at higher levels in the olfactory mitral cells, the occipital cortex, the subiculum and hippocampal CA1 pyramidal cells, and the cerebellar Purkinje cells. On the other hand, the expression for PIS was at high levels in the olfactory mitral cells, the cerebral cortex, the hippocampal and dentate neuronal layer and the cerebellar Purkinje and granule cells. No significant expression for CDS or PIS was detected in the ventricular germinal zone, the cerebellar external granular layers, the mature ependyma or entire white matters. The expression for CDS and PIS decreased slightly throughout the CNS on P49. The significance of the parallel and discrepant expression patterns in terms of relative intensity between the two enzyme molecules was discussed in relation to the membrane turnover and signal transduction.
Assuntos
Encéfalo/enzimologia , Diacilglicerol Colinofosfotransferase/genética , Regulação da Expressão Gênica no Desenvolvimento , Retina/enzimologia , Transcrição Gênica , Transferases (Outros Grupos de Fosfato Substituídos)/genética , Animais , Encéfalo/embriologia , Encéfalo/crescimento & desenvolvimento , CDP-Diacilglicerol-Inositol 3-Fosfatidiltransferase , Feminino , Regulação Enzimológica da Expressão Gênica , Proteínas de Membrana , Especificidade de Órgãos , Gravidez , RNA Mensageiro/análise , Ratos , Ratos Wistar , Retina/embriologia , Retina/crescimento & desenvolvimento , Medula Espinal/embriologia , Medula Espinal/enzimologia , Medula Espinal/crescimento & desenvolvimentoRESUMO
To investigate immunological environment in the cerebrospinal fluid (CSF) system, ultrastructural and three-dimensional localization of intercellular adhesion molecule-1 (ICAM-1) was studied in the choroid plexus, arachnoid membrane and dural sinus of LPS-stimulated rats with immuno-SEM and TEM. The choroid plexus epithelial cells expressed rich ICAM-1 along the microvilli. The arachnoid trabeculae fibroblast-like cells demonstrated ICAM-1 expression on both sides facing the subarachnoid space moderately. The dural sinus endothelial cells, however, showed only few ICAM-1 expression and no specific localization. These results suggest that the choroid plexus and arachnoid membrane may play an important mutual role for leukocyte migration in the CSF system, and that the CSF system may function in immunoreaction independently of the vascular system with the aid of up-regulated ICAM-1 expression.
Assuntos
Aracnoide-Máter/metabolismo , Ventrículos Cerebrais/metabolismo , Plexo Corióideo/metabolismo , Cavidades Cranianas/metabolismo , Molécula 1 de Adesão Intercelular/metabolismo , Lipopolissacarídeos/toxicidade , Animais , Aracnoide-Máter/patologia , Aracnoide-Máter/ultraestrutura , Ventrículos Cerebrais/patologia , Ventrículos Cerebrais/ultraestrutura , Plexo Corióideo/patologia , Plexo Corióideo/ultraestrutura , Cavidades Cranianas/patologia , Cavidades Cranianas/ultraestrutura , Feminino , Inflamação/metabolismo , Inflamação/patologia , Injeções Intraventriculares , Microscopia Eletrônica de Varredura , Microscopia Imunoeletrônica , Ratos , Ratos Endogâmicos LewRESUMO
A drastic change in the outer membrane structure of a salt-sensitive soil bacterium, S34, related to the genus Deinococcus was induced by 0.2 to 0.4% (wt/vol) NaCl. The change was relieved by 6 mM CaCl2 and induced by 1 mM EGTA. The results indicate the strong dependence of the organism on calcium.
Assuntos
Cálcio/fisiologia , Micrococcaceae/efeitos dos fármacos , Micrococcaceae/crescimento & desenvolvimento , Sódio/farmacologia , Cloreto de Cálcio , Membrana Celular/efeitos dos fármacos , Membrana Celular/ultraestrutura , Micrococcaceae/ultraestrutura , Cloreto de Sódio , Microbiologia do SoloRESUMO
A cDNA encoded a 462-amino acid protein, which showed CDP-diacylglycerol synthase (CDS) activity was cloned for the first time as the vertebrate enzyme molecule from rat brain cDNA library. The deduced molecular mass of this rat CDS was 53 kDa, and putative primary structure included several possible membrane- spanning regions. At the amino acid sequence level, rat CDS shared 55.5%, 31. 7%, and 20.9% identity with already known Drosophila, Saccharomyces cerevisiae, and Escherichia coli CDS, respectively. This rat CDS preferred 1-stearoyl-2-arachidonoyl phosphatidic acid as a substrate, and its activity was strongly inhibited by phosphatidylglycerol 4, 5-bisphosphate. By immunoblotting analysis of COS cells overexpressed with the epitope-tagged for rat CDS, a 60-kDa band was detected. By epitope-tag immunocytochemistry, the CDS protein was mainly localized in close association with the membrane of the endoplasmic reticulum of the transfected cells. The intense mRNA expression of CDS was localized in the cerebellar Purkinje cells, the pineal body, and the inner segment of photoreceptor cells. Additionally, very intense expression was detected in postmitotic spermatocytes and spermatids.
Assuntos
Encéfalo/enzimologia , Diacilglicerol Colinofosfotransferase/genética , Sequência de Aminoácidos , Animais , Sequência de Bases , Células COS , Diacilglicerol Colinofosfotransferase/química , Hibridização In Situ , Masculino , Dados de Sequência Molecular , Fosfatidilinositol 4,5-Difosfato/metabolismo , RNA Mensageiro/metabolismo , Ratos , Ratos Wistar , Retina/enzimologia , Testículo/enzimologiaRESUMO
Peanut agglutinin (PNA) was known for its selective binding to cone cells. In the present study, we investigated whether there was any difference in PNA binding among various subtypes of cone photoreceptor cells in the dace retina. The outer segments of the long-double- and long-single-cone cells were preferentially labeled with PNA. Ultrastructural pre-embedding labeling revealed that the binding sites of PNA were confined to the calycal processes of these cells. By contrast, only slight labeling was discerned on the corresponding regions of other types of cone cells. The results indicate that PNA can distinguish the long-wavelength-sensitive cone from the short-to-middle-wavelength-sensitive cone cells.
Assuntos
Peixes/anatomia & histologia , Retina/citologia , Células Fotorreceptoras Retinianas Cones/citologia , Animais , Adaptação à Escuridão , Histocitoquímica , Lectinas , Microscopia Eletrônica , Células Fotorreceptoras Retinianas Cones/ultraestruturaRESUMO
A visual pigment was extracted from lamprey retina and was expressed in cultured mammalian cells (293S) using a cDNA fragment isolated from lamprey retina. The extracted pigment, a putative lamprey rhodopsin, had an absorption maximum at 503 nm. The recombinant lamprey rhodopsin, reconstituted with 11-cis-retinal, showed an absorption maximum at about 500 nm. Both pigments reacted with an anti-bovine rhodopsin antibody (Rh29), which recognizes the short photoreceptor cells in lamprey retina. Unlike rhodopsins of higher vertebrates, the lamprey rhodopsin bleached gradually in the presence of 100 mM hydroxylamine even in the dark. Our results suggest that, despite its high similarities with other vertebrate rhodopsins, lamprey rhodopsin has a character different from those of higher vertebrates.
Assuntos
Retina/metabolismo , Rodopsina/química , Animais , Bovinos , Linhagem Celular , Cromatografia Líquida de Alta Pressão , Clonagem Molecular , Lampreias , Proteínas Recombinantes/química , Proteínas Recombinantes/genética , Proteínas Recombinantes/isolamento & purificação , Rodopsina/genética , Rodopsina/isolamento & purificação , Análise EspectralRESUMO
Seven types of ferritinized lectin were used to examine the distribution of glycoconjugates on the outer segment membranes of lamprey photoreceptor cells. Ultrastructural pre-embedding labeling revealed that peanut agglutinin, soybean agglutinin and Ricinus communis agglutinin I were preferentially bound to the proximal, lateral and luminal surfaces of the long cell outer segments, whereas Griffonia simplicifolia agglutinin II and concanavalin A agglutinin were bound to the corresponding surfaces of the short cell outer segments. The results indicate that there is marked difference in the composition of glycoconjugates over the outer segment membranes between long and short photoreceptors.
Assuntos
Glicoconjugados/análise , Lampreias/metabolismo , Células Fotorreceptoras/química , Animais , Sítios de Ligação , Lectinas , Microscopia Eletrônica , Células Fotorreceptoras/ultraestruturaRESUMO
Immunolocalization of K(AB)-2 (Kir4.1), an inwardly rectifying K+ channel with a putative ATP-binding domain, was examined in rat kidney where expression of K(AB)-2 mRNA was previously shown. Anti-K(AB)-2 antibody was raised in rabbit and then affinity-purified. An immunohistochemical study revealed that K(AB)-2 immunoreactivity was detected specifically in the basolateral membrane of distal tubular epithelia. Therefore, K(AB)-2 is the first K+ channel shown to be localized in the basolateral membrane of renal epithelia. The finding suggests that K(AB)-2 may contribute to supplying K+ to the Na(+)-K+ pump, which is abundant in the basolateral membrane of distal tubular epithelia, as well as to maintenance of the deep negative membrane potential of these cells.
Assuntos
Túbulos Renais Distais/química , Canais de Potássio Corretores do Fluxo de Internalização , Canais de Potássio/análise , Sequência de Aminoácidos , Animais , Especificidade de Anticorpos , Membrana Celular/química , Epitélio/química , Córtex Renal/química , Masculino , Dados de Sequência Molecular , Oligopeptídeos/síntese química , Oligopeptídeos/imunologia , Coelhos , Ratos , Ratos WistarRESUMO
The apical surface of the guinea-pig organ of Corti was examined with SEM after WGA-lectin histochemistry which has a binding specificity for sialic acid and N-acetyl-glucosamine. The contrast of colloidal gold markers were particularly enhanced by back-scattered electron imaging. WGA lectin showed remarkable preference for the microvilli as well as flat surface areas in the supporting cells. Stereociliary surfaces and interstereociliary connections of the sensory hair cell were strongly labelled, whilst only rarely the markers were found in the flat areas of the apical surface of the hair cell. The connections, which are known to be involved in the initiation of the mechanoelectrical transduction, should consist of sialic acid and/or N-acetyl-glucosamine.
Assuntos
Microscopia Eletrônica de Varredura/métodos , Órgão Espiral/metabolismo , Órgão Espiral/ultraestrutura , Aglutininas do Germe de Trigo/metabolismo , Acetilglucosamina/metabolismo , Animais , Sítios de Ligação , Elétrons , Cobaias , Células Ciliadas Auditivas/metabolismo , Células Ciliadas Auditivas/ultraestrutura , Masculino , Microvilosidades/metabolismo , Microvilosidades/ultraestrutura , Ácido N-Acetilneuramínico , Espalhamento de Radiação , Ácidos Siálicos/metabolismoRESUMO
The cone matrix sheath is a biochemically and structurally distinct domain of the retinal interphotoreceptor matrix (IPM). In the present study, the insoluble components of the cone matrix sheath were extracted from bovine retina, and examined for pH-dependent morphological changes by light and electron microscopy. After soaking unfixed retinas in 25 mM HEPES-buffered solution (pH 2.0), sheets of aqueous-insoluble IPM containing cone matrix sheaths were physically dissociated from the inner retina. The insoluble IPM preparations were treated with 1.0% Triton X-100 to extract contaminating photoreceptor outer segment membrane, and exposed to HEPES-buffered solutions at pH 2.0, 4.5, 7.0, or 9.5. The cone matrix sheath, specifically stained with peanut agglutinin, appeared finely granular at pH 2.0, but was markedly condensed at pH 4.5. Cone sheath morphology became dispersed and appeared as a network of thick fibrils at pH 7.0, and further dispersed fibrillar and granular elements at pH 9.5. These findings suggest that pH changes in the interphotoreceptor space can alter the molecular organization of the IPM and influence the function of the IPM in the transport of nutrients and metabolites, and in retinal adhesion.
Assuntos
Matriz Extracelular/ultraestrutura , Células Fotorreceptoras Retinianas Cones/ultraestrutura , Animais , Arachis , Soluções Tampão , Bovinos , Matriz Extracelular/efeitos dos fármacos , Matriz Extracelular/fisiologia , HEPES/farmacologia , Concentração de Íons de Hidrogênio , Lectinas/metabolismo , Aglutinina de Amendoim , Lectinas de Plantas , Células Fotorreceptoras Retinianas Cones/efeitos dos fármacos , Células Fotorreceptoras Retinianas Cones/fisiologiaRESUMO
Three-dimensional localization of the intercellular adhesion molecule-1 (ICAM-1) in the corneal endothelium stimulated by Salmonella typhimurium endotoxin was investigated using immuno-scanning electron microscopy (SEM). Samonella typhimurium endotoxin, 100 micrograms, was injected in Lewis rats weighing 200 grams. The animals, including the controls, were sacrificed and both eyes enucleated at 0, 3, 12 and 24 hours after injection (n = 3 each time). After resection, the corneas were immersed in hypothermic University of Wisconsin solution with monoclonal mouse-anti-rat ICAM-1 IgG and then goat-anti-mouse IgG coupled to 15 nm gold particles. Then the corneas were prepared conventionally for scanning electron microscopy. Histotopographical examination with immuno-SEM revealed that ICAM-1 antigen increased on the corneal endothelium by 3 hours postinjection. The particles were arranged along the cytoplasmic processes, especially at the summits. The number of particles was 3.3 +/- 0.8/microns2 in the control, 3.6 +/- 0.8/microns2 at 0 hour, 14.4 +/- 0.9/microns2 at 3 hours, 25.4 +/- 1.4/microns2 at 12 hours, and 22.7 +/- 2.6/microns2 at 24 hours postinjection. ANOVA indicated that the time-course was an important factor (P < 0.01). Our results showed that ICAM-1 could be augmented in the corneal endothelium by endotoxin. The interrelationship between ICAM-1 expression and cytoplasmic processes seems to be important for the neutrophil-binding mechanism.
Assuntos
Endotélio Corneano/metabolismo , Endotoxinas/farmacologia , Molécula 1 de Adesão Intercelular/biossíntese , Soluções para Preservação de Órgãos , Salmonella typhimurium , Adenosina , Alopurinol , Animais , Endotélio Corneano/efeitos dos fármacos , Endotélio Corneano/ultraestrutura , Glutationa , Imuno-Histoquímica , Insulina , Molécula 1 de Adesão Intercelular/ultraestrutura , Microscopia Eletrônica de Varredura , Microscopia Imunoeletrônica , Rafinose , Ratos , Ratos Endogâmicos LewRESUMO
As persisting parts of the mesotendon, Vinculum breve and Vinculum longum are known to serve as transport and conduction pathways to the intravaginal segments of flexor tendons. For morphological evaluation of their constancy, they were dissected out of, measured, and histologically examined on the 2nd-5th fingers in 53 hands of donated cadavers. The Vincula brevia existed in all cases more or less in association with the insertion of the superficialis as well as profundus flexor tendon, meanwhile the Vincula longa varied in number from 0 to 3 per tendon from one finger to the others, even 4 in the case of the index superficialis tendon. Light microscopic investigation of vascular patency was carried out on semithin resin sections of 137 Vincula longa obtained from the flexor superficialis and profundus tendons of 53 index fingers. Up to 5 or more arterial and venous vessels were counted per Vinculum longum. The complete absence of a patent artery was recognized in 6 out of 62 Vincula longa of the flexor superficialis and in 22 out of 75 of the profundus flexor. Most frequently, the Vincula longa had a single artery and a single vein. Considering the constant presence of vessels on the cross section, the Vinculum breve is regarded as essential for maintaining the tendons at work. In contrast, the significance of Vinculum longum will be variable for the microcirculation of intravaginal segments of the flexor tendons individually and also in the course of aging.
Assuntos
Mãos , Tendões/irrigação sanguínea , Grau de Desobstrução Vascular , Adulto , Idoso , Idoso de 80 Anos ou mais , Artérias/fisiologia , Cadáver , Humanos , Microcirculação , Pessoa de Meia-Idade , Veias/fisiologiaRESUMO
After stimulation with Salmonella typhimurium endotoxin, the intercellular adhesion molecule-1 (ICAM-1) was studied on the corneal endothelium and associated leukocytes in rats using immunoscanning electron microscopy. Two hundred micrograms of the endotoxin was injected in Lewis rats. The corneae were excised at 0-h and 16-h-postinjection time (n = 5, respectively). The corneae were prepared in hypothermic University of Wisconsin (UW) solution for immunoscanning electron microscopy. Histotopographical examination visualized ICAM-1 antigen on cytoplasmic processes of the corneal endothelium, arranged along microfolds, especially at the peaks. In the leukocytes, ICAM-1 was located primarily in morphologically non-specialized domains of the cell body surface, and only rarely scattered on the surface of microvillar projections. We concluded that the endotoxin stimulation can increase ICAM-1 in both corneal endothelium and associated leukocytes. Increased ICAM-1 may be an important factor for the leukocytes to form clustering and adhering to the corneal endothelium.