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PubMed1994

Characteristics of the light-induced phase response of circadian activity rhythms in common marmosets, Callithrix j. jacchus [primates-Cebidae].

Phase-response experiments using 1-h light pulses (LPs) of 1,100 lux applied under constant dim light of 0.3 lux were conducted with common marmosets, Callithrix j. jacchus, in order to obtain a complete phase-response curve established according to the common experimental procedure in a diurnal primate. Maximal phase delays of the free-running circadian activity rhythm (-90 min) were induced by LPs delivered at circadian time (CT) 12; e.g., during the beginning of the marmosets' rest time, maximal advances (+25 min) were elicited by pulses administered during the late subjective night at CT 21. In contrast to rodents, neither regular transient cycles nor regular period responses resulted from LP applications at different phases. To check whether the underlying period length affects the phase response in primates as well, the marmosets' circadian timing system was entrained to 25 h by a light:dark (LD) cycle of 12.5:12.5 h. The 1-h LPs were delivered during the first circadian cycle produced under constant dim light after the entraining LD periods. Here, LPs applied at CT 21 led to phase advances exceeding those measured during the steady-state free run. At CT 12, minor or no phase delays could be elicited. These findings show that the phase-shifting effect of LPs on the circadian system of marmosets is similar to that observed in other diurnal mammals. Some of the results indicate that in this diurnal primate, LP-induced phase shifts may be mediated in part by a light-induced increase in locomotor activity (arousal).

Animals↗
PubMed1996

Cutaneous representations of the hand and other body parts in the cuneate nucleus of a primate, and some relationships to previously described cortical representations.

Dynamic properties of primate somatosensory maps are dependent on normal central adjacencies of cutaneous representations. The cuneate nucleus is an important brainstem processing center of cutaneous information. Surprisingly, there are no descriptions of functional representations of the skin in the primate cuneate nucleus; as a result, the relationships of functional representations at the brainstem level and other levels of the somatosensory neuraxis remain obscure. The present neurophysiological study indicates that the main cuneate nucleus of marmoset monkeys (Callithrix jacchus) contains organized representations of cutaneous inputs from the hand, forelimb, and adjacent body between the lateral face and proximal hindlimb. Inputs from the glabrous hand are represented continuously across transverse planes in the cuneate, whereas inputs from the hairy hand are represented discontinuously. Inputs from distal to proximal, and radial to ulnar, parts of the hand are mapped in an organized manner. At rostrocaudal levels where the cuneate nucleus is near its largest transverse area, the map of the hand is about 2600 times smaller than the hand skin area it represents. Cuneate representations of the forelimb and trunk are represented both medial and lateral to the hand representation, and interface with representations in the adjacent gracile and trigeminal nuclei. These findings provide a starting point for understanding functional representations of the skin in the cuneate nucleus of primates. Furthermore, they provide a basis for understanding relationships of cutaneous representations at different levels of the neuraxis. In this regard, comparisons of the present results to previously defined representations in the somatosensory (area 3b) cortex indicate that cuneate hand representations are several times smaller than cortical representations, and that there are similarities and differences in adjacencies of cuneate and cortical representations.

Animals↗
PubMed1989

Development of methodology for recording colonic myoelectrical activity in the infant primate.

In order to study developmental aspects of colonic motility, we have developed a miniaturized electrophysiologic recording system for use in the infant primate rhesus (Macaca mulatta). Technical considerations including absence of rectal valves, decreased tissue thickness and small colonic diameter limit application of standard non-surgical recording methodology in this model. In-vivo testing with 4 different bipolar electrode probe configurations yielded satisfactory quality recordings only with silver chloride suction electrodes. Using this system, colonic slow waves and spike action potentials were studied in 6 infant primates (ages 1 to 7 months) both fasting and following a standard liquid meal of 10 cc/kg. In response to feeding, colonic spike potentials increased from 7.8 +/- 1.7 to 14.2 +/- 4.1 within 15 minutes (mean spikes +/- SEM/5 min interval). The observed response of the distal colon to a meal in this model is similar to the response reported in adult humans using intraluminal recording techniques. Utilizing the described methodology, the infant primate appears to be a suitable model for investigation of developmental aspects of gastrointestinal motility and electrophysiology. These techniques have important direct applications for investigation in the human infant.

Animals↗
PubMed2002

Induction of glioblastoma multiforme in nonhuman primates after therapeutic doses of fractionated whole-brain radiation therapy.

OBJECT: To determine the acute and long-term effects of a therapeutic dose of brain radiation in a primate model, the authors studied the clinical, laboratory, neuroimaging, molecular, and histological outcomes in rhesus monkeys that had received fractionated whole-brain radiation therapy (WBRT). METHODS: Twelve 3-year-old male primates (Macaca mulatta) underwent fractionated WBRT (350 cGy for 5 days/week for 2 weeks, total dose 3500 cGy). Animals were followed clinically and with laboratory studies and serial magnetic resonance (MR) imaging. They were killed when they developed medical problems or neurological symptoms, lesions appeared on MR imaging, or at study completion. Gross, histological, and molecular analyses were then performed. Nine (82%) of 11 animals that underwent long-term follow up (> 2.5 years) developed neurological symptoms and/or enhancing lesions on MR imaging, which were defined as glioblastoma multiforme (GBM), 2.9 to 8.3 years after radiation therapy. The GBMs were categorized as either unifocal (three) or multifocal (six), and were located in the supratentorial (six), infratentorial (two), or both (one) cranial regions. Histological examination revealed distant, noncontiguous tumor invasion within the white matter of all nine animals harboring GBMs. Novel interspecies comparative genomic hybridization (three animals) uniformly showed deletions in the GBMs that corresponded to chromosome 9 in humans. CONCLUSIONS: The high rate of GBM formation (82%) following a therapeutic dose of WBRT in nonhuman primates indicates that radioinduction of these neoplasms as a late complication of this therapy may occur more frequently than is currently recognized in human patients. The development of these tumors while monitoring the monkeys' conditions with clinical and serial MR imaging studies, and access to the tumor and the entire brain for histological and molecular analyses offers an opportunity to gather unique insights into the nature and development of GBMs.

Animals↗
PubMed2006

Preclinical evaluation of the neuroprotective effect of soluble complement receptor type 1 in a nonhuman primate model of reperfused stroke.

OBJECT: Postischemic cerebral inflammatory injury has been extensively investigated in an effort to develop effective neuroprotective agents. The complement cascade has emerged as an important contributor to postischemic neuronal injury. Soluble complement receptor Type 1 (sCR1), a potent inhibitor of complement activation, has been shown to reduce infarct volume and improve functional outcome after murine stroke. Given numerous high-profile failures to translate promising antiinflammatory strategies from the laboratory to the clinic and given the known species-specificity of the complement cascade, the authors sought to evaluate the neuroprotective effect of sCR1 in a nonhuman primate model of stroke. METHODS: A total of 48 adult male baboons (Papio anubis) were randomly assigned to receive 15 mg/kg of sCR1 or vehicle. The animals were subjected to 75 minutes of middle cerebral artery occlusion/reperfusion. Perioperative blood samples were analyzed for total complement activity by using a CH50 assay. Infarct volume and neurological scores were assessed at the time the animals were killed, and immunohistochemistry was used to determine cerebral drug penetration and C1q deposition. An interim futility analysis led to termination of the trial after study of 12 animals. Total serum complement activity was significantly depressed in the sCR1-treated animals compared with the controls. Immunostaining also demonstrated sCR1 deposition in the ischemic hemispheres of treated animals. Despite these findings, there were no significant differences in infarct volume or neurological score between the sCR1--and vehicle-treated cohorts. CONCLUSIONS: A preischemic bolus infusion of sCR1, the most effective means of administration in mice, was not neuroprotective in a primate model. This study illustrates the utility of a translational primate model of stroke in the assessment of promising antiischemic agents prior to implementation of large-scale clinical trials.

Animals↗
PubMed2002

Peripheral nerve grafts promoting central nervous system regeneration after spinal cord injury in the primate.

OBJECT: Partial restoration of hindlimb function in adult rats following spinal cord injury (SCI) has been demonstrated using a variety of transplantation techniques. The purpose of the present study was twofold: 1) to determine whether strategies designed to promote regeneration in the rat can yield similar results in the primate; and 2) to establish whether central nervous system (CNS) regeneration will influence voluntary grasping and locomotor function in the nonhuman primate. METHODS: Ten cynomologus monkeys underwent T-11 laminectomy and resection of a 1-cm length of hemispinal cord. Five monkeys received six intercostal nerve autografts and fibrin glue containing acidic fibroblast growth factor (2.1 microg/ml) whereas controls underwent the identical laminectomy procedure but did not receive the nerve grafts. At 4 months postgrafting, the spinal cord-graft site was sectioned and immunostained for peripheral myelin proteins, biotinylated dextran amine, and tyrosine hydroxylase, whereas the midpoint of the graft was analyzed histologically for the total number of myelinated axons within and around the grafts. The animals underwent pre- and postoperative testing for changes in voluntary hindlimb grasping and gait. CONCLUSIONS: 1) A reproducible model of SCI in the primate was developed. 2) Spontaneous recovery of the ipsilateral hindlimb function occurred in both graft- and nongraft-treated monkeys over time without evidence of recovering the ability for voluntary tasks. 3) Regeneration of the CNS from proximal spinal axons into the peripheral nerve grafts was observed; however, the grafts did not promote regeneration beyond the lesion site. 4) The grafts significantly enhanced (p < 0.0001) the regeneration of myelinated axons into the region of the hemisected spinal cord compared with the nongrafted animals.

Animals↗
PubMed2004

Nonsusceptibility of primate cells to Taura syndrome virus.

Taura syndrome virus (TSV), a pathogen of penaeid shrimp and member of the family Dicistroviridae, was recently reported to have the ability to infect primate cells. We independently retested this hypothesis. Three lines of primate cells FRhK-4, MA-104, and BGMK, which are highly susceptible to infection by human picornaviruses, were challenged with TSV. Viral replication was assayed by real-time reverse transcription-polymerase chain reaction using cell media samples collected on days 0, 4, and 7 postchallenge. By day 7, genome copy numbers had decreased 25%-99%. No cytopathic effect was observed after 7 days. An in situ hybridization assay, with gene probes specific for detection of TSV, was negative for TSV in challenged cells. The infectivity of residual virus in the cell culture media at day 7 was confirmed by bioassay using TSV-free indicator shrimp (Litopenaeus vannamei). TSV did not infect the primate cells tested, and no evidence of zoonotic potential was found.

Animals↗
PubMed2003

A simple and cost-effective method for the isolation of islets from nonhuman primates.

Recent advances in islet cell transplantation have led to insulin independence in a majority of islet transplant recipients. However, there exists a need to overcome the shortage of donor tissue and the necessity for life-long immunosuppression. Preclinical studies in large animal models are necessary to evaluate the safety and efficacy of alternative approaches for clinical islet transplantation. The nonhuman primate serves as an appropriate animal model for such investigations; however, a major impediment in performing such preclinical research has been the difficulty in isolating islets of sufficient quantity and quality. The current study describes a simple and cost-effective method to isolate nonhuman primate islets to support preclinical islet transplantation research. The results of islet isolations from 54 cynomolgus monkeys and 4 baboons are reported. The pancreas was infused with Liberase HI and subjected to static digestion. The digested tissue was shaken, filtered through a mesh screen, applied to a discontinuous gradient, and centrifuged in much the same manner as with conventional rodent islet isolations. Islets were collected from the two interfaces, washed, and transplanted. Following purification, cynomolgus monkey islet isolation yields were 50,100 +/- 3120 IE total or 8760 +/- 420 IE/g pancreas with the percent purity and viability of 90.8 +/- 0.9 and 90.7 +/- 0.7, respectively. Total insulin content of the isolated islets was 405 +/- 53 microg insulin with DNA content being and 976 +/- 117 microg DNA, corresponding to a ratio of 0.57 microg insulin/microg DNA. STZ-induced diabetes was reversed in both mouse and nonhuman primate recipients, which possessed significant levels of c-peptide following transplantation and well-granulated islet grafts. The technique yields sufficient numbers of pure and viable islets to support preclinical research to develop improved strategies to prevent the immune destruction of the transplanted islet graft.

Animals↗
PubMed2003

Strong cytosine-guanosine-independent immunostimulation in humans and other primates by synthetic oligodeoxynucleotides with PyNTTTTGT motifs.

Synthetic oligodeoxynucleotides (ODNs) containing cytosine-guanosine (CpG) motifs stimulate B and plasmacytoid dendritic cells of the vertebrate immune system. We found that in primates strong stimulation of these cells could also be achieved using certain non-CpG ODNs. The immunostimulatory motif in this case is a sequence with the general formula PyNTTTTGT in which Py is C or T, and N is A, T, C, or G. Assays performed on purified cells indicated that the immunostimulatory activity is direct. The use of a nuclease-resistant phosphorothioate backbone is not a necessary condition, since phosphodiester PyNTTTTGT ODNs are active. It was also demonstrated that ODN 2006, a widely used immunostimulant of human B cells, possess two kinds of immunostimulatory motifs: one of them mainly composed of two successive TCG trinucleotides located at the 5' end and another one (duplicated) of the PyNTTTTGT kind here described. Even though PyNTTTTGT ODNs are mainly active on primate cells, some of them, bearing the CATTTTGT motif, have a small effect on cells from other mammals. This suggests that the immunostimulatory mechanism activated by these ODNs was present before, but optimized during, evolution of primates. Significant differences in the frequency of PyNTTTTGT sequences between bacterial and human DNA were not found. Thus, the possibility that PyNTTTTGT ODNs represent a class of pathogen-associated molecular pattern is unlikely. They could, more reasonably, be included within the category of danger signals of cell injury.

Adjuvants, Immunologic↗
PubMed1999

Model for the fetal recruitment of simian gamma-globin genes based on findings from two New World monkeys Cebus apella and Callithrix jacchus (Platyrrhini, Primates).

The originally embryonic gamma-globin locus duplicated and acquired a novel (fetal) pattern of expression in a defined time period (55-40 million years ago) during primate phylogeny. The objective of this study was to determine some of the factors that led to first the emergence of fetal gamma specificity and then the maintenance of different fetal gamma expression patterns in extant simian primates (e.g., human, capuchin monkey). Analyses focused on two platyrrhine (New World monkey) species: the common marmoset (Callithrix jacchus) and the brown capuchin monkey (Cebus apella), each of which has paired, non-allelic gamma loci (5'-gamma 1-gamma 2-3'). Quantitation of beta-type globin mRNAs expressed in a 4.5 week old embryo of Callithrix jacchus revealed that in addition to its primary epsilon-globin message, considerable amounts of gamma 1 message and just trace levels of gamma 2 message are present. In contrast, analyses of gamma-globin messenger RNAs expressed in a Cebus apella fetal liver indicated that gamma 2 expression is at least 120 times greater than gamma 1 expression. Using a luciferase reporter and a transient assay system, the strengths of gamma 1 and gamma 2 promoter fragments of Cebus apella were compared in erythroid (K562) and non-erythroid (HeLa) cell lines. Due to the lack of chromatin repression in a transient expression system, the results do not fully recapitulate globin expression. However, the results suggest that sequences contained within the Cebus gamma 1 and gamma 2 proximal promoter regions (-200 to +1 bp) can direct gamma transcription in both cell lines. In K562 and, to a lesser extent, in HeLa cells Cebus gamma 2 promoter fragments were significantly stronger (P < 0.01) than gamma 1 promoter fragments. This is consistent with the fact that the Cebus gamma 1 promoter contains several mutations, including a proximal CCAAT box mutation (CCAAT-->CCAAc). The epsilon-gamma 1 intergenic distances in these platyrrhines (5.4 kb in Cebus apella and 6.9 kb in Callithrix jacchus) are short, supporting the inference that it was also short in the stem simian primates. The results suggest that immediately following the gamma duplication, the gamma 1 gene of the stem simians was still embryonic and the downstream gamma 2 gene was largely silent. A further inference is that once gamma 2 accumulated regulatory mutations that disrupted binding of fetal repressors, gamma 2 was expressed fetally and, through gene conversion, passed these characteristics to the gamma 1 gene. The fetal expression of gamma 1 is most evident in catarrhines (Old World monkeys and hominoids), which preferentially express the gamma 1 locus during fetal life.

Animals↗
PubMed1999

Autoradiographic and in situ hybridization localization of corticotropin-releasing factor 1 and 2 receptors in nonhuman primate brain.

Two different corticotropin-releasing factor (CRF) receptors, CRF1 and CRF2, have been identified in rat and human brain. Although the two receptor subtypes show a markedly different distribution in the rat brain, their distribution in the primate brain has not been described previously. In this study, the neuroanatomic distribution of CRF1 and CRF2 receptor binding sites in rhesus monkey (Macaca mulatta) was assessed by using iodine 125 ([125I)-Tyr0]-sauvagine with or without the selective CRF1 receptor antagonist CP-154,526-1. Radiolabeled human cRNA probes were used to map the distribution of the two receptor mRNAs with in situ hybridization. Both CRF1 and CRF2 receptors were found in the pituitary and throughout the neocortex (especially, in prefrontal, cingulate, striate, and insular cortices), amygdala, and hippocampal formation of the monkey brain. This is in contrast to the distribution of these receptors reported in the rat brain, in which generally only the CRF1 receptor is found in the pituitary and neocortex. These results suggest that, in primates, both CRF1 and CRF2 receptors may be involved in mediating the effects of CRF on cognition, behavior, and pituitary-adrenal function. The presence of CRF1 (but not CRF2) receptors within the locus coeruleus, cerebellar cortex, nucleus of the solitary tract, thalamus, and striatum and of CRF2 (but not CRF1) receptors in the choroid plexus, certain hypothalamic nuclei, the nucleus prepositus, and the nucleus of the stria terminalis suggests that each receptor subtype also may have distinct functional roles within the primate central nervous system.

Amphibian Proteins↗
PubMed1999

Posterolateral intertransverse process spinal arthrodesis with rhBMP-2 in a nonhuman primate: important lessons learned regarding dose, carrier, and safety.

Recombinant osteoinductive proteins have been used successfully in canine and rabbit models of posterolateral intertransverse process arthrodesis, but little is known about the ability of these compounds to achieve fusion in nonhuman primates. The goals of this investigation were to compare different combinations of recombinant human bone morphogenetic protein-2 (rhBMP-2) dosages and carriers in a nonhuman primate model of posterolateral intertransverse process spinal fusion and to determine the feasibility of using rhBMP-2 in the presence of exposed dura in a laminectomy model. Posterolateral intertransverse process arthrodeses were performed at L4-5 in 29 rhesus monkeys. The most striking findings were as follows: rhBMP-2 could induce bone in a nonhuman primate spine; the presence of a laminectomy defect with exposed dura did not preclude the safe use of rhBMP-2 for posterolateral fusion; soft tissue compression of the collagen sponge carrier prevented bone induction at standard BMP doses, presumably due to squeezing of the protein out of the sponge; and longer rhBMP-2 loading time into the collagen carrier and mechanical protection from the soft tissue compression both allowed more bone induction at a lower dose of rhBMP-2.

Animals↗
PubMed1999

Primate herpesviral oncogenes.

Gammaherpesviruses are the most rapidly growing members of the herpesviridae family. Gamma herpesviruses share similarity in their genome organizations and in early and late lytic genes that are required for viral replication. A distinct characteristic of gamma herpesviruses is their ability to establish latent infection in lymphoid cells, and some of these viruses are closely associated with abnormal proliferation and cancer in primates. The first open reading frame of the primate gamma herpesviruses has been shown to directly contribute to virus-associated pathogenesis. This open reading frame encodes latent membrane protein-1 (LMP1) in Epstein-Barr virus, Saimiri transformation protein (STP) in Herpesvirus Saimiri, K1 in Kaposi's sarcoma-associated herpesvirus, and R1 in Rhesus monkey Rhadinovirus. All of these gene products are capable of eliciting cellular signal transduction events, resulting in cell growth transformation. This review briefly summarizes the current view on the transforming mechanisms utilized by primate herpesviral oncogenes.

Animals↗
PubMed1999

Protection against hyperacute xenograft rejection of transgenic rat hearts expressing human decay accelerating factor (DAF) transplanted into primates.

BACKGROUND: Production of transgenic pigs for multiple transgenes is part of a potential strategy to prevent immunological events involved in xenograft rejection. Use of a genetically engineerable rodent as a donor in primates could allow testing in vivo of the effects of different transgenes on controlling xenograft rejection. As a first step in the development of a donor containing multiple transgenes, transgenic rats for human decay-accelerating factor (DAF) were used as heart donors to test their resistance against complement (C)-mediated rejection by non-human primates. MATERIALS AND METHODS: Transgenic rats were generated by using a construct containing the human DAF cDNA under the transcriptional control of the endothelial cell (EC)-specific human ICAM-2 promoter. DAF expression was evaluated by immunohistology and by FACS analysis of purified ECs. Resistance of transgenic hearts against C-mediated damage was evaluated by ex vivo perfusion with human serum and by transplantation into cynomolgus monkeys. RESULTS: Immunohistological analysis of DAF expression in several organs from two transgenic lines showed uniform expression on the endothelium of all blood vessels. ECs purified from transgenic hearts showed 50% DAF expression compared to human ECs and >70% reduction of C-dependent cell lysis compared to control rat ECs. Hemizygous transgenic hearts perfused with human serum showed normal function for >60 min vs. 11. 2 +/- 1.7 min in controls. Hemi- or homozygous transgenic hearts transplanted into cynomolgus monkeys showed longer survival (15.2 +/- 7 min and >4.5 hr, respectively) than controls (5.5 +/- 1.4 min). In contrast to hyperacutely rejected control hearts, rejected homozygous DAF hearts showed signs of acute vascular rejection (AVR) characterized by edema, hemorrhage, and an intense PMN infiltration. CONCLUSIONS: We demonstrate that endothelial-specific DAF expression increased heart transplant survival in a rat-to-primate model of xenotransplantation. This will aid in the analysis of AVR and of new genes that may inhibit this form of rejection, thus helping to define strategies for the production of transgenic pigs.

Animals↗
PubMed2000

Pharmacokinetics of argatroban in primates: evidence on endogenous uptake.

BACKGROUND: Antithrombin agent, argatroban, is currently undergoing several clinical trials for cardiovascular indications. Because of its solubility, this drug is usually administered via an intravenous bolus followed by infusion. The purpose of this study was to determine the pharmacokinetics of argatroban after intravenous bolus injection in primates. METHODS: Parallel in vitro studies in primate whole blood were carried out to simulate a one-compartment system. Argatroban (range 1.0-7.5 mg/kg) was administered to four groups of primates and blood samples were drawn at various time periods. Argatroban measurements were made in plasma using functional (aPTT, Heptest, TT) and HPLC methods. RESULTS: In vitro, argatroban primarily distributed in the plasma in proportionate amounts. Relative uptake of argatroban to the blood cells (leukocytes and erythrocytes) was minimum. However, in vivo, argatroban followed a complex pharmacokinetics. Within 5 min after the bolus administration, only <20% of argatroban was recovered. The recovered amount was proportionate to the dosage and followed the expected kinetics with a half-life of <20 min. Simultaneous quantitation of M1-metabolite of argatroban revealed only a fraction of recovered argatroban (approximately 25%) converted into M1 in these experimental settings. Results obtained from the functional and absolute methods correlated well. HPLC profile did not reveal the presence of any other metabolite(s). CONCLUSIONS: These observations suggest that argatroban may be endogenously taken up by the vascular or other sites and may exhibit a complex kinetics. In acute settings, the metabolic transformation of argatroban to M1 is relatively low. To further clarify the pharmacokinetics/pharmacodynamics of this drug, additional studies are warranted.

Animals↗
PubMed2000

Histopathological characterization of nephritides in the brown capuchin monkey, Cebus apella (Primates: Cebidae).

The renal lesions are of special importance in the captive primates. The most commonly pathologies are: pyelonephritis, nephrocalcinosis, glomerulonephritis, congenital malformations, hydronephrosis and functional diseases. We report the histopathological study of renal lesions of five cases of deaths in Cebus apella (Primates) of the Argentinean Primate Center. The ages of the monkeys were from 4 months to 15 years old. Microscopically, we have observed principally acute diffuse proliferative glomerulonephritis, hilar mesangio proliferative glomerulonephritis, extracapilar glomerulonephritis with crescents, chronic interstitial nephritis and chronic pyelophritis.

Animals↗
PubMed2000

Clusterin protein diversity in the primate eye.

PURPOSE: The clusterin gene encodes a multi-functional protein that has been identified in different tissues, including a number of different eye tissues, primarily in the mouse and to a much lesser extent in humans. Clusterin has been implicated in a number of cellular processes such as lipid transport, membrane integrity, apoptosis, and neurodegeneration, all of which could be important to the biology of the eye. In the current communication, we provide data that confirms the expression of clusterin in a number of different human eye tissues and establishes the expression profile of this gene in monkey derived eye tissues. The issue that we sought to examine is whether a broad profile of clusterin expression in the eye is consistent in primates (monkey and human). METHODS: The majority of our study was done using monkey eye tissues. Where possible, we have used human tissues in order to confirm published findings. Northern and western analysis was performed using tissues derived from monkey eyes. In situ hybridization and immunochemistry were carried out on human eye sections. RESULTS: Clusterin mRNA is expressed in primate lens, cornea, limbus, sclera, orbital muscle, ciliary body, retina, RPE/choroid, and RPE cells in culture. Western analysis revealed that two major groups of clusterin exist in the eye, a high molecular weight group (>100 kDa) and a second group consisting of at least five clusterin species that are all approximately 80 kDa. Analysis of conditioned media from RPE cells cultured on permeable supports suggests that different forms of clusterin display alternative patterns of secretion. CONCLUSIONS: Clusterin is expressed in a broad range of eye tissues in both human and monkey, suggesting that this is a characteristic feature in primates. We demonstrate for the first time that a diverse number of clusterin isoforms were observed in monkey eye tissues by western analysis. Meanwhile, the molecular size of clusterin mRNA detected in the array of tissues are identical in size, suggesting that the nature of the diversity in clusterin forms is due to post-translational modifications. In addition, new insights were made in defining clusterin expression in ciliary body, cornea, and the retinal pigment epithelium.

Animals↗
PubMed1979

Cholic acid accumulation by the ciliary body and by the iris of the primate eye.

Cholic acid accumulates in both the ciliary body and the iris of the primate eye during in vitro incubations at 37 degrees C for 1 hr. Incubation at 0 degrees C depresses uptake in both tissues. The washout of preaccumulated cholic acid occurs some 3.4 times faster from the iris than from the ciliary body. The mechanism of cholic acid accumulation in both tissues is less sensitive to inhibition by high iodipamide concentrations and also is less sensitive to inhibition by high hippurate concentrations than the mechanism of p-aminohippurate (PAH) accumulation. Therefore, although overlap may exist, the cholic acid--uptake mechanism differs from the PAH-uptake mechanism in both the primate ciliary body and the primate iris.

Animals↗