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Jnawali A, Puri S, Frishman LJ, Ostrin LA. Visual function in guinea pigs: behavior and electrophysiology. Clin Exp Optom 2021; 104:523-531. [PMID: 33689637 DOI: 10.1080/08164622.2021.1878827] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
Abstract
CLINICAL RELEVANCE Guinea pig visual function is characterised based on behavioural and electrophysiological measures and retinal ganglion cell density is examined to further develop the guinea pig as a model of human ocular conditions. BACKGROUND Guinea pigs are an important model of human ocular conditions. Here, guinea pig spatial frequency discrimination, pattern and full-field photopic electroretinography (ERG), and retinal ganglion cell distribution were investigated. METHODS Adult guinea pigs (n = 6) were included. Optomotor responses to square-wave gratings from 0.3 to 2.4 cycles per degree (cpd) were assessed. Pattern ERG responses were recorded using square-wave gratings from 0.025 to 0.25 cpd at 100% contrast, alternating at a temporal frequency of 1.05 Hz. Full-field ERG responses were recorded using a 10.0 cd.s/m2 flash. Ganglion cell density was determined histologically from retinal whole mounts. RESULTS Maximum spatial frequency discrimination was 1.65 ± 0.49 cpd for stimuli rotating temporally to nasally and 0.75 ± 0.16 cpd for stimuli rotating nasally to temporally. For pattern ERG, a maximum amplitude of 3.50 ± 1.16 µV for the first negative to positive peak (N1P1) was elicited with a 0.025 cpd grating, and 2.5 ± 0.1 µV for the positive to second negative peak (P1N2) was elicited with a 0.05 cpd grating. For full-field ERG, a-wave amplitude was 19.2 ± 4.24 µV, b-wave amplitude was 33.6 ± 8.22 µV, and the PhNR was 24.0 ± 5.72 µV. Peak retinal ganglion cell density was 1621 ± 129 cells/mm2, located 1-2 mm superior to the optic nerve head. CONCLUSION Guinea pigs show directional selectivity for stimuli moving in the temporal to the nasal visual field. Guinea pigs demonstrate a quantifiable PhNR in the full-field ERG and negative and positive waveforms in the pattern ERG. The visual streak is located in the superior retina.
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Affiliation(s)
| | - Sudan Puri
- College of Optometry, University of Houston, Houston, TX, USA
| | | | - Lisa A Ostrin
- College of Optometry, University of Houston, Houston, TX, USA
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Ostrin LA, Wildsoet CF. Optic nerve head and intraocular pressure in the guinea pig eye. Exp Eye Res 2015; 146:7-16. [PMID: 26698659 DOI: 10.1016/j.exer.2015.12.007] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2015] [Revised: 11/02/2015] [Accepted: 12/11/2015] [Indexed: 10/22/2022]
Abstract
The guinea pig is becoming an increasingly popular model for studying human myopia, which carries an increased risk of glaucoma. As a step towards understanding this association, this study sought to characterize the normal, developmental intraocular pressure (IOP) profiles, as well as the anatomy of the optic nerve head (ONH) and adjacent sclera of young guinea pigs. IOP was tracked in pigmented guinea pigs up to 3 months of age. One guinea pig was imaged in vivo with OCT and one with a fundus camera. The eyes of pigmented and albino guinea pigs (ages 2 months) were enucleated and sections from the posterior segment, including the ONH and surrounding sclera, processed for histological analyses - either hematoxylin and eosin (H&E) staining of paraffin embedded, sectioned tissue (n = 1), or cryostat sectioned tissue, processed for immunohistochemistry (n = 3), using primary antibodies against collagen types I-V, elastin, fibronectin and glial fibrillary acidic protein (GFAP). Transmission and scanning electron microscopy (TEM, SEM) studies of ONHs were also undertaken (n = 2 & 5 respectively). Mean IOPs ranged from 17.33 to 22.7 mmHg, increasing slightly across the age range studied, and the IOPs of individual animals also exhibited diurnal variations, peaking in the early morning (mean of 25.8, mmHg, ∼9 am), and decreasing across the day. H&E-stained sections showed retinal ganglion cell axons organized into fascicles in the prelaminar and laminar region of the ONHs, with immunostained sections revealing collagen types I, III, IV and V, as well as elastin, GFAP and fibronectin in the ONHs. SEM revealed a well-defined lamina cribrosa (LC), with radially-oriented collagen beams. TEM revealed collagen fibrils surrounding non-myelinated nerve fiber bundles in the LC region, with myelination and decreased collagen posterior to the LC. The adjacent sclera comprised mainly crimped collagen fibers in a crisscross arrangement. Both the sclera and LC were qualitatively similar in structure in pigmented and albino guinea pigs. The well-organized, collagen-based LC of the guinea pig ONH is similar to that described for tree shrews and more similar to the human LC than that of other rodents that lack collagen. Based on these latter structural similarities the guinea pig would seem a promising model for investigating the relationship between myopia and glaucoma.
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Affiliation(s)
- Lisa A Ostrin
- College of Optometry University of Houston, 4901 Calhoun, Houston, TX 77004, USA.
| | - Christine F Wildsoet
- School of Optometry University of California Berkeley, 588 Minor Hall, Berkeley, CA 94720, USA.
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Abdel-Hamid NM, El-Moselhy MA, El-Baz A. Hepatocyte Lysosomal Membrane Stabilization by Olive Leaves against Chemically Induced Hepatocellular Neoplasia in Rats. Int J Hepatol 2011; 2011:736581. [PMID: 21994869 PMCID: PMC3170841 DOI: 10.4061/2011/736581] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/01/2010] [Revised: 09/29/2010] [Accepted: 10/17/2010] [Indexed: 01/27/2023] Open
Abstract
Extensive efforts are exerted looking for safe and effective chemotherapy for hepatocellular carcinoma (HCC). Specific and sensitive early biomarkers for HCC still in query. Present work to study proteolytic activity and lysosomal membrane integrity by hepatocarcinogen, trichloroacetic acid (TCA), in Wistar rats against aqueous olive leaf extract (AOLE).TCA showed neoplastic changes as oval- or irregular-shaped hepatocytes and transformed, vesiculated, and binucleated liver cells. The nuclei were pleomorphic and hyperchromatic. These changes were considerably reduced by AOLE. The results added, probably for the first time, that TCA-induced HCC through disruption of hepatocellular proteolytic enzymes as upregulation of papain, free cathepsin-D and nonsignificant destabilization of lysosomal membrane integrity, a prerequisite for cancer invasion and metastasis. AOLE introduced a promising therapeutic value in liver cancer, mostly through elevating lysosomal membrane integrity. The study substantiated four main points: (1) the usefulness of proteolysis and lysosomalmembrane integrity in early prediction of HCC. (2) TCA carcinogenesis is possibly mediated by lysosomal membrane destabilization, through cathepsin-D disruption, which could be reversed by AOLE administration. (3) A new strategy for management of HCC, using dietary olive leaf system may be a helpful phytotherapeutic trend. (4) A prospective study on serum proteolytic enzyme activity may introduce novel diagnostic tools.
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Affiliation(s)
- N. M. Abdel-Hamid
- Department of Biochemistry, College of Pharmacy, Minia University, Minia, Egypt,*N. M. Abdel-Hamid:
| | - M. A. El-Moselhy
- Department of Pharmacology, College of Pharmacy, Minia University, Minia, Egypt
| | - A. El-Baz
- Department of Medical Biochemistry, College of Medicine, Mansura University, Mansura, Egypt
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Plasticity between neuronal pairs in layer 4 of visual cortex varies with synapse state. J Neurosci 2009; 29:15286-98. [PMID: 19955381 DOI: 10.1523/jneurosci.2980-09.2009] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
In neocortex, the induction and expression of long-term potentiation (LTP) and long-term depression (LTD) vary depending on cortical area and laminae of presynaptic and postsynaptic neurons. Layer 4 (L4) is the initial site of sensory afference in barrel cortex and primary visual cortex (V1) in which excitatory inputs from thalamus, L6, and neighboring L4 cells are integrated. However, little is known about plasticity within L4. We studied plasticity at excitatory synaptic connections between pairs and triplets of interconnected L4 neurons in guinea pig V1 using a fixed delay pairing protocol. Plasticity outcomes were heterogeneous, with some connections undergoing LTP (n = 7 of 42), some LTD (n = 19 of 42), and some not changing (n = 16 of 42). Although quantal analysis revealed both presynaptic and postsynaptic plasticity expression components, reduction in quantal size (a postsynaptic property) contributing to LTD was ubiquitous, whereas in some cell pairs, this change was overridden by an increase in the probability of neurotransmitter release (a presynaptic property) resulting in LTP. These changes depended on the initial reliability of the connections: highly reliable connections depressed with contributions from presynaptic and postsynaptic effects, and unreliable connections potentiated as a result of the predominance of presynaptic enhancement. Interestingly, very strong, reliable pairs of connected cells showed little plasticity. Pairs of connected cells with a common presynaptic or postsynaptic L4 cell behaved independently, undergoing plasticity of different or opposite signs. Release probability of a connection with initial 100% failure rate was enhanced after pairing, potentially avoiding silencing of the presynaptic terminal and maintaining L4-L4 synapses in a broader dynamic range.
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Li DK, Lin H, Kim SM. Effect of rainbow trout (Oncorhynchus mykiss) plasma protein on the gelation of Alaska pollock (Theragra chalcogramma) Surimi. J Food Sci 2008; 73:C227-34. [PMID: 18460115 DOI: 10.1111/j.1750-3841.2008.00712.x] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The effect of rainbow trout plasma protein (RPP) on the gelation of Alaska pollock surimi was determined to evaluate the possibility of its commercialization as a new protein additive. For modori gel, the breaking force, deformation, whiteness, and water holding capacity increased as the addition amount of RPP (0 to 0.75 mg/g) increased, and decreased at higher concentration of RPP (0.75 to 1.50 mg/g) (P < 0.05). Protein solubility of modori gel in the mixture of SDS, urea, and beta-mercaptoethanol decreased as the addition amount of RPP increased up to 0.75 mg/g, and increased at higher concentration of RPP (0.75 to 1.50 mg/g) (P < 0.05). The contents of trichloroacetic acid-soluble peptide decreased as the addition amount of RPP (0 to 1.50 mg/g) increased (P < 0.05). Based on the result of sodium dodecyl sulfate (SDS)-polyacrylamide gel electrophoresis (PAGE), most myosin heavy chain of surimi was not degraded when RPP was added. Thus, RPP was supposed to act as a protease inhibitor in the gelation of Alaska pollock surimi. An RPP of 0.75 mg/g was the optimal concentration to prevent the gel weakening of Alaska pollock surimi. Compounds with molecular weights less than 10 kDa in RPP had no significant effect on the gelation of Alaska pollock surimi based on the result of the dialyzed RPP.
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Affiliation(s)
- D K Li
- College of Food Science and Engineering, Ocean Univ. of China, Qingdao 266003, China
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Racine J, Behn D, Lachapelle P. Structural and functional maturation of the retina of the albino Hartley guinea pig. Doc Ophthalmol 2007; 117:13-26. [PMID: 18034273 DOI: 10.1007/s10633-007-9098-1] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2007] [Accepted: 10/29/2007] [Indexed: 10/22/2022]
Abstract
PURPOSE Altricial animals, such as rats and mice, are born with their eyes closed, compared to precocial animals, such as guinea pigs and humans, which have their eyes opened at birth. The purpose of this study was to investigate if the retina of guinea pigs (precocial animal) is subjected to a postnatal maturation process similar to that previously reported for rodents. METHODS Photopic and scotopic electroretinograms (ERG) and retinal histology were obtained from albino guinea pigs aged P1 to P75. RESULTS Photopic ERG responses reached maximal amplitudes at P5 (a-and b-waves), that is 5 days (b-wave) to 10 days (a-wave) earlier than scotopic responses. However, the postnatal gain in b-wave amplitude was significantly (P < 0.05) more important for the cone (73.38 +/- 4.4%) signal than for the rod (15.23 +/- 3.96%), suggesting that the rod function is more mature at birth. Similarly, the short latency photopic oscillatory potential (ie: OP2) reached its maximal value 5 days (P10) earlier than its scotopic equivalent (P15), while the long latency OPs (ie: OP3, OP4), reached their maximal values nearly 20 days sooner in scotopic condition. Finally retinal histology revealed a thinning of the retina with age, the latter being most pronounced at the level of the ganglion cell layer (GCL). CONCLUSION Our results thus confirm that despite its relative maturity at birth (compared to rodents), the retina of newborn albino guinea pigs undergoes significant postnatal maturation modifying its structure as well as its function, albeit not as extensive as that previously documented for altricial animals.
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Affiliation(s)
- Julie Racine
- Department of Neurology-Neurosurgery, McGill University-Montreal Children's Hospital-Research Institute, Montreal, QC, Canada
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Delbarre-Ladrat C, Chéret R, Taylor R, Verrez-Bagnis V. Trends in Postmortem Aging in Fish: Understanding of Proteolysis and Disorganization of the Myofibrillar Structure. Crit Rev Food Sci Nutr 2006; 46:409-21. [PMID: 16891212 DOI: 10.1080/10408390591000929] [Citation(s) in RCA: 165] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Postmortem tenderization is caused by enzymatic degradation of key structural proteins in myofibrils as well as in extracellular matrix, and of proteins involved in intermyofibrillar linkages and linkages between myofibrils and the sarcolemma. The function of these proteins is to maintain the structural integrity of myofibrils. Current data indicate that calpains and cathepsins may be responsible for degradation of these proteins. Other phenomena occurring in cells postmortem (pH drop, sarcoplasmic Ca2+ increase, osmotic pressure rise, oxidative processes) may act in synergy with proteases. Our understanding of the underlying mechanisms of muscle degradation should be improved for an accurate evaluation of the postmortem muscle changes and consequently of the fish quality.
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Loeliger M, Rees S. Immunocytochemical development of the guinea pig retina. Exp Eye Res 2005; 80:9-21. [PMID: 15652521 DOI: 10.1016/j.exer.2004.08.003] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2004] [Accepted: 08/03/2004] [Indexed: 10/26/2022]
Abstract
The aim of the present study was to establish the neurochemical profile of amacrine and horizontal cells during ontogeny in the guinea pig, a precocial species where significant retinal development occurs prenatally as opposed to altricial species where development largely occurs postnatally. The expression of neurochemical markers of horizontal cells and specific amacrine cell populations was investigated from 20 days of gestation (dg, term approximately 67 dg) to adulthood. Amacrine cell populations were identified immunohistochemically using antibodies to gamma-amino-butyric acid, cholineacetyltransferase, calbindin, calretinin, neuronal nitric oxide synthetase and tyrosine hydroxylase; horizontal cells were labelled with calbindin. All markers were present at 30 dg and had attained their mature (adult) laminar distribution and expression by 60 dg. Horizontal cells appeared in their final location at 30 dg with amacrine cell populations appearing in their final locations by 45 dg. Thus, in the guinea pig retina, the amacrine and horizontal cell populations investigated in this study are fully mature prior to birth.
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Affiliation(s)
- Michelle Loeliger
- Department of Anatomy and Cell Biology, University of Melbourne, Grattan St, Melbourne, Vic. 3010, Australia.
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Tremblay F, Abdel-Majid R, Neumann PE. Electroretinographic oscillatory potentials are reduced in adenylyl cyclase type I deficient mice. Vision Res 2002; 42:1715-25. [PMID: 12127105 DOI: 10.1016/s0042-6989(02)00113-x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Electroretinography (ERG) of adult Adcy1(brl) mutant mice, which are deficient in adenylyl cyclase type 1 (AC1) activity, revealed decreased amplitude of the oscillatory potentials (OP) and of the primary rising phase of the b-wave intensity-response function in scotopic conditions. These abnormalities were less discernable in 3-6 week old mutants. No abnormalities were detected in the ERG signal obtained in photopic conditions or in the dark adaptation dynamics. The mutants displayed no histologic evidence of retinal degeneration. Retinal output, as measured by visual evoked potentials, was not different from heterozygous control mice. AC1-dependent pathways contribute to the generation of the retinal response to light. They may be necessary for the maintenance of the neural generators of the ERG OP.
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Affiliation(s)
- François Tremblay
- Department of Ophthalmology, Dalhousie University, Halifax, NS, Canada B3H 4H7.
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Armitage JA, Bui BV, Gibson R, Vingrys AJ. Postnatal development of flicker sensitivity in guinea pigs. Clin Exp Optom 2001; 84:270-275. [PMID: 12366368 DOI: 10.1111/j.1444-0938.2001.tb05037.x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/21/2001] [Indexed: 11/28/2022] Open
Abstract
BACKGROUND: The retinal response to flickering stimuli (steady state ERG) recruits many retinal elements and is a sensitive indicator of early retinal dysfunction. This study reports the post-natal maturation of the steady state ERG response in guinea pigs. METHODS: The steady state ERG response to flickering stimuli (0.6 to 20 Hz) was recorded from dark adapted (more than 12 hrs) English Shorthair guinea pigs (n = 7) using flashes that produced rod and cone dominated responses. Temporal sensitivity functions and critical fusion frequencies (CFF) were derived over a range of ages from postnatal day (PND) 1 to 45. RESULTS: Guinea pig rod and cone temporal sensitivity functions show shape characteristics and CFF similar to humans. Furthermore, the post-natal development of the guinea pig temporal characteristics is also similar to that of humans - they are present at birth and mature rapidly post-natally. The time-course of CFF maturation is similar for rod and cone mediated responses. CONCLUSIONS: These data show that the temporal response and its maturation in the guinea pig retina is similar to that in humans. Therefore, we propose that the guinea pig is a particularly useful animal model to study retinal disease in early childhood.
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Affiliation(s)
- James A Armitage
- Department of Optometry and Vision Sciences, The University of Melbourne, 374 Cardigan St, Carlton, VIC, 3053, Australia
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Abstract
An important role for docosahexaenoic acid (DHA) within the retina is suggested by its high levels and active conservation in this tissue. Animals raised on n-3-deficient diets have large reductions in retinal DHA levels that are associated with altered retinal function as assessed by the electroretinogram (ERG). Despite two decades of research in this field, little is known about the mechanisms underlying altered retinal function in n-3-deficient animals. The focus of this review is on recent research that has sought to elucidate the role of DHA in retinal function, particularly within the rod photoreceptor outer segments where DHA is found at its highest concentration. An overview is also given of human infant studies that have examined whether a neonatal dietary supply of DHA is required for the normal development of retinal function.
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Affiliation(s)
- B G Jeffrey
- Department of Paediatrics and Child Health, Flinders Medical Centre, The Flinders University of South Australia, Bedford Park, Adelaide, South Australia 5042, Australia
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Bui BV, Vingrys AJ. Development of receptoral responses in pigmented and albino guinea-pigs (Cavia porcellus). Doc Ophthalmol 2001; 99:151-70. [PMID: 11097119 DOI: 10.1023/a:1002721315955] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
We describe the postnatal development of the electroretinogram (ERG) receptoral response in the guinea pig. In addition, the time course and nature of maturation was compared between albino and pigmented strains to consider the role that melanogenesis might have in this process. Electroretinograms were collected on groups of albino and pigmented animals from postnatal day (PD) PD1 to PD60. A-wave amplitudes and implicit times were extracted from filtered data (0-75 Hz). Receptoral components were modelled using the delayed gaussian model of Hood and Birch [1] fitted as an ensemble to the raw data. Guinea pigs show saturated amplitudes (RmP3) that are 50% of adult values at birth, these mature by PD12. Receptoral delay (t(d)) also undergoes some postnatal maturation, while phototransduction gain (log S) is adult-like at birth. Albino animals had significantly (p<0.05) larger RmP3 and log S across all ages. Guinea pigs have significant postnatal development in their receptoral response. Maturation of RmP3 implies a postnatal increase in rod outer segment length. Whereas the adult values of log S implies a mature phototransduction process at birth. We argue that the likely cause for the larger log S of albino eyes is compatible with theories of increased levels of internal light. Whereas the larger RmP3, even after allowing for increased light effectiveness, may reflect a lower ocular resistance in albino eyes due to their lower levels of melanin. Furthermore, decreased RmP3 and log S with age is observed in the pigmented group only and is consistent with increased ocular resistance due to melanin development in this strain.
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Affiliation(s)
- B V Bui
- Department of Optometry and Vision Sciences, University of Melbourne, Victoria, Australia
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Abedin L, Lien EL, Vingrys AJ, Sinclair AJ. The effects of dietary alpha-linolenic acid compared with docosahexaenoic acid on brain, retina, liver, and heart in the guinea pig. Lipids 1999; 34:475-82. [PMID: 10380119 DOI: 10.1007/s11745-999-0387-3] [Citation(s) in RCA: 99] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The aim of this study was to compare two different strategies to elevate brain, retina, liver, and heart docosahexaenoic acid (DHA) levels in guinea pigs. First, we used an increasing dose of alpha-linolenic acid (ALA) relative to a constant linoleic acid (LA) intake, and second, we used two levels of dietary DHA provided in conjunction with dietary arachidonic acid (AA). The percentage DHA and AA of total phospholipids in retina, liver, and heart, and in the brain phosphatidylethanolamine and phosphatidylcholine was studied in female pigmented guinea pigs (3 wk old) fed one of five semisynthetic diets containing 10% (w/w) lipid for 12 wk. The LA content in the diets was constant (17% of total fatty acids), with the ALA content varying from 0.05% (diet SFO), to 1% (diet Mix), and to 7% (diet CNO). Two other diets (LCP1 and LCP3) had a constant LA/ALA ratio (17.5:1) but varied in the levels of dietary AA and DHA supplementation. Diet LCP1 was structured to closely replicate the principal long chain polyunsaturated fatty acids (PUFA) found in human breast milk and contained 0.9% AA and 0.6% DHA (% of total fatty acids) whereas diet LCP3 contained 2.7% AA and 1.8% DHA. At the end of the study, animals were sacrificed and tissues taken for fatty acid analyses. We found no significant effects of diets on the growth of guinea pigs. Diets containing ALA had profoundly different effects on tissue fatty acid compositions compared with diets which contained the long chain PUFA (DHA and AA). In the retina and brain phospholipids, high-ALA diets or dietary DHA supplementation produced moderate relative increases in DHA levels. There was no change in retinal or brain AA proportions following dietary AA supplementation, even at the highest level. This was in contrast to liver and heart where tissue DHA proportions were low and AA predominated. In these latter tissues, dietary ALA had little effect on tissue DHA proportions although the proportion of AA was slightly depressed at the highest dietary ALA intake, but dietary DHA and AA supplements led to large increases (up to 10-fold) in the proportions of these PUFA. Tissue uptake of dietary AA and DHA appeared maximal for the LCP1 diet (replicate of breast milk) in the heart. There were no significant changes in the plasma levels of 11-dehydrothromboxane B2 (a thromboxane A2 metabolite) for any diet. The data confirm that dietary ALA is less effective than dietary DHA supplementation (on a gram/gram basis) in increasing tissue DHA levels and that tissues vary greatly in their response to exogenous AA and DHA, with the levels of these long chain metabolites being most resistant to change in the retina and brain compared with liver and heart. Dietary DHA markedly increased tissue DHA proportions in both liver and heart, whereas the major effect of dietary AA was in the liver. Future studies of the effects of dietary DHA and AA supplementation should examine a variety of tissues rather than focusing only on neural tissue.
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Affiliation(s)
- L Abedin
- Department of Food Science, Royal Melbourne Institute of Technology University, Victoria, Australia
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BENJAKUL S, SEYMOUR TA, MORRISSEY MT, AN H. CHARACTERIZATION OF PROTEINASE RECOVERED FROM PACIFIC WHITING SURIMI WASH WATER. J Food Biochem 1998. [DOI: 10.1111/j.1745-4514.1998.tb00227.x] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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JIANG SHANNTZONG, LEE BAILIN, TSAO CHINGYU, LEE JAIJAAN. Mackerel Cathepsins B and L Effects on Thermal Degradation of Surimi. J Food Sci 1997. [DOI: 10.1111/j.1365-2621.1997.tb03991.x] [Citation(s) in RCA: 41] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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PORTER ROY, KOURY BARBARA, STONE FRED. COMPARISON OF CATHEPSIN B, D, H AND L ACTIVITY IN FOUR SPECIES OF PACIFIC FISH. J Food Biochem 1995. [DOI: 10.1111/j.1745-4514.1995.tb00546.x] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
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Hannan F, Hall LM. Muscarinic acetylcholine receptors in invertebrates: comparisons with homologous receptors from vertebrates. EXS 1993; 63:98-145. [PMID: 8422542 DOI: 10.1007/978-3-0348-7265-2_6] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
The pharmacology, physiology and molecular biology of invertebrate muscarinic acetylcholine receptors are compared with current knowledge concerning vertebrate muscarinic acetylcholine receptors. Evidence for the existence of multiple receptor subtypes in invertebrates is examined, emphasizing what is presently known about the sensitivity of invertebrate preparations to subtype selective ligands previously defined in vertebrate studies. Other evidence for muscarinic receptor subtypes which is examined includes: heterogeneous responses to classical muscarinic ligands and evidence for coupling of invertebrate muscarinic receptors to several different classes of second messenger systems. Clues regarding possible functions for invertebrate muscarinic receptors are discussed, including evidence from both physiological studies and in situ localization studies which reveal patterns of receptor protein and mRNA expression. A detailed analysis of the structural similarities between a cloned Drosophila muscarinic receptor and vertebrate muscarinic receptors is also presented. Regions of the receptors that may be involved in ligand binding, effector coupling and receptor regulation are identified in this comparison. Future directions for invertebrate muscarinic receptor research are considered including: methods for cloning other receptor subtypes, methods for cloning homologous receptors from other species and genetic approaches for determining the physiological roles of muscarinic receptors.
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Affiliation(s)
- F Hannan
- State University of New York, School of Pharmacy, Department of Biochemical Pharmacology, Buffalo 14260
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Spira AW, Parkinson D. Effects of dark-rearing on the retinal dopaminergic system in the neonatal and postnatal guinea pig. BRAIN RESEARCH. DEVELOPMENTAL BRAIN RESEARCH 1991; 62:142-5. [PMID: 1760868 DOI: 10.1016/0165-3806(91)90200-3] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
To appraise the extent of light responsivity of the retinal dopaminergic system in the early postnatal period, dopamine content (DA) of retinas of cycling-light-reared and dark-reared guinea pigs was determined. DA storage postnatally was suppressed in dark-reared animals. Their retinas responded to a brief light stimulus by rapidly increasing DOPA synthesis and DA utilization, but not to the extent of the response of cycling-light-reared animals. Dopaminergic retinal neurones depend on light stimulus for the complete development of some of their neurochemical characteristics.
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Affiliation(s)
- A W Spira
- Department of Anatomy, University of Calgary, Alta., Canada
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