RESUMO
BACKGROUND: A low ankle-brachial pressure index (an ABPI value <0.90) is considered predictive of cardiovascular disease, and is widely thought to increase morbidity and mortality in the elderly. However, good nutrition is beneficial both for the health and the ability to resist and recover from the disease. OBJECTIVE: The aim of the present study was to evaluate the relationship between the ankle-brachial pressure index and the nutritional status of the elderly in a city of Kochi prefecture, Japan. METHODS: This was a cross-sectional study in which a total of 100 elderly people, both males and females, were screened for ankle-brachial pressure index (ABPI), nutritional status (through the use of the short form of the mini nutritional assessment), activities of daily living, lifestyle, gait speed (10MWT), postural stability (OLST), and functional mobility (TUG). RESULTS: About 67% of the participants were found to have a normal nutritional status, 27% were at risk of malnutrition, and six percent were classified as malnourished. The mean ABPI of the participants was 1.08±0.10, and three participants had an ABPI lower than 0.90. The ABPI was statistically higher in well nourished participants compared with those at risk of malnutrition or the malnourished. The mean ABPI was significantly higher in non-smokers compared with former smokers. The ABPI was found to correlate negatively with gait speed and with TUG score. CONCLUSION: Well-nourished elderly had a higher normal ankle-brachial pressure index as compared with the malnourished elderly. This study provides supportive evidence for the necessity of adequate nutrition for elderly people.
Assuntos
Índice Tornozelo-Braço , Doenças Cardiovasculares/epidemiologia , Desnutrição/epidemiologia , Avaliação Nutricional , Atividades Cotidianas , Idoso , Idoso de 80 Anos ou mais , Pressão Sanguínea , Doenças Cardiovasculares/fisiopatologia , Estudos Transversais , Feminino , Humanos , Japão , Estilo de Vida , Masculino , Desnutrição/fisiopatologia , Estado Nutricional , Prevalência , Análise de Regressão , Fatores de Risco , Inquéritos e QuestionáriosRESUMO
AIMS: Recent studies have suggested that small leucine-rich proteoglycans (SLRP) of the extracellular matrix play a major role in modulating the activity of growth factors and in regulating the deposition of collagens. In this study, the expression of the SLRPs biglycan and decorin in the glomeruli of patients with primary glomerular disease (minimal change disease, IgA nephropathy, and membranous nephropathy) and urine immunoreactive levels examined. METHODS: Renal biopsy specimens were obtained from patients with minimal change disease, IgA nephropathy and membranous nephropathy. Immunohistochemical staining was performed on fresh-frozen samples using anti-biglycan and anti-decorin antibodies. Examination of urine proteoglycan excretion from a total of 26 patients and 8 normal volunteers was performed by indirect ELISA. RESULTS: In normal kidney samples, biglycan and decorin expression was found predominantly in the intrarenal arteries and tubulointerstitium, with only minimal expression in the glomeruli. Glomerular expression of these proteoglycans in glomerular disease was unchanged in all of the 4 patients examined with minimal change disease. In the case of IgA nephropathy or membranous nephropathy, some of the patients showed minimally increased immunostaining of either biglycan or decorin, but there were no signs of simultaneous upregulation of both proteoglycans. To further examine the changes in proteoglycan expression, ELISA was performed on urine samples. Urine biglycan levels were below detection levels, but high values of urine decorin immunoreactivity were found in the patients with glomerular disease. A significant negative correlation was found between urine decorin and creatinine clearance. CONCLUSION: These results suggest that distinct changes in the expression of the SLRPs biglycan and decorin may be seen in patients with primary glomerular disease. Moreover, the negative relationship between urine decorin levels and renal function supports the hypothesis that decorin may be involved in the pathophysiology of renal dysfunction in humans.
Assuntos
Glomerulonefrite por IGA/metabolismo , Glomerulonefrite Membranosa/metabolismo , Proteoglicanas/biossíntese , Adulto , Biglicano , Decorina , Ensaio de Imunoadsorção Enzimática , Proteínas da Matriz Extracelular , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Proteoglicanas/análise , Proteoglicanas/urinaRESUMO
The first objective of this study was to examine the intermediary metabolism of plasma amino acids and keto acids in streptozotocin (STZ)-treated rats. Plasma alpha-aminobutyrate (alpha-ABA) concentration in STZ rats was 1.5-fold greater than in control (CNT) animals at 1 month. In contrast, the level of plasma alpha-ketobutyrate (KB), which is transaminated to alpha-ABA, did not differ significantly between STZ and CNTs at 1 month, and also increased with age. Additionally, HPLC analysis revealed consistent profiles containing peaks of unknown origin. Two pathways exist for the formation of alpha-KB, either from the action of threonine dehydratase or via homocysteine, the latter metabolite being closely associated with the development of cardiovascular disease. These observations suggest that uncharacterized metabolites, including plasma alpha-KB, may be potential risk factors for the development of diabetic complications. We carried out preparatory experiments on non-diabetic rats to investigate the influence of alpha-KB and confirmed this metabolite had no adverse effects. The second aim of the study was to compare vascular wall thickness in diabetic rats treated or untreated with alpha-KB with CNT animals in order to determine the effects of alpha-KB on the renal microvasculature. The thickness of the medial wall of arterioles and small arteries differed significantly among all groups and was increased, especially in the small arterial walls of the diabetic rats treated with alpha-KB. Plasma renin activities (PRA) in both diabetic rats treated or untreated with alpha-KB were decreased significantly compared to CNT animals, while diabetic rats treated with alpha-KB had higher angiotensin converting enzyme (ACE) activity than the CNT group (p < 0.01). These results suggest that alpha-KB may have a role in the renal microvascular complications of diabetes.
Assuntos
Butiratos/farmacologia , Diabetes Mellitus Experimental/patologia , Rim/irrigação sanguínea , Animais , Vasos Sanguíneos/efeitos dos fármacos , Vasos Sanguíneos/patologia , Epitélio/efeitos dos fármacos , Epitélio/patologia , Masculino , Microcirculação/efeitos dos fármacos , Ratos , Ratos WistarRESUMO
The localization of heme oxygenase-2 (HO-2) in the larynx of the dog was investigated using immunohistochemistry. HO-2-positive cells were seen among neurons in intralaryngeal ganglia. Nerve fibers positive to HO-2 immunohistochemistry were seen surrounding laryngeal glands and arterioles and also in the adventitia of arterioles. HO-2-positive fibers were also seen running parallel to the mucosa in the lamina propria but no positive fibers were seen in the epithelium. Some of the intramuscular neurons found in the intrinsic laryngeal muscles were HO-2-positive, although no positive motor fibers were seen, and the neuromuscular junctions were also HO-2-negative. The results implicate the participation of HO-2-in the parasympathetic innervation of the larynx.
Assuntos
Heme Oxigenase (Desciclizante)/análise , Nervos Laríngeos/patologia , Laringe/patologia , Animais , Cães , Feminino , Técnicas Imunoenzimáticas , Masculino , Fibras Nervosas/patologia , Neurônios/patologia , Valores de Referência , Transmissão Sináptica/fisiologiaRESUMO
Proteoglycans are an important component of the extracellular matrix, and are thought to play multiple roles not only in kidney remodeling, but also in regulating glomerular permeability, and in modulating the activity of other cytokines and growth factors. The aim of this study was to examine the gene expressions of proteoglycan core proteins in hypertensive rat kidneys, and their modulation by AT1 receptor antagonist. SHRSP/Izm rats and normotensive control WKY/Izm rats on a normal salt diet were treated with or without the AT1 receptor antagonist candesartan cilexetil (1 mg/kg/day) from 10 weeks to 22 weeks. At the end of the treatment period, renal tissue was excised, and gene expressions of the proteoglycan core proteins versican, perlecan, decorin, and biglycan were examined by Northern blot analysis and RT-PCR. Treatment with candesartan cilexetil caused significant decreases in blood pressure and amelioration of proteinuria and renal histological scores in the SHRSP/Izm rats. Compared to WKY/Izm rats, expression of biglycan mRNA showed a small increase in SHRSP/Izm rats which did not attain statistical significance. On the other hand, treatment with candesartan caused significant reductions in biglycan and decorin mRNA in the SHRSP/Izm rats. In contrast, the level of versican mRNA appeared to be increased after candesartan treatment. These results suggest that treatment with AT1 receptor antagonist was associated with diverse changes in renal proteoglycan gene expression in SHRSP/Izm rats. These changes could contribute to the beneficial effects of AT1 receptor antagonist on tissue remodeling and inhibition of disease progression in hypertensive rat kidneys.
Assuntos
Antagonistas de Receptores de Angiotensina , Anti-Hipertensivos/farmacologia , Benzimidazóis/farmacologia , Compostos de Bifenilo/farmacologia , Hipertensão Renal/tratamento farmacológico , Hipertensão Renal/fisiopatologia , Proteoglicanas/genética , Tetrazóis , Animais , Biglicano , Pressão Sanguínea/efeitos dos fármacos , Proteoglicanas de Sulfatos de Condroitina/genética , Decorina , Proteínas da Matriz Extracelular , Expressão Gênica/efeitos dos fármacos , Proteoglicanas de Heparan Sulfato/genética , Rim/fisiopatologia , Lectinas Tipo C , Masculino , Nefroesclerose/tratamento farmacológico , Nefroesclerose/fisiopatologia , RNA Mensageiro/análise , Ratos , Ratos Endogâmicos SHR , Ratos Endogâmicos WKY , Receptor Tipo 1 de Angiotensina , Receptor Tipo 2 de Angiotensina , VersicanasRESUMO
Previously, we and others have shown that angiotensin II enhances vascular smooth muscle cell extracellular matrix synthesis via stimulation of the angiotensin II type 1 (AT(1)) receptor. Recently, expression of the type 2 (AT(2)) receptor has been confirmed in the adult vasculature, but its role has not yet been fully defined. The aim of the present study was to examine the effects of stimulation of AT(2) receptors on collagen synthesis in vascular smooth muscle cells. Retroviral gene transfer was used to supplement adult vascular smooth muscle cells with AT(2) receptors to mimic the vasculature in vivo. The treatment of these cells with the AT(2) receptor agonist CGP42212A (10(-7) mol/L) alone did not cause a significant change in p42/p44 MAP kinase activity but caused a modest (30% to 50%) decrease in protein tyrosine phosphatase activity. Treatment with CGP42112A also caused a dose- and time-dependent increase in both cell-associated and secretory collagen synthesis (148+/-17% of control at 48 hours, P<0.05), which was completely inhibited by the AT(2) receptor antagonist PD123319, unaffected by the AT(1) receptor antagonist losartan, and attenuated by treatment with pertussis toxin or G(alpha)(i) antisense oligonucleotides. Interestingly, studies in other cell lines demonstrated that CGP42112A caused similar results in transfected mesangial cells but had essentially opposite effects in fibroblasts (NIH-3T3-AT(2)). These results suggest that AT(2) receptor stimulation can increase collagen synthesis in vascular smooth muscle cells via a G(alpha)(i)-mediated mechanism and provide evidence for heterogeneity in the effects of AT(2) receptor stimulation in different tissues.
Assuntos
Colágeno/biossíntese , Músculo Liso Vascular/citologia , Receptores de Angiotensina/fisiologia , Animais , Células Cultivadas , Matriz Extracelular/efeitos dos fármacos , Matriz Extracelular/metabolismo , Fibroblastos/efeitos dos fármacos , Fibroblastos/fisiologia , Losartan/farmacologia , Masculino , Proteína Quinase 1 Ativada por Mitógeno/metabolismo , Músculo Liso Vascular/efeitos dos fármacos , Músculo Liso Vascular/metabolismo , Oligonucleotídeos Antissenso/farmacologia , Oligopeptídeos/farmacologia , Proteínas Tirosina Quinases/metabolismo , Ratos , Ratos Wistar , Receptores de Angiotensina/efeitos dos fármacos , Tionucleotídeos/farmacologiaRESUMO
The ammonia-oxidizing bacterium Nitrosomonas sp. strain ENI-11 contains three copies of the hao gene (hao1, hao2, and hao3) coding for hydroxylamine oxidoreductase (HAO). Three single mutants (hao1::kan, hao2::kan, or hao3::kan) had 68 to 75% of the wild-type growth rate and 58 to 89% of the wild-type HAO activity when grown under the same conditions. A double mutant (hao1::kan and hao3::amp) also had 68% of the wild-type growth and 37% of the wild-type HAO activity.
Assuntos
Nitrosomonas/enzimologia , Nitrosomonas/genética , Oxirredutases/genética , Análise Mutacional de DNA , DNA Bacteriano/química , Nitrosomonas/crescimento & desenvolvimento , Reação em Cadeia da PolimeraseRESUMO
We analyzed beta-glucosidase-catalyzed transglucosylation to D-pantothenic acid using a reversed-phase HPLC system in order to obtain 4'-O-(beta-D-glucopyranosyl)-D-pantothenic acid (PaG) at a higher yield. The HPLC system was simpler and more straight-forward for the PaG analysis than the previously employed bioassay method and could also be adopted for efficient isolation of PaG. Penicillium decumbens naringinase showed the highest glucosyl transfer activity to D-pantothenic acid, and the reaction using smaller amounts of naringinase for prolonged periods of reaction time (70 h<) was important to attain higher yields of glucosyl transfer. Maximum overall yields of PaG of 10 and 4% (mol/mol, based on D-pantothenic acid) were obtained using beta, beta'-trehalose and cellobiose, respectively, as glucosyl donors. The value was 3.6- and 1.4-times higher, respectively, than that obtained by previous synthesis and isolation procedures.
Assuntos
Ácido Pantotênico/análise , Ácido Pantotênico/metabolismo , beta-Glucosidase/metabolismo , Animais , Aspergillus niger/enzimologia , Celobiose/metabolismo , Celulase/metabolismo , Cromatografia Líquida de Alta Pressão/métodos , Glicosídeo Hidrolases/metabolismo , Complexos Multienzimáticos/metabolismo , Ácido Pantotênico/análogos & derivados , Ácido Pantotênico/biossíntese , Ácido Pantotênico/isolamento & purificação , Penicillium/enzimologia , Trealose/metabolismoRESUMO
Macrophages (Mphis), but not T cells, infiltrating into the rejection site of either i.p. allografted Meth A (H-2d) fibrosarcoma cells in C57BL/6 (B6) (H-2b) mice or BALB/c (H-2d) skin onto B6 mice are cytotoxic against allografts with H-2d specificity. To determine the mechanisms of specific killing of allografts by allograft-induced Mphi (AIM), we raised approximately 5,000 rat monoclonal antibodies (mAbs) against AIM and selected three of them (R1-73, R2-40 and R1-34), each of which inhibited cytotoxic activity against allografts in a dose-dependent manner. The antigens recognized by R1-73, R2-40 and R1-34 mAbs were defined by immunoprecipitation and Western blot analyses as CD11a, CD18 and CD11b, respectively; and the allografts expressed CD54, a ligand of CD11a or CD11b, suggesting leukocyte integrin-dependent killing. Although Ab-dependent cellular cytotoxicity has been recognized as a mechanism of specific killing by Mphis, the infiltration of AIM into the rejection site of allografts far (approximately 6 days) preceded the appearance of serum IgG Ab specific for the allograft. AIM exhibiting full cytotoxic activity against allografts was also induced in the transplantation site of Fcgamma receptor knockout [(B6x129) F1] mice as well as B10.D2 (H-2 compatible with allograft) and B6-xid (X-linked immunodeficiency with B cell-specific defect) strains of mice. In the latter two strains of mice, the levels of serum IgG Ab to the allograft were negligible. Moreover, the cytotoxic activity of AIM against allografts was not affected by pretreatment of the cells with anti-mouse IgG serum, suggesting Ab-independent cytotoxicity.
Assuntos
Antígenos CD11/imunologia , Antígenos CD18/imunologia , Citotoxicidade Imunológica/imunologia , Rejeição de Enxerto/imunologia , Macrófagos/imunologia , Transplante de Pele/imunologia , Transplante Homólogo/imunologia , Animais , Anticorpos Monoclonais/imunologia , Antígenos H-2/imunologia , Antígeno de Histocompatibilidade H-2D , Leucócitos/imunologia , Antígeno-1 Associado à Função Linfocitária/imunologia , Antígeno de Macrófago 1/imunologia , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Transplante de Neoplasias/imunologia , Ratos , Pele/imunologia , Células Tumorais CultivadasRESUMO
The allene oxide synthase (AOS) was purified from corn (Zea mays) seeds to homogeneity and characterized partially. The corn AOS was a hemoprotein cytochrome P450 with a molecular weight and pI of 53,000 and 6.0, respectively. The corn AOS was found to be irreversibly inactivated by a substrate, 13-hydroperoxyoctadienoic acid. The rate of the enzyme inactivation was higher at low pHs.
Assuntos
Oxirredutases Intramoleculares/isolamento & purificação , Zea mays/enzimologia , Oxirredutases Intramoleculares/antagonistas & inibidores , Sementes/enzimologia , Especificidade por SubstratoRESUMO
Pulsed-field gel electrophoresis of PmeI digests of the Nitrosomonas sp. strain ENI-11 chromosome produced four bands ranging from 1,200 to 480 kb in size. Southern hybridizations suggested that a 487-kb PmeI fragment contained two copies of the amoCAB genes, coding for ammonia monooxygenase (designated amoCAB(1) and amoCAB(2)), and three copies of the hao gene, coding for hydroxylamine oxidoreductase (hao(1), hao(2), and hao(3)). In this DNA fragment, amoCAB(1) and amoCAB(2) were about 390 kb apart, while hao(1), hao(2), and hao(3) were separated by at least about 100 kb from each other. Interestingly, hao(1) and hao(2) were located relatively close to amoCAB(1) and amoCAB(2), respectively. DNA sequence analysis revealed that hao(1) and hao(2) shared 160 identical nucleotides immediately upstream of each translation initiation codon. However, hao(3) showed only 30% nucleotide identity in the 160-bp corresponding region.
Assuntos
Mapeamento Cromossômico , Nitrosomonas/enzimologia , Oxirredutases/genética , DNA Bacteriano/química , Desoxirribonucleases de Sítio Específico do Tipo II/metabolismo , Eletroforese em Gel de Campo Pulsado , Dados de Sequência Molecular , Nitrosomonas/genética , Mapeamento por Restrição , Análise de Sequência de DNARESUMO
Two plasmids were discovered in the ammonia-oxidizing bacterium Nitrosomonas sp. strain ENI-11, which was isolated from activated sludge. The plasmids, designated pAYS and pAYL, were relatively small, being approximately 1.9 kb long. They were cryptic plasmids, having no detectable plasmid-linked antibiotic resistance or heavy metal resistance markers. The complete nucleotide sequences of pAYS and pAYL were determined, and their physical maps were constructed. There existed two major open reading frames, ORF1 in pAYS and ORF2 in pAYL, each of which was more than 500 bp long. The predicted product of ORF2 was 28% identical to part of the replication protein of a Bacillus plasmid, pBAA1. However, no significant similarity to any known protein sequences was detected with the predicted product of ORF1. pAYS and pAYL had a highly homologous region, designated HHR, of 262 bp. The overall identity was 98% between the two nucleotide sequences. Interestingly, HHR-homologous sequences were also detected in the genomes of ENI-11 and the plasmidless strain Nitrosomonas europaea IFO14298. Deletion analysis of pAYS and pAYL indicated that HHR, together with either ORF1 or ORF2, was essential for plasmid maintenance in ENI-11. To our knowledge, pAYS and pAYL are the first plasmids found in the ammonia-oxidizing autotrophic bacteria.
Assuntos
Amônia/metabolismo , Nitrosomonas/genética , Plasmídeos/genética , Sequência de Aminoácidos , Proteínas de Bactérias/genética , Sequência de Bases , Replicação do DNA , DNA Recombinante/genética , Dosagem de Genes , Genes Bacterianos/genética , Marcadores Genéticos/genética , Resistência a Canamicina/genética , Dados de Sequência Molecular , Nitrosomonas/metabolismo , Fases de Leitura Aberta/genética , Oxirredução , Análise de Sequência de DNA , Deleção de Sequência , Homologia de Sequência , Transformação BacterianaRESUMO
Intestinal ornithine transcarbamylase (OTC) activity was studied in rats with experimentally-induced diabetes. After the injection of streptozotocin, OTC activity was approximately 75% that of age-matched controls. Then we investigated the influences of (a) insulin treatment and (b) limiting food-intake, which was adjusted to the control level, on OTC activities in the three segments of the small intestine. (a) Insulin treatment resulted in OTC activities being restored to control levels in all segments of the small intestine, with the disappearance of intestinal epithelial hyperplasia. (b) In limited food-intake rats, OTC activities of the middle and distal segments normalized with insulin treatment. In the proximal segment, however, which showed epithelial hyperplasia, OTC activity was as low as that in untreated STZ rats. These observations suggest that altered regulation of intestinal epithelial over-growth and immoderate food-intake were normalized by insulin treatment, leading to the restoration of normal OTC activity in the small intestine.
Assuntos
Diabetes Mellitus Experimental/tratamento farmacológico , Diabetes Mellitus Experimental/enzimologia , Ingestão de Alimentos , Hipoglicemiantes/farmacologia , Insulina/farmacologia , Ornitina Carbamoiltransferase/efeitos dos fármacos , Análise de Variância , Animais , Glicemia/efeitos dos fármacos , Glicemia/metabolismo , Peso Corporal/efeitos dos fármacos , Intestinos/efeitos dos fármacos , Intestinos/enzimologia , Fígado/efeitos dos fármacos , Fígado/enzimologia , Masculino , Ornitina Carbamoiltransferase/metabolismo , Ratos , Ratos Wistar , Fatores de TempoRESUMO
We investigated the bone metabolic system status of 103 male and female volunteer collegiate athletes, who were actively pursuing one of three different sports: Long-distance running (LR); judo (JU); and swimming (SW). The following parameters were evaluated: total body bone mineral density (TMBD); bone-forming metabolic markers; serum procollagen type I C-peptide (PICP) levels; bone alkaline phosphatase (B-ALP) content; bone resorption markers, urinary pyridinoline (Pyd) and deoxypyridinoline (Dpd) levels. We found that the TBMD and urinary Dpd values in JU athletes were significantly higher (p < 0.001) than in athletes of the same sex in the other two groups. The urinary Pyd level in male JU athletes was also higher (p < 0.001) than that in the other two groups, but that in females JU athletes was only higher (p < 0.01) than that in female LR athletes. The PICP levels were similar to the TBMD values in all groups. No differences in bone density or in bone metabolic markers were seen in LR and SW athletes of the same sex. We thus conclude that differences in bone mineral density are in part due to the demands of the specific sport, and that they are reflected in bone metabolic markers. In addition, the status of bone metabolic turnover in male JU athletes in training may be hypermetabolic and as well as that of female JU athletes with regular menses cycles.
Assuntos
Densidade Óssea , Osso e Ossos/metabolismo , Artes Marciais/fisiologia , Corrida/fisiologia , Natação/fisiologia , Adulto , Feminino , Humanos , MasculinoRESUMO
We have used special tests to investigate taste function in detail. To evaluate acuity for a salty taste, we used a paper with salt crystals, Salsave. The procedure is simple and takes only a few minutes. We analyzed the relationships between the magnitude of the threshold of response to this test and the results of other taste function tests in 126 patients who visited our clinic. The mean magnitude of the response to Salsave significantly correlated with the results of other taste tests. Thus, this is a useful method for screening the detection and recognition threshold of a salty taste.
Assuntos
Fitas Reagentes , Cloreto de Sódio , Distúrbios do Paladar/diagnóstico , Adulto , Idoso , Idoso de 80 Anos ou mais , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Limiar GustativoRESUMO
To understand the mechanism of the phototoxic effects of inperatorin, a psoralen derivative used as a pigmentation agent, we have investigated the photosensitized oxidation of arachidonic acid (ARA) by irradiation with visible light (> 400 nm) in the presence of inperatorin. HPLC and GC/MS analyses of the products showed the formation of many hydroperoxyeicosatetraenoic acids (HPETEs) including the products of lipoxygenase-catalyzed reactions such as 5- and 15-HPETEs, which are the precursors of chemical mediators such as leukotrienes and lipoxins, during the reaction. Active oxygen scavening agents such as D-mannitol, superoxide dismutase, and beta-carotene inhibited the formation of the oxidation products, indicating that the oxidation reaction was mediated by various active oxygen species. These results suggest that the phototoxic effects of inperatorin could also be induced by visible light and could be explained at least partially in terms of inflammation initiated by the biologically active HPETEs arising from photosensitized oxygenation reactions of ARA with the drug.
Assuntos
Ácido Araquidônico/química , Furocumarinas/química , Luz , Fármacos Fotossensibilizantes/química , Boroidretos/química , Carotenoides/farmacologia , Cromatografia Líquida de Alta Pressão , Furocumarinas/toxicidade , Cromatografia Gasosa-Espectrometria de Massas , Leucotrienos/química , Peróxidos Lipídicos/química , Manitol/farmacologia , Oxirredução , Fotoquímica , Fármacos Fotossensibilizantes/toxicidade , Espécies Reativas de Oxigênio/química , Superóxido Dismutase/farmacologia , beta CarotenoRESUMO
Effects of deficiency in ascorbic acid on in vivo production of corticosterone and testosterone were examined using a mutant strain of rats unable to synthesize ascorbic acid. The adrenal weight of scorbutic rats was larger, and corticosterone levels in plasma and adrenal tissues were higher than those of ascorbic acid-supplied (ascorbutic) rats. Acute and chronic stimulation with ACTH increased corticosterone levels in both ascorbutic and scorbutic rats. In contrast, weights of seminal vesicles and ventral prostates in unstimulated scorbutic rats were smaller, and testosterone levels in plasma and testicular tissues were lower than those in ascorbutic rats. Acute stimulation with hCG increased testosterone levels only slightly in plasma and not in testicular tissues of scorbutic rats, when testosterone levels in ascorbutic rats reached a maximum. Chronic stimulation with hCG increased testosterone levels remarkably in both ascorbutic and scorbutic rats. These findings seem to indicate that ascorbic acid is not essential for the synthesis of steroid hormones. The scurvy seems to increase plasma ACTH levels secondary to the stress, resulting in the stimulation of the adrenals. In contrast, a prolonged deficiency in ascorbic acid appears to decrease plasma gonadotropin levels, and may reduce the sensitivity of testes to gonadotropins.
Assuntos
Glândulas Suprarrenais/metabolismo , Ácido Ascórbico/metabolismo , Cortisona/metabolismo , Testículo/metabolismo , Testosterona/metabolismo , Glândulas Suprarrenais/química , Glândulas Suprarrenais/fisiologia , Hormônio Adrenocorticotrópico/sangue , Hormônio Adrenocorticotrópico/farmacologia , Animais , Ácido Ascórbico/fisiologia , Peso Corporal/fisiologia , Gonadotropina Coriônica/sangue , Gonadotropina Coriônica/farmacologia , Ritmo Circadiano/fisiologia , Cortisona/análise , Cortisona/sangue , Relação Dose-Resposta a Droga , Masculino , Tamanho do Órgão/fisiologia , Próstata/anatomia & histologia , Ratos , Ratos Mutantes , Glândulas Seminais/anatomia & histologia , Testículo/química , Testículo/fisiologia , Testosterona/análise , Testosterona/sangueRESUMO
The effect of physical training on thrombotic tendency was assessed in rats. Exercise was done on a flat treadmill for 30 min at a rate of 1,400 m/h (submaximal speed), 5 times a week for either 1.5 or 3 months. The thrombotic tendency was measured by the He-Ne laser-induced thrombus formation method in microvessels of mesentery, i.e. measurement of the number of laser irradiations necessary to induce stasis of blood flow by occlusive thrombus formation. An increase in the number of irradiations necessary to induce occlusive thrombus formation was observed in arterioles, but not in venules after physical training for 1.5 and 3 months.
Assuntos
Artérias/fisiopatologia , Arteríolas/fisiopatologia , Condicionamento Físico Animal , Trombose/prevenção & controle , Veias/fisiopatologia , Vênulas/fisiopatologia , Animais , Arteríolas/efeitos da radiação , Lasers , Masculino , Ratos , Ratos Endogâmicos , Trombose/etiologia , Vênulas/efeitos da radiaçãoAssuntos
Hormônio Adrenocorticotrópico/metabolismo , Colecistocinina/farmacologia , Hormônios Gastrointestinais/antagonistas & inibidores , Fragmentos de Peptídeos/farmacologia , Peptídeo Intestinal Vasoativo/antagonistas & inibidores , Animais , Corticosterona/sangue , Hormônio Liberador da Corticotropina/farmacologia , Masculino , Ratos , Ratos Endogâmicos , SincalidaRESUMO
Intraperitoneal (i.p.) injection of C-terminal octapeptide of cholecystokinin (CCK-8) produced a dose-related increase in plasma corticosterone levels in intact rats, but not in vagotomized ones. Intracerebroventricular (i.c.v.) injection of CCK-8 was ineffective in stimulating the secretion of corticosterone, and in vitro experiment on ACTH release indicated that CCK-8 could not affect pituitary tissue directly. Since i.p. injection of non-sulfated CCK-8 failed to elevate plasma corticosterone levels, sulfated tyrosine residue in the CCK molecule is assumed to be indispensable for the stimulation of visceral organs. On the other hand, vasoactive intestinal polypeptide (VIP) was found to cause a dose-dependent increase in plasma corticosterone levels when administered centrally, but not after i.p. injection. However, VIP could not stimulate the release of ACTH from the pituitary tissue directly. The results suggest that VIP, but not CCK, stimulates the hypothalamic CRF neurons either directly or indirectly.