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Item Metadata only Melatonin and the development of circadian and seasonal rhythmicity(Blackwell Scientific, 1995) McMillen, Isabella Caroline; Houghton, Daniel Charles; Young, Ian RossItem Metadata only Pulmonary surfactant lipids in the faveolar and saccular lung regions of the snakes(University of Chicago Press, 1995) Daniels, Christopher Brian; Smits, Allan W.; Orgeig, SandraItem Metadata only Reflex control of human jaw muscles by the mechanoreceptors in the periodontium(Plenum Press, 1995) Brodin, Pal; Turker, Kemal Sitki; School of Molecular and Biomedical Science : PhysiologyItem Metadata only Insights into the control of the human masticatory muscles from single motor unit recordings(Elsevier, 1995) Miles, T.; Morimoto, T.; Matsuya, T.; Takada, K.Item Metadata only Purified omega-3 fatty acids retard the development of proteinuria in salt-loaded hypertensive rats(LIPPINCOTT WILLIAMS & WILKINS, 1995) Rayner, T.; Howe, P.Objective
To determine whether purified omega-3 and omega-6 fatty acids influence the progression of hypertensive renal failure in salt-loaded stroke-prone spontaneously hypertensive rats (SHRSP) with established hypertension or during the developmental stage of their hypertension.Design
Groups of eight SHRSP aged 1 or 4 months were fed, for 12 weeks, synthetic diets containing 2% sodium (wt:wt) and either 5% olive oil or 4.5% gamma-linolenic acid (omega-6), eicosapentaenoic acid (omega-3) or docosahexaenoic acid (omega-3).Methods
Urinary protein excretion and blood pressure were measured after 6, 9 and 12 weeks. The rats were killed and their tissues were collected for fatty acid and eicosanoid analysis.Results
Young rats (aged 1 month) fed diets containing gamma-linolenic acid or olive oil developed marked proteinuria by 9 weeks, whereas no change was observed after 12 weeks in rats fed docosahexaenoic acid or eicosapentaenoic acid. Blood pressure was lower in those fed docosahexaenoic acid or eicosapentaenoic acid than in the gamma-linolenic acid or olive oil groups. Adult rats (aged 4 months) fed the docosahexaenoic acid diet had significantly lower proteinuria than those fed gamma-linolenic acid, eicosapentaenoic acid or olive oil, but there were no differences in blood pressure among the groups. Kidneys from rats fed omega-3 fatty acids had increased levels of docosahexaenoic acid or eicosapentaenoic acid, or both, whereas those from rats fed gamma-linolenic acid and olive oil contained virtually no omega-3 fatty acids. Thromboxane B2 and 12-hydroxyeicosatetraenoic acid production in renal cortex extracts was lowest in rats fed docosahexaenoic acid and eicosapentaenoic acid.Conclusion
Dietary omega-3 fatty acids retard the development of hypertension-induced proteinuria. This may be caused by a favourable influence on fatty acid and eicosanoid metabolism and reduction of blood pressure.Item Metadata only The shape of the membrane potential trajectory in tonically-active human motoneurones(Raven Press, 1995) Turker, Kemal SitkiItem Metadata only The effect of temperature and hypoxia/hypercapnia on the respiratory pattern of the unrestrained lizard, Pogona vitticeps(CSIRO, 1995) Crafter, S.; Soldini, M.; Daniels, Christopher Brian; Smits, Allan W.Item Metadata only The evolutionary significance of pulmonary surfactants in lungfish (Dipnoi)(1995) Orgeig, Sandra; Daniels, Christopher BrianItem Metadata only Pulmonary-type surfactant and the evolution of air-breathing(University of Chicago Press, 1995) Daniels, Christopher Brian; Orgeig, Sandra; Smits, Allan W.Item Metadata only Effect of hyperpnea on the cholesterol to disaturated phospholipid ratio in alveolar surfactant of rats(1995) Orgeig, Sandra; Barr, Heather A.; Nicholas, Terence E.Hyperpnea induced by swimming rats for 30 min decreased the choksterol/disaturated phospholipid ratio (CHOL/DSP) in the tubular myelin-poor fraction (alv-2), but did not affect the tubular myelin-rich fraction (alv-1). The phenomenon was further illustrated by the marked inverse relationship between CHOLIDSP and DSP. Because such a result could reflect differential release, processing, or reuptake within the alveolar compartment, this study further explored the mechanism in the rat isolated perfused lung (IPL), using radiolabeled CHOL (3H) and DSP (14C). The study also examined whether the decrease in CHOLIDSP with swimming was associated with the increase in either tidal volume (VT), frequency of breathing (f), or both. It was found that whereas a 2.5-fold increase in VTfor 15 min in the IPL increased the CHOL/DSP in alv-1 and decreased it in alv-2, a 3-fold increase in f markedly increased the CHOLIDSP in both alveolar subtractions. In apparent contrast, the increases in both VT and f markedly depressed the ratio of the sp act of CHOLIDSP, reflecting a large decrease in the sp act of CHOL in the alveolar compartment. In view of the acute nature of these IPL experiments, it is suggested that the changes reflect the differential release of CHOL and DSP. Furthermore, the marked decrease in sp act of CHOL must reflect a second source of CHOL supplying the alveolar compartment with sterol of low sp act. It is concluded that there is differential handling of surfactant CHOL and DSP in the alveolar compartment of the rat and that the decrease in CHOL/DSP with swimming is due to an increase in VT.Item Metadata only Plasma adrenaline responses to long-term modification of blood pressure in normotensive and hypertensive rats(RAPID SCIENCE PUBLISHERS, 1995) Jablonskis, L.; Howe, P.To examine the relationship between plasma adrenaline and hypertension. DESIGN: Plasma adrenaline responses to chronic manipulations of blood pressure were tested in normotensive and in hypertensive rats. METHODS: Hypertension was induced in normotensive Wistar-Kyoto (WKY) rats by administration of the nitric oxide synthase inhibitor NG-nitro-L-arginine methyl ester (L-NAME), and blood pressure was lowered in stroke-prone spontaneously hypertensive rats (SHRSP) by administering hydralazine. Plasma catecholamine responses were monitored using blood samples from conscious unrestrained rats under resting conditions. RESULTS: Twenty-four hours after starting L-NAME treatment, mean arterial pressure was 22 mmHg higher than in control WKY rats. Heart rate and plasma noradrenaline were reflexly reduced, but plasma adrenaline was unaffected. After 4 weeks of L-NAME treatment mean arterial pressure was 48 mmHg higher than in untreated rats. At this stage heart rate had returned to normal, but plasma noradrenaline was 33% higher and plasma adrenaline was 117% higher than in untreated rats. The elevation of plasma adrenaline was confirmed in a study of longer duration, in which plasma adrenaline had doubled after 10 weeks of L-NAME treatment. Conversely, 24 h after hydralazine treatment in SHRSP, mean arterial pressure was reduced by 49 mmHg and there was a reflex elevation of plasma adrenaline, noradrenaline and heart rate. However, after 19 days of blood pressure reduction with hydralazine, plasma noradrenaline and heart rate had returned to normal, but plasma adrenaline had fallen to 30% below normal. Most of the change in mean arterial pressure observed with either chronic L-NAME or hydralazine could be attributed to modulation of neurally mediated vasoconstriction, estimated from mean arterial pressure responses to acute autonomic blockade. CONCLUSION: Selective changes in plasma adrenaline levels were induced by chronic experimental manipulations of blood pressure. This implies that the high plasma adrenaline level observed in spontaneously hypertensive rats might be a consequence rather than a cause of their hypertension.Item Metadata only Hyperexcitability in CA1 of the rat hippocampal slice following hypoxia or adenosine(Elsevier Science Ltd, 1995) Doolette, David J.; Kerr, David Ian BevissItem Metadata only Different types of ganglion cell in the cardiac plexus of guinea-pigs(Cambridge University Press, 1995) Edwards, F. R.; Hirst, G. D. S.; Klemm, Megan F.; Steele, Penelope A.Item Metadata only Response of prolactin to different photoperiods after surgical disconnection of the hypothalamus and pituitary in the sheep fetus(Blackwell Scientific Publications, 1995) Houghton, Daniel Charles; Young, Ian Ross; McMillen, Isabella CarolineItem Metadata only The evolution of the surfactant system in the Reptilia(1995) Daniels, Christopher Brian; Orgeig, Sandra; Smits, Allan W.Item Metadata only Evidence for hypothalamic control of the diurnal rhythms in prolactin and melatonin in the fetal sheep during late gestation(Thomas, 1995) Houghton, Daniel Charles; Young, Ian Ross; McMillen, Isabella CarolineItem Metadata only Effect of gestational age and cortisol on the in vitro output of ACTH precursors and ACTH 1-39 from the anterior pituitary of the fetal sheep(Journal for Endocrinology Ltd., 1995) McMillen, Isabella Caroline; Merei, J. J.; White, Andy; Crosby, S.; Schwartz, JeffreyItem Metadata only Reduced motor unit activation of muscle spindles and tendon organs in the immobilized cat tibialis posterior muscle(American Physiological Society, 1995) Nordstrom, M.; Enoka, R.; Callister, R.; Reinking, R.; Stuart, D.Item Metadata only Impact of gestational age on the catecholamine responses of the fetal sheep adrenal to cholinergic stimulation in vitro(Cambridge University Press, 1995) Butler, Timothy G.; Simonetta, Giuseppe; Roberts, Michael Lawrence; McMillen, Isabella CarolineItem Metadata only Functional significance and control of release of pulmonary surfactant in the lizard lung(American Physiological Society, 1995) Wood, Philip G.; Daniels, Christopher Brian; Orgeig, Sandra