| 11. |
- Andersson, Sven, et al.
(författare)
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Effects of intravenous calcitonin gene-related peptide (CGRP) and substance P on the blood-aqueous barrier in the rabbit
- 1989
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Ingår i: Acta Physiologica Scandinavica. - 0001-6772. ; 135:3, s. 349-357
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Tidskriftsartikel (refereegranskat)abstract
- The irritation response of the rabbit eye to trigeminal nerve stimulation, which includes a breakdown of the blood-aqueous barrier (BAB), seems to be due to the release of substance P (SP) and calcitonin gene-related peptide (CGRP). In order to assess the relative importance of these two peptides for the barrier effect, and the role of arachidonic acid metabolites (AAM) in the response, we have studied the effects of intravenous injections of the peptides on the permeability of the blood vessels of the anterior uvea and the BAB using labelled albumins. At a dose of 120 pmol kg-1 there was marked leakage of labelled albumin into the aqueous humour in animals under pentobarbital anaesthesia. The leakage was enhanced by sympathotomy. In conscious animals 5 pmol kg-1 CGRP caused enhanced leakage from the blood vessels of the ciliary processes in those pre-treated with biperiden in order to abolish the cholinergic vasoconstrictor tone in the anterior uvea. 24 and 120 pmol kg-1 CGRP caused marked leakage of albumin and a breakdown of the epithelial part of the BAB. These effects were not modified by biperiden pre-treatment, but markedly reduced by pre-treatment with indomethacin. The protecting effect of indomethacin was lost when biperiden was given as well. SP did not cause a leakage with 5 nmol kg-1 and only moderate leakage with 25 nmol kg-1. This effect was abolished by pre-treatment with indomethacin but not if indomethacin was combined with biperiden.(ABSTRACT TRUNCATED AT 250 WORDS)
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| 12. |
- Andersson, Sven
(författare)
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Effects of intravenous calcitonin gene-related peptide (CGRP) on local blood flow in the cat
- 1989
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Ingår i: Acta Physiologica Scandinavica. - 0001-6772. ; 137:2, s. 259-270
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Tidskriftsartikel (refereegranskat)abstract
- The effects of i.v. calcitonin gene-related peptide (CGRP) on regional blood flow, vascular resistance, heart rate and cardiac output in cats were studied using the microsphere method. Three series of experiments were performed. In the first there was no pre-treatment of the animals. In the second the animals were pre-treated with indomethacin (5 mg kg-1) in order to prevent the formation of prostaglandins. In the third series the ganglionic blocking agent hexamethonium bromide (80 mg kg-1) was given in order to prevent autonomic reflexes. CGRP was given as an i.v. infusion. Two doses were tested in each series. Animals with no pre-treatment and those pre-treated with indomethacin received first 60 pmol kg-1 infused over a 5-min period and then 180 pmol kg-1 infused over a 3-min period. Animals under ganglionic blockade received the same dose as the total infusions in the other series (240 pmol kg-1) infused over 4 min and a second infusion of 1.2 nmol kg-1 over 5 min. Vasodilatory effects were observed in most of the tissues tested, but there were marked differences in sensitivity. The most sensitive tissues seemed to be the lacrimal, submandibular and parotid glands, the nictitating membrane, the tongue and the gallbladder. The patterns of sensitivity were similar in all the series, indicating that neither prostaglandins nor autonomic reflexes were involved in the effects. In experiments with animals under ganglionic blockade, an increase in blood pressure, concomitant with an increase in heart rate, was seen 5 min after the infusions ended. Thus, it is likely that the peptide exerts a direct positive chronotropic effect on the feline heart.
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| 13. |
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| 14. |
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| 15. |
- Jernelöv, Arne, et al.
(författare)
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Population management. Ett försök att minska kvicksilverhalten i gädda i Helgasjön
- 1982
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- Föreliggande material tyder på att abborrpopulationen i Helgasjön kunnat minskas till förmån för mört, braxen och björkna, vilket medför att metylkvicksilverhalten i rovfisk som gädda och gös sjunker. Mindre födokonkurrens och snabbare tillväxt bland abborrarna medför sannolikt även sjunkande kvicksilverhalter i dessa. Endast ett fåtal troligen gamla gäddor och gösar ligger nu över svartlistningsgränsen 1 mg/kg. En frilistning av fisket bör kunna ske relativt snart. Projektets målsättning är således nära att uppfyllas. Något års tidsfördröjning har skett beroende på de effekter som några mycket stora årsklasser gös haft på hela Helgasjöns fiskpopulation.
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| 16. |
- Jernelöv, Arne, et al.
(författare)
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Population management - ett försök att minska kvicksilverhalten i gädda i Helgasjön.
- 1980
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- Resultat från fisken 1979 visade oväntat stor andel gös bland rovfisken i Helgasjön. Då gösens föda utgörs till mindre del än gäddans av abborre motverkar den stora göspopulationen och dess predation ansträngningarna att med riktat fiske påverka abborrpopulationen med avseende på individantal och tillväxttakt. Undersökningarna 1980 bekräftar abborrens nyckelroll för kvicksilverhalten i gädda i Helgasjön.
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