| 1. |
- Holmgren, Susanne, 1946, et al.
(författare)
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The neuroendocrine regulation of gut function
- 2009
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Ingår i: Fish Physiology Volume 28: Fish Neuroendocrinology (Eds Nicholas J. Bernier, Geln Van Der Kraak, Anthony P. Farrel, Colin J. Brauner). - : Academic Press. - 9780123746313 ; , s. 467-512
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Bokkapitel (övrigt vetenskapligt/konstnärligt)
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| 2. |
- Krönström, Jenny, 1978, et al.
(författare)
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Involvement of contractile elements in control of bioluminescence in Northern krill, Meganyctiphanes norvegica (M. Sars).
- 2009
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Ingår i: Cell and tissue research. - : Springer Science and Business Media LLC. - 1432-0878 .- 0302-766X. ; 336:2, s. 299-308
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Tidskriftsartikel (refereegranskat)abstract
- Inside the light organs of the bioluminescent (light-producing) crustacean Meganyctiphanes norvegica (krill), numerous capillaries drain haemolymph into the light-producing structure (lantern). We have investigated the arrangement and function of filamentous material found around the opening of the capillaries. These have been suggested to work as sphincters, controlling the haemolymph (i.e. oxygen) supply to the lantern and thereby the production of light. Electron microscopy shows that the filamentous material consists of thick and thin muscle filaments arranged in perpendicular blocks around the opening of each capillary. The actin probe rhodamine phalloidin has revealed that one component is filamentous actin. Clusters of vesicle-dense nerve profiles surround the cells containing filamentous material and antibodies against 5-hydroxytryptamine (5-HT) reveal that 5-HT containing nerves lead to the filamentous area. When exposed to the muscle-relaxing substances papaverine and verapamil, krill respond with luminescence, suggesting that the sphincter structures are functionally involved in the control of light production. Treatment with the muscle-contracting drugs Bay K8544 and thapsigargin gives no light response. Thus, 5-HT stimulates light production in krill; however, a combination of 5-HT and the muscle-relaxing drugs or Bay K8544 potentiates the effect of 5-HT. Thapsigargin quenches the response to 5-HT. Our results corroborate speculations of earlier authors who have suggested that the sphincter structures are of a muscular nature and important in controlling light production in krill. However, other parameters in addition to the oxygen supply to the lantern are involved in controlling bioluminescence in the light organs of M. norvegica.
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| 3. |
- Shahbazi, Fatemeh, et al.
(författare)
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Cod CGRP and tachykinins in coeliac artery innervation of the Atlantic cod, Gadus morhua: presence and vasoactivity.
- 2009
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Ingår i: Fish physiology and biochemistry. - : Springer Science and Business Media LLC. - 1573-5168 .- 0920-1742. ; 35:3, s. 369-76
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Tidskriftsartikel (refereegranskat)abstract
- The presence and vasoactive effects of native calcitonin gene-related peptide (CGRP), substance P (SP), and neurokinin A (NKA) were studied on isolated small branches of the coeliac artery from Atlantic cod, Gadus morhua, using immunohistochemistry and myograph recordings, respectively. Immunohistochemistry revealed nerve fibers containing CGRP- and SP/NKA-like material running along the wall of the arteries. CGRP induced vasorelaxation of precontracted arteries with a pD(2) value of 8.54 +/- 0.17. Relaxation to CGRP (10(-8) M) was unaffected by L-NAME (3 x 10(-4) M) and indomethacin (10(-6) M) suggesting no involvement of nitric oxide or prostaglandins in the CGRP-induced relaxation. SP and NKA (from 10(-10) to 3 x 10(-7) M) contracted the unstimulated arteries at concentrations from 10(-8) M and above in 42% and 33%, respectively, of the vessels. It is concluded that the innervation of the cod celiac artery includes nerves expressing CGRP-like and tachykinin-like material, and that a vasodilatory response to CGRP is highly conserved amongst vertebrates while the response to tachykinins is more variable.
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