{"id":3748,"date":"2012-06-15T06:00:25","date_gmt":"2012-06-15T06:00:25","guid":{"rendered":"http:\/\/esc-sec.ca\/wp\/2012\/06\/15\/physiology-friday-nitric-oxide-causes-a-sticky-situation\/"},"modified":"2019-11-14T21:47:42","modified_gmt":"2019-11-14T21:47:42","slug":"physiology-friday-nitric-oxide-causes-a-sticky-situation","status":"publish","type":"post","link":"https:\/\/esc-sec.ca\/fr\/2012\/06\/15\/physiology-friday-nitric-oxide-causes-a-sticky-situation\/","title":{"rendered":"Physiology Friday – Nitric oxide causes a sticky situation"},"content":{"rendered":"

Physiology Friday is a monthly column by UWO PhD candidate Katie Marshall<\/a> and will feature new Canadian research on insect physiology.<\/strong><\/p>\n

——————<\/p>\n

Nitric oxide (NO) is usually overshadowed in fame by its more famous cousin laughing gas, but it\u2019s difficult to think of many simple molecules that have such a variety of important biological functions.\u00a0 While NO only lasts a few seconds in the free gaseous state in the blood, it has been implicated in processes that involve everything from immune function to neurotransmission.\u00a0 One important role for NO is in the cardiac system, where it functions as a vasodilator and in vertebrates it slows heart rate, while in insects it has the opposite effect.<\/p>\n

\"Stick<\/a>

Baculum extradentatum photo by Sara da Silva<\/p><\/div>\n

Most of the research about the physiological functions of NO has focused on vertebrates, but recent work published in the journal of Cellular Signalling<\/em> by graduate student Sara da Silva and her postdoctoral fellow mentor Rosa da Silva in the lab of Angela Lange (University of Toronto Mississauga)<\/a>, has shown that, unlike other insects, the Vietnamese stick insect Baculum extradentatum<\/em> can respond to NO like a vertebrate.<\/p>\n

\u201cOur initial research interests in cardiac physiology were influenced by earlier work indicating that stick insect hearts are innervated and can be modulated by endogenous chemicals [like NO],\u201d says study director and University of Toronto Biology professor Angela Lange.\u00a0 \u201cIt is for this reason that we chose this understudied organism, which contains a simplified cardiovascular system that can be considered a model for work on other cardiac systems.\u201d<\/p>\n

The researchers first attempted to find the natural source of NO in the stick insect by removing hemolymph (blood) samples and staining for the presence of an enzyme that produces NO.\u00a0 Then they examined the effects of NO on heart rate by dissecting the dorsal vessel out and maintaining it in a Petri dish with physiological saline.\u00a0 They could measure heart rate through the placement of electrodes on either side of the dissected heart, and monitor the effects of various chemicals on the cardiac activity of the stick insect. \u00a0\u00a0They also could examine whether heart rate was mediated by the central nervous system by leaving the nervous system attached or not.<\/p>\n

\"insect<\/a>

The effects of nitric oxide on the heart rate of B. extradentatum. Figure 3 from da Silva et al. 2012<\/p><\/div>\n

They found that the hemocytes (blood cells) of the stick insect were producing an enzyme that was similar to the enzyme other animals use to produce NO. \u00a0In addition, the more of a chemical called MAHMA-NONOate (which produces NO) they added, the slower the stick insect hearts beat.\u00a0 This surprising effect was completely opposite to what had been found in other insects and was more like the response of the vertebrate heart.<\/p>\n

\u201cInsects have evolved different strategies depending upon life history, and have co-opted different messenger systems for this success,\u201d says study author da Silva. \u201cWe need to understand the full ecology of all species to finally appreciate the factors involved.\u201d<\/p>\n

Using the same setup, they also tested other components of a system of compounds that they thought might be involved in the pathway that produces NO that leads to decreased heart rate in B. extradentatum<\/em>.\u00a0 They believe that NO is produced in the hemocytes, travels to the wall of the heart, and then leads to the production of a messenger molecule that decreases heart rate.<\/p>\n

\"Schematic<\/a>

Schematic diagram of the proposed regulation of cardiac activity in B. extradentatum by the gaseous signaling molecule, nitric oxide (NO). Figure 7 from da Silva et al. 2012.<\/p><\/div>\n

\u201cThis study further emphasizes the evolutionary links between the physiological processes of vertebrate and invertebrate systems,\u201d says da Silva. \u201cOur findings suggest that signaling molecules (such as NO) common to both types of organisms can have similar effects on cardiac activity.\u00a0 These novel findings demonstrate that the study of vertebrate systems can be complemented with studies in model invertebrate organisms.\u201d<\/p>\n

—————————-
\nda Silva, R., da Silva, S.R. & Lange, A.B. (2012). The regulation of cardiac activity by nitric oxide (NO) in the Vietnamese stick insect, Baculum extradentatum, Cellular Signalling, 24<\/span> (6) 1350. DOI: 10.1016\/j.cellsig.2012.01.010<\/a><\/span><\/p>\n","protected":false},"excerpt":{"rendered":"

Physiology Friday is a monthly column by UWO PhD candidate Katie Marshall and will feature new Canadian research on insect physiology. —————— Nitric oxide (NO) is usually overshadowed in fame by its more famous cousin laughing gas, but it\u2019s difficult to think of many simple molecules that have such a variety of important biological functions.\u00a0 […]<\/p>\n","protected":false},"author":6,"featured_media":0,"comment_status":"closed","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_jetpack_memberships_contains_paid_content":false,"footnotes":""},"categories":[471,473,513,550],"tags":[886,519,826,887],"class_list":["post-3748","post","type-post","status-publish","format-standard","hentry","category-academic-fr","category-blog-fr","category-research-fr","category-research-blogging-fr","tag-phasmatodea-fr","tag-physiology-fr","tag-physiology-fridays-fr","tag-stick-insect-fr"],"jetpack_featured_media_url":"","views":"","jetpack_sharing_enabled":true,"_links":{"self":[{"href":"https:\/\/esc-sec.ca\/fr\/wp-json\/wp\/v2\/posts\/3748","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/esc-sec.ca\/fr\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/esc-sec.ca\/fr\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/esc-sec.ca\/fr\/wp-json\/wp\/v2\/users\/6"}],"replies":[{"embeddable":true,"href":"https:\/\/esc-sec.ca\/fr\/wp-json\/wp\/v2\/comments?post=3748"}],"version-history":[{"count":1,"href":"https:\/\/esc-sec.ca\/fr\/wp-json\/wp\/v2\/posts\/3748\/revisions"}],"predecessor-version":[{"id":5484,"href":"https:\/\/esc-sec.ca\/fr\/wp-json\/wp\/v2\/posts\/3748\/revisions\/5484"}],"wp:attachment":[{"href":"https:\/\/esc-sec.ca\/fr\/wp-json\/wp\/v2\/media?parent=3748"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/esc-sec.ca\/fr\/wp-json\/wp\/v2\/categories?post=3748"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/esc-sec.ca\/fr\/wp-json\/wp\/v2\/tags?post=3748"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}