A doc­tor has launched an in­ves­ti­ga­t­ion in­to what he calls the “re­mark­a­ble” abil­ity of dol­phins to heal from atro­cious wounds, say­ing hu­mans may ben­e­fit from the re­search.

With no ap­par­ent med­i­cal care, the finned mam­mals seem­ingly shrug off—and to­tally re­cov­er from—shark bites that look shock­ingly bad to a per­son, ac­cord­ing to the phy­si­cian, Mi­chael Zas­loff. “Com­pa­ra­ble in­ju­ries in hu­mans would be fa­tal,” said Zas­loff, of George­town Uni­vers­ity Med­i­cal Cen­ter in Wash­ing­ton, D.C., adding that dol­phins show lit­tle sign of pain from the wounds.

“Much about the dol­phin’s heal­ing pro­cess re­mains un­re­ported and poorly doc­u­ment­ed,” he went on. “How does the dol­phin not bleed to death af­ter a shark bite? How is it that dol­phins ap­pear not to suf­fer sig­nif­i­cant pain? What pre­vents in­fec­tion of a sig­nif­i­cant in­ju­ry? And how can a deep, gap­ing wound heal in such a way that the an­i­mal’s body con­tour is re­stored? 

Za­sloff, who has pre­vi­ously iden­ti­fied an­ti­mi­cro­bi­al com­pounds in the skin of frogs and in the dog­fish shark, re­ported his re­cent re­search in a let­ter pub­lished in the July 21 is­sue of the Jour­nal of In­ves­ti­ga­tive Der­ma­tol­o­gy. He in­ter­viewed dol­phin han­dlers and ma­rine bi­ol­o­gists from around the world and re­viewed the lim­it­ed lit­er­a­ture avail­a­ble about dol­phin heal­ing.

Za­sloff pro­poses that dol­phins may lim­it blood loss by div­ing deep af­ter an in­ju­ry, which di­verts blood away from out­er ar­eas of the body and to­ward the cen­ter. As for the ap­par­ent in­dif­fer­ence to pain, it “clearly rep­re­sents an adapta­t­ion fa­vor­a­ble for sur­vival,” he wrote in the let­ter, but how the feat is man­aged is un­known.

How the an­i­mal keeps in­fec­tion at bay may be less of a mys­tery, he said, pro­pos­ing that the an­i­mal’s blub­ber holds the key. Blub­ber and its make­up have been stud­ied ex­ten­sively be­cause it ac­cu­mu­lates many man-made pol­lu­tants, Zas­loff said. It’s thus well doc­u­mented that blub­ber al­so con­tains nat­u­ral an­ti­bi­otics called orga­no­ha­lo­gens. Probably “the dol­phin stores its own an­ti­mi­cro­bi­al com­pound,” Zas­loff pre­dicts. “This ac­tion could con­trol and pre­vent mi­cro­bi­al in­fec­tion while at the same time pre­vent­ing de­com­po­si­tion around the an­i­mal’s in­ju­ry.”

Za­sloff al­so ex­plored the abil­ity of the dol­phin’s wound to heal in a way that re­stores the body con­tour. He said the dol­phin’s heal­ing abil­ity is less like hu­man heal­ing and more like re­genera­t­ion. “The re­pair of a gap­ing wound to an ap­pearance that is near nor­mal re­quires the abil­ity of the in­jured an­i­mal to knit newly formed tis­sues with the ex­ist­ing fab­ric of adipocytes [fat cells], col­la­gen and elas­tic fibers,” he wrote. “The dol­phin’s heal­ing is si­m­i­lar to how mam­ma­li­an fe­tus­es are able to heal in the wom­b.”

Brent Whit­a­ker, dep­u­ty ex­ec­u­tive di­rec­tor for bi­o­log­i­cal pro­grams at the Na­tional Aquar­i­um in Bal­ti­more, called Zas­loff’s let­ter “thought pro­vok­ing.” Zas­loff con­sulted with Whit­a­ker as part of his re­search.

“It makes sense that the der­mal tis­sues of the dol­phins would evolve mech­a­nisms to pro­tect them from the mi­crobes ev­er pre­s­ent in the wa­ter in which these an­i­mals live,” Whit­a­ker said. “Other aquat­ic an­i­mals have de­vel­oped pro­tective strate­gies that al­low them to cope with wa­ter-borne mi­croflo­ra,” or pathogens. Zas­loff’s let­ter “sug­gests a un­ique and in­tri­guing hy­poth­e­sis which may beg­in to ex­plain how dol­phins, and per­haps oth­er cetaceans, sur­vive sig­nif­i­cant soft-tis­sue wounds in the wild with­out the aid of an­ti­bi­otics or clin­i­cal care,” he added.

“It is very clear from work­ing with ma­rine mam­mals that the abil­ity to heal is ‘en­hanced’ from what we see with ter­res­tri­al mam­mals,” said Leigh Ann Clay­ton, di­rec­tor of the De­part­ment of An­i­mal Health at the Na­tional Aquar­i­um, who al­so ad­vised Zas­loff. “Zas­loff pro­poses some fas­ci­nat­ing mech­a­nisms of ac­tion in heal­ing. It is ex­cit­ing to beg­in ex­plor­ing these mech­a­nisms more com­plete­ly.”

In his let­ter, Zas­loff pre­s­ents the case his­to­ries of two shark-bitten dol­phins, Nari and Ech­o, at the Tan­ga­looma Wild Dol­phin Re­sort in More­ton Is­land, Aus­tral­ia. The re­ports doc­u­ment the heal­ing pro­cess of the dol­phins with pho­tos to el­o­quently dem­on­strate how and how quickly two dol­phins heal from sev­ere shark in­ju­ries.

“The Tan­ga­looma dol­phin care team is con­tin­u­ously as­tounded at the remarka­ble nat­u­ral abil­ity of the dol­phins that vis­it us, in over­com­ing sev­ere shark bite in­ju­ries with what seems to be in­dif­fer­ence,” said Trev­or Has­sard, di­rec­tor of Tan­ga­looma. “We learn so much from the lives of oth­er an­i­mals. Per­haps Zas­loff’s con­tri­bu­tion will br­ing the dol­phin’s remarka­ble heal­ing ca­pa­ci­ties to the at­ten­tion of the med­i­cal re­search com­mun­ity.”

“My hope is this work will stim­u­late re­search that will ben­e­fit hu­mans,” said Zas­loff. “I feel rea­sonably cer­tain that with­in this an­i­mal’s heal­ing wounds we will find nov­el an­ti­mi­cro­bi­al agents as well as po­tent an­al­ge­sic com­pounds.”

http://www.world-science.net/othernews/110721_dolphin.htm