A Comprative Study On Pectoral Muscles Biophysiology Of Of Three Species Of Migrating Birds To Egypt:

Hanan Hassan Mahmoud

The prime goal in the present study was to deal withbioenergetic sources of some autumnal migrants species on theNorth East coast of Egypt,grounding after their journey over theMediterranean Sea and to estimate the changes in the energysources before and after a replenishing period to continue theirjourney to central Africa. The migratory birds used in thepresent investigation are :( 1 )C.coturnix( 2 )F.atra( 3 )S.turtur( A ) Biometrical comparison :-(TA)LivewCighf-::--- ------There was a building up of weight after migration inC.cotumix and S.turtur.There was also an increase in bothsuperficial and deep pectoral muscle weight in the threemigratory species during the recovery period. A significantincrease was noted among the weight of supracoracoideus muscle ofF.atra and S.turtur throughout the experiment.( 2A ) Wing length :-The mean wing span was measured for all species andpower-weight ratio was calculated ( 18.24 % for C.coturnix ). Thespan loading recorded the highest value in G.domstica.(B) Biochemical analysis:-CTB-yGlycogeii--::------There was a significant increase in glycogen content in bothsuperficial and deep pectoral muscle towards the 2nd week ofcapture in the three migratory species. The increasing glycogenmay be attributed to two reasons :2291- The birds feed during this period and food intake mightregister a rise in glycogen in the tissues.2- The stop of fatty acid oxidation during the postmigrant periodas well as a glycogen resynthesis in muscle.( 2 B ) Glucose:-Serum glucose level was significantly increased after the2nd week of recovery in C,cotumix , F,atra and g,turwr.Thedecrease in plasma glucose during prolonged flying can beattributed to the possible extraction of glucose by thecontracting muscle to provide the carbohydrate source needed forfatty acid oxidation in the muscle.(3 B ) Inorganic phosphorus :-The inorganic phosphorus decreased after the 2nd week ofrecovery in the serum of the three migratory species as well asin the C.livia. On the other hand, the muscular inorganicphosphorus content increased after the 1st week of recovery. Theincrease of serum phosphorus indicated a loss of phosphorus fromthe working muscles during migration.(4 B ) Creatine phosphate :-The highest concentration of C.P was recorded after the 2ndweek of recovery period in the pectoral muscles of the threemigratory species.( 5B ) Adenosine triphosphate ,-Muscular ATP levels in C,coturnix, J:.atra and S.turturincreased after the 2nd week of recovery. The same depletion ofATP and CP in the three migratory species occurred just afterarrival, seems to assume that the long-flying distance is one ofthe factors of significance to stimulate an increased glycolyticactivity.( 6B ) Total lipid :-A significant increase in both of the circulating,superficial and deep pectroal muscle lipid was noticed from 0-day of arrival till the end of the 2nd week after capture in thethree migratory species, suggests the possibility that fatutilization was the main fuel for muscular energy.( 7B ) Cholesterol:-The cholesterol level in the serum of migratory species waselvated throughout the experiment. On the other hand, thecholesterol level in the pectoral muscle in C.cotumix and F.atrawas significantly lowered at the end of the 2nd week of recovery.( 8 B) Triglyceride:-There was a progressive increase in the serum and pectoralmuscle triglyceride content in the three migratory species duringcapture,provide evidence suggesting that during migration,anincrease in the amount of energy derived from fatty acidoxidation .This amount of fatty acid could be accounted for byincreased lipolysis of muscle triglyceride.( 9B) Phospholipids:-The serum and pectoral muscles phospholipids increased afterthe 2nd week of recovery for the migratory species .The decreaseof serum and pectoral muscle phospholipid levels , just afterarrival , could be related to the utilization of fat as fuel formuscular energy.( lOB) Total protein :-There was no significant variation in the total protein levelat 0 _ day of landing and during the two weeks of recovery inthe serum as well as in the pectoral muscles of the migratorybirds . The data do not permit any generalization concerning theprotein metabolism in migratory birds.( llB) fJ- Lipoprotein :-The circulating fJ - lipoprotein was significantly decreasedin both C.coturnix and S.turtur during capture . On tbe otberband ,fJ _ lipoprotein content in tbe deep pectoral muscle of tbethree migratory species, increased after tbe 1 st week ofrecovery.This may be due to after migration , tbe circulating fJ -Lipoprotein attacb to receptors on tbe surface of many cells intbe body and are ingested into tbe cell by endocytosis . Lysosmalenzymes tben break down tbe protein , leaving tbe lipid free intbe cell for incorporation into membranes or otber uses . fJ -lipoprotein increased during flaying because it is tbe principalcariers of cbolesterol in tbe circulation( C ) Body composition ratio :-( IC ) Water content :-There was a decrease in the water content percentage in thesuperficial and deep pectoral muscle in F.atra and S.turturduring capture period. On the other hand in C.cotumix waterpercentage ( in superficial muscle ) increased towards tbe 2ndweek of recovery.Our observation recorded that, the water indexdecreases during capture and has a negative correlation witb fatindex.( 2C ) Lean - dry weight:-The lean - dry weight of the superficial muscle during tbeO-day of recovery was noted to be higher than after two weeks inbotb of C.cotumix and S.turtur ..( D ) Enzymes :-( 1D ) Glucose - 6 - phoSjlbate debydroiCnase .-The estimated G6pDH in tbe serum as well as in tbe pectoralmuscles of the three migratory species increased at the end ofthe 2nd week of recovery. So that there was a probability ofcharing of G6PO in glycolysis by an indirect way·( E ).Hormones : -( 1..B )Jnsulin..: -The circulating and pancreatic tissue levels of insulin inthe three migratory species were significantly increased at theend of the 2nd week of recovery. The lower of insulin levelduring migration may be attributed to prevent the lipidsynthesis.( 2 E ) GlucagonThe circulating andsignificantly decreasedcapture. The elevationindicate that glucagonfatty acid synthesis.pancreatic tissue levels of glucagon werein the three migratory species duringof glucagon level during migrationaccelerates FFA release and inhibits( G LHistochemistry( I G ) Fat: -The pectoral muscles showed an increase in intracellularlipid content in all migratory species during the recoveryperiod ( specially in the superficial muscles ). The fat bodiesare enlarged after recovery without increment in the number ofcells, with relative increment of cell diameter as a result ofincreased fat deposition.<”2 G ) Succinic dehydroienaseA low SOH activity was observed in the muscles at 0 - day ofarrival in the three migratory species. The activity of SOHincreased with recovery period ( specially in the superficialmuscles ).Also, the red fibers indicated a high SOH activity; incontrast, the white fibers were the lowest in activity. This maybe related to the fact that, red muscle, which is capable ofprolonged activity, relies on a high capacity for oxidativemetabolism.( 3 G ) GlycogenThere was an increase in glycogen concentration in bothsuperficial and deep pectoral muscles after the 2nd week ofrecovery in the three migratory species ( specially in the deepmuscles ).( HLMorphometric TechniqueAnalysis of cross section areasFibre types can be classified into white, intermediate andred muscle fibers.