Morphology of the pattern of branching of the aortic arch (Arcus aortae) in Syrian hamsters (Mesocricetus auratus)

The branching patterns of the aortic arches of 28 adult male and female Syrian hamsters (SH) were thoroughly examined under a stereomicroscope for the first time by using latex injection and corrosion casting to determine their general arrangements and morphological variations as well as their differences and similarities to other rodents and rabbits. Three major arteries, namely, the brachiocephalic trunk (BC), left common carotid artery (CC) and left subclavian artery (SA), originating from the aortic arch (AR), were uniformly noted in SH. The BC was consistently divided into the right SA and the right CA. SA in SH normally releases the internal thoracic, deep cervical, dorsal scapular, vertebral, superficial cervical and supreme intercostal arteries. The costocervical trunk typically consisted of supreme intercostal and internal thoracic arteries and a common trunk for dorsal scapular and deep cervical arteries. To comprehend the comparative morphology of the pattern of branching of AR more completely, our results were compared with previous studies in rodents and rabbits. (1) The general morphology of the great arteries from AR in SH was similar to that in mole rats, rats, mice, porcupines, and gerbils but was essentially different from that in rabbits, guinea pigs, red squirrels, ground squirrels, pacas and chinchillas. (2) The typical pattern of the branching of the subclavian arteries in SH was similar to that in guinea pigs, rats, and rabbits but was different from that of the reported rodents regardless of the origins of the bronchoesophageal and internal thoracic arteries and the composition of the costocervical trunk.