title: Microsphere studies of bullfrog central vascular shunts during diving and breathing in air.
abstract: Bidirectional central vascular shunts were measured during diving and breathing in air in unanesthetized bullfrogs by using pulmonary trapping of 38 mu mean diameter radionuclide-labelled microspheres. Six animals studied during diving exhibited a strong overall right-to-left shunting pattern comprised of both a predominant (68% mean) right-to-left shunt and a weak (23%) left-to-right countershunt. Five animals with access to air showed a variety of distribution patterns, including predominant shunts in the left-to-right (1 animal) and right-to-left (1 animal) directions, nearly complete mixing (2 animals) and separation of systemic and pulmonary venous returns (1 animal).
mesh_terms: D000818:Animals; D001001:Anura; D001158:Arteries / Q000502:physiology; D004242:Diving; D008863:Microspheres; D010100:Oxygen / Q000097:blood*; D011892:Rana catesbeiana / Q000502:physiology*; D012119:Respiration; D014680:Veins / Q000502:physiology
chemical_list: D010100:Oxygen