UNASSIGNED: @entity519 in @entity1573 embryos increases hematocrit (Hct), blood @entity3612 content, and blood viscosity. The latter may limit @entity3612 transport capacity (OTC) via increased peripheral resistance. Hct increase may result from increased nucleated red blood cell concentration ([RBC]) and mean corpuscular volume (MCV) or reduced plasma volume. We hypothesized changes in Hct, hemoglobin concentration ([Hb]), [RBC] and MCV and their effects on viscosity would reduce OTC. Five experimental treatments that increase Hct were conducted on day 15 embryos: 60min water submergence with 60min recovery in air; exposure to 15% @entity3612 with or without 5% @entity3158 for 24 h with 6 h recovery; or exposure to 10% @entity3612 with or without 5% @entity3158 for 120 min with 120 min recovery. Control Hct, [Hb], [RBC], MCV, and viscosity were approximately 26%, 9g%, 2.0 10(6) L(-1), 130 m(3), and 1.6mPas, respectively. All manipulations increased Hct and blood viscosity without changing blood osmolality (276mmolkg(-1)). Increased viscosity was attributed to increased [RBC] and MCV in submerged embryos, but solely MCV in embryos experiencing 10% @entity3612 regardless of @entity3158 . Blood viscosity in embryos exposed to 15% @entity3612 increased via increased MCV alone, and viscosity was constant during recovery despite increased [RBC]. Consequently, blood viscosity was governed by MCV and [RBC] during submergence, while MCV was the @entity1503 in extrinsic @entity519 with or without @entity2944 . Increased Hct and blood @entity3612 content did not compensate for the effect of increased viscosity on OTC during these challenges.

Dynamics of blood viscosity regulation during XXXX challenges in the @entity1573 embryo ( @entity1573 ).

@entity2944 :: ('MESH:D006935', 'Disease') :: ['hypercapnia'] @entity3158 :: ('D002245', 'Chemical') :: ['CO2'] @entity1503 :: ('MESH:D006402', 'Disease') :: ['strongest determinant of blood viscosity'] @entity1573 :: ('9031', 'Species') :: ['chicken'] @entity519 :: ('MESH:D000860', 'Disease') :: ['Hypoxia', 'hypoxia'] @entity3612 :: ('D013481', 'Chemical') :: ['O2']
@entity519 :: (MESH:D000860,Disease) :: ['hypoxic']
