Gastrointestinal and renal responses to variable water intake in whitebellied sunbirds and New Holland honeyeaters.

摘要: Summary Nectarivores face a constant challenge in terms of water balance, experiencing loading or dehydration when switching between food plants feeding and fasting. To understand how whitebellied sunbirds New Holland honeyeaters meet the challenges varying preformed load, we used elimination Intramuscular-injected [ 14 C]-L-glucose 3 H 2 O to quantify intestinal renal handling on diets sugar concentration. Both showed significant modulation absorption, allowing excess be shunted through intestine dilute diets. Despite reducing their fractional both species linear increases flux body turnover as intake increased (both afternoon morning), suggesting that absorption was not sufficient completely offset dietary loads. In species, glomerular filtration rate (GFR) independent gain (but higher for afternoon), reabsorption (measured afternoon). During natural overnight fast, arrested whole kidney function. Evaporative loss variable but correlated with gain. appear modulate an important component regulation help deal massive Shutting down GFR during fast is another way saving energy osmoregulatory Birds maintain osmotic balance markedly load by excretion kidneys.