Effects of both the emotional behavior and feeding conditions on the circulating plasma volume and plasma glucose levels in cats

Influence of hypothalamically induced emotional behavior on the circulating plasma volume, plasma levels of glucose, epinephrine (E), norepinephrine (NE), dopamine (DA) and cortisol were examined in awake cats under both fasted and fed conditions. Restlessness was evoked intermittently for 6 h by electrical stimulation of the anteromedial hypothalamus (AMH). Blood was sampled immediately before, 1 h after and 6 h after the start of stimulation. Changes in the plasma volume was calculated by changes of hemoglobin (Hb) and hematocrit (Ht). As the control group, another 7 cats with electrodes implanted but unstimulated were identically treated under both fasted and fed conditions. Both E and glucose levels in restlessness group once markedly increased after 1 h and then tended to decrease after 6 h, whereas NE levels in restlessness group increased after 1 h and further increased after 6 h, whether cats were fasted or fed. DA levels increased under the fasted condition of restlessness. The cortisol level markedly increased in both fasted and fed restlessness groups. The plasma volume in control group increased under the fed condition, while in restlessness group it decreased remarkably and tended to decrease more in a fasted state than in a fed state. These results indicated that AMH induced restlessness elicited marked sympatho-adrenal activation, hyperglycemia and hemoconcentration, whether cats were fasted or fed. Relationship among such responses, and the difference in responses between fasted and fed conditions were also discussed in the paper.