ABSTRACT
A retrospective study was undertaken to determine the prevalence of hypoalbuminemia in dogs with hypoadrenocorticism. During a 94-month interval, 17 of 44 dogs (38.6%) with hypoadrenocorticism were found to have hypoalbuminemia. When compared to all dogs with hypoalbuminemia (9.8%) observed in the hospital population during this same interval, there appeared to be a significant association between canine adrenocortical insufficiency and hypoalbuminemia. The pathogenesis of the hypoalbuminemia in this study is speculative; possible mechanisms include gastrointestinal blood loss, protein-losing enteropathy, malassimilation, or decreased albumin synthesis. Renal protein loss was not supported by routine urinalysis findings.
Subject(s)
Adrenal Insufficiency/veterinary , Dog Diseases/etiology , Serum Albumin/deficiency , Adrenal Insufficiency/blood , Adrenal Insufficiency/etiology , Animals , Blood Chemical Analysis , Dog Diseases/blood , Dogs , Female , Male , Prevalence , Retrospective StudiesABSTRACT
This work examined the noradrenaline content of brown adipose tissue, the metabolic response to endogenous noradrenaline released during tyramine infusion, and the innervation of brown fat at the electron microscopic level in the young rabbit. The noradrenaline content (ng/g) of the interscapular and cervical fat deposits ranged from 256 +/- 51 to 343 +/- 59 and 399 +/- 18 to 694 +/- 92, respectively, in four groups of rabbits (1-2, 7-8, 12-13, and 25-27 days of age). There was considerable variation amongst animals in each age group, but no evidence of a major increase or decrease in noradrenaline content during the first 4 weeks of life. Intravenous infusion of tyramine (100 micrograms X kg-1 X min-1) increased plasma noradrenaline concentration, oxygen consumption, and blood flow to brown fat. Thus noradrenaline released from endogenous sites, as well as injected noradrenaline, will initiate the thermogenic response of brown fat. Ultrastructurally, unmyelinated axons that were not organized in a fascicle were observed adjacent to the adipocytes in the late gestation fetus. By 1 week of age of axons were surrounded by Schwann cell cytoplasm which formed a fascicle. However, no evidence of myelination was found up to 21 days of age. Collectively, the data indicate that the brown adipocyte is fully responsive at 1-2 days of age even though myelination of the nerves is incomplete, and that the incomplete development of the sympathetic nerves at birth is not a factor in the synthesis of noradrenaline in the very young rabbit. In addition, brown fat of the newborn rabbit is not as thermogenically active as the brown fat of the cold-acclimated rat.
