Dietary protein and carbohydrate effects on blood parameters related to stress in cat

Plasma dopamine in workers exposed to urban stressor

The aim of this study is to evaluate if the occupational exposure to urban stressor could cause alterations in dopamine (DA) plasma levels and related diseases in traffic police officers compared to a control group. After excluding subjects with principal confounding factors, 306 traffic police officers (139 female and 167 male) and 301 controls (134 female and 167 male) were included in the study. In traffic police officers, mean DA values were significantly higher compared with controls (P = 0.006 and P = 0.000 in male and female, respectively). The distribution of DA values in traffic police officers and controls was significant (P = 0.000 and P = 0.000 in male and female, respectively). The number of male traffic police officers with a positive response to the questionnaire's items concerning anxiety, depression and panic attacks was higher than controls, though not significant (7.2% traffic police officers versus 4.2% controls). This difference was also not significant in female traffic police officers compared with controls. According to our previous researches on other neuro-immune-endocrine parameters, DA could be used as an early biological marker, valuable for the group to be employed in occupational sets, even before the onset of pathology.

Heritable Components of Feline Hematology, Clinical Chemistry, and Acid–Base Profiles

Four erythrocyte variables (erythrocyte count, hemoglobin, mean cell volume, packed cell volume), 14 serum variables (alanine transferase, albumin, alkaline phosphatase, calcium, chloride, cholesterol, creatinine, glucose, phosphorus, potassium, sodium, total protein, triglycerides, urea nitrogen), and 7 venous acid-base variables (base excess, bicarbonate, carbon dioxide partial pressure, oxygen partial pressure, oxygen saturation, pH, and total carbon dioxide) were evaluated for heritability in domestic cats (Felis catus). Values used for individual cats were expressed as the mean over all lifetime measurements, using 444-530 animals for clinical chemistry, 629 animals for acid-base, and 564 animals for erythrocyte metrics. Gender and age at death (where applicable) also were evaluated for correlation with variables. Heritabilities for clinical chemistry, acid-base, and erythrocyte variables ranged, respectively, from 0.13 to 0.78, from 0.23 to 0.59, and from 0.41 to 0.69 (P < 0.05). This result indicates that serum variability has a genetic basis and is segregating in this feline population. These findings may have important implications in both research and clinical medicine.

Dietary calcium supplementation and dopamine-beta-hydroxylase in spontaneously hypertensive rats

Spontaneously hypertensive 4-week-old male rats were fed, before and after the onset of hypertension, with either commercial chow (control) or commercial chow combined with different forms of milk proteins with or without calcium supplementation. After 40 weeks, rats were still hypertensive, and dopamine-beta-hydroxylase enzyme activity measured simultaneously in serum and adrenal was found to be higher than in the controls. The enzyme activity in rats fed diets with milk proteins was increased significantly in both serum and adrenal compared with the control, and such enhancement was significantly higher than that observed in animals fed the commercial diet supplemented with calcium (1.2%), suggesting that dietary calcium intake associated with dietary protein of high digestibility, such as casein, potentiates the endogenous mechanisms regulating the homeostasis of calcium more than calcium supplementation itself. Moreover, the selective and additive effect of diets supplemented with milk proteins and calcium on adrenal enzyme activity clearly suggests a relationship between cardiovascular diseases involving the genesis of hypertension and stress mechanisms through the hypothalamo-pituitary adreno-sympathetic axis.

Comparative study of biochemical parameters and kinetic properties of dopamine-beta-hydroxylase activity from cat and rat adrenals

The specific adrenal dopamine-beta-hydroxylase activity measured in cat and rat was: (1) two times higher in cat than in rat; (2) significantly enhanced by ascorbate (up to 5 mM) that acts as a major activator; (3) differently affected by exogenous copper added to the incubation medium, leading to a decrease with large concentrations; and (4) similar, according to the kinetic parameters, thereby demonstrating a greater affinity for ascorbate than for tyramine.