Functional and neurometabolic asymmetry in SHR and WKY rats following vasoactive treatments

Abstract

A lateralized distribution of neuropeptidase activities in the frontal cortex of normotensive and hypertensive rats has been described depending on the use of some vasoactive drugs and linked to certain mood disorders. Asymmetrical neuroperipheral connections involving neuropeptidases from the left or right hemisphere and aminopeptidases from the heart or plasma have been suggested to play a role in this asymmetry. We hypothesize that such asymmetries could be extended to the connection between the brain and physiologic parameters and metabolic factors from plasma and urine. To assess this hypothesis, we analyzed the possible correlation between neuropeptidases from the left and right frontal cortex with peripheral parameters in normotensive (Wistar Kyoto [WKY]) rats and hypertensive rats (spontaneously hypertensive rats [SHR]) untreated or treated with vasoactive drugs such as captopril, propranolol and L-nitro-arginine methyl ester. Neuropeptidase activities from the frontal cortex were analyzed fluorometrically using arylamide derivatives as substrates. Physiological parameters and metabolic factors from plasma and urine were determined using routine laboratory techniques. Vasoactive drug treatments differentially modified the asymmetrical neuroperipheral pattern by changing the predominance of the correlations between peripheral parameters and central neuropeptidase activities of the left and right frontal cortex. The response pattern also differed between SHR and WKY rats. These results support an asymmetric integrative function of the organism and suggest the possibility of a different neurometabolic response coupled to particular mood disorders, depending on the selected vasoactive drug.

The Type of Fat in the Diet Influences the Behavior and the Relationship Between Cystinyl and Alanyl Aminopeptidase Activities in Frontal Cortex, Liver, and Plasma

“…From brains, the frontal lobes (11.20 mm anterior to the interaural line) were dissected according to the stereotaxic atlas of Paxinos and Watson (1998). Plasma was isolated by centrifugation of blood samples for 10 min at 2,000 g using heparin as an anticoagulant and stored at −20 • C. TCH and GLU were determined colourimetrically in plasma using kits supplied, respectively, by Sigma (St Louis, MO) and Spinreact (Girona, Spain) and expressed as mg/dL (Segarra et al, 2019b). In order to avoid its possible influence on the studied factors such as CysAP (Habtemichael et al, 2015), fasting conditions were not included in the study.…”

“…Tissues do not function as independent compartments: they interact among each other to offer an integrated response to changes in the internal and/or external environment (Samdani et al, 2015;Segarra et al, 2019b). If the level of activity of each enzyme in each tissue can be differentially modified depending on the type of diet, a possible interaction between such intra and inter-tissue activities could also be modified.…”

Is there a link between depression, neurochemical asymmetry and cardiovascular function?

“…Less suspicious than Broca, Bernard said: “The heart and the brain are therefore in a solidarity of the most intimate reciprocal actions, which multiply and tighten even more as the organism becomes more developed and more sophisticated... The expression of our feelings is made by an exchange between the heart and the brain, the two most perfect gears of the living machine...” Furthermore, various results have shown that this neurovisceral integration can function asymmetrically, from the input of sensory information [17] to the expression of physiological functions and the generation of metabolic products [3] , [18] – [20] .…”

“…In basis to these results, the authors postulated that such asymmetrical brain-cardiovascular functional connection could be part of a global response of the organism that involves physiological parameters as well as metabolic factors in body fluids such as plasma or urine, framed within a global concept of asymmetrical neurovisceral integration [3] . To analyze this hypothesis, they studied the possible correlations between neuropeptidases of the left and right frontal cortices with physiological parameters such as water intake, diuresis or aqueous balance, metabolic factors such as lipids, nitric oxide and plasma glucose, as well as nitric oxide, proteins and creatinine in urine of normotensive and hypertensive animals treated or not with captopril, propranolol or L-NAME.…”

“…Compendium of the results obtained by Segarra et al [3] in which the correlations obtained between the left or right frontal cortex and the various physiological and metabolic parameters, considered as a whole, in normotensive and hypertensive animals are reflected in a simplified way. The color of the arrows indicates the treatment the animals underwent: blue (untreated controls), green (captopril-treated), gray (propranolol-treated), red (L-NAME-treated).…”