High-fat diet changes the behavioural and hormonal responses to water deprivation in male Wistar rats

Author(s)

Dos-Santos, Raoni Conceicao ; Ishioka, Gabriel ; Cognuck, Susana Quiros ; Mantovani, Milene ; Caliman, Izabela Facco ; Kagohara Elias, Lucila Leico ; Antunes-Rodrigues, Jose

• Document type: Journal article
• Source: Experimental Physiology; v. 107, n. 12, p. 13-pg., 2022-10-12.

Abstract

New Findings What is the central question of this study? What is the effect of an obesogenic diet on the control of hydromineral balance in rats? What is the main finding and its importance? The results showed that, when dehydrated, rats fed a high-fat diet drink less water than their control-diet-fed counterparts. Changes in aquaporin-7 and peroxisome proliferator-activated receptor alpha expression in the white adipose tissue might be involved. High-fat diet (HFD) increases fat accumulation, glycaemia and blood triglycerides and is used as a model to study obesity. Besides the metabolic changes, obesity likely affects water intake. We assessed the effects of HFD on behavioural and hormonal responses to water deprivation. Additionally, we measured if the adipose tissue is differentially affected by water deprivation in control and HFD-fed rats. HFD rats showed a decreased basal water intake when compared to control-fed rats. When subjected to 48 h of water deprivation, as expected, both control and HFD rats drank more water than the hydrated rats. However, the increase in water intake was lessened in HFD dehydrated rats. Similarly, the increase in haematocrit in dehydrated rats was less pronounced in HFD dehydrated rats. These results suggest that HFD diminishes drinking behaviour. White adipose tissue weight, glycaemia and plasma glycerol concentration were increased in HFD rats; however, after 48 h of water deprivation, these parameters were significantly decreased in dehydrated HFD rats, when compared to controls. The increase in adipose tissue caused by HFD may mitigate the effects of dehydration, possibly through the increased production of metabolic water caused by lipolysis in the adipocytes. Oxytocin possibly mediates the lipolytic response, since both its secretion and receptor expression are affected by dehydration in both control and HFD rats, which suggests that oxytocin signalling is maintained in these conditions. Changes in mediators of lipolysis, such as aquaporin-7 and peroxisome proliferator-activated receptor alpha, might contribute to the different effects observed in control and HFD rats. (AU)

• FAPESP's process: 13/09799-1 - Energy balance and body fluid homeostasis control: from cells to the physiological systems
• Grantee: José Antunes Rodrigues
• Support Opportunities: Research Projects - Thematic Grants
• FAPESP's process: 16/20132-7 - Neuroendocrine control of hydromineral balance in obese rats
• Grantee: Gabriel de Andrade Ishioka
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• FAPESP's process: 18/18071-5 - Hydroelectrolytic and energy homeostasis: from cellular metabolism to endocrine systems in different phases of development
• Grantee: Lucila Leico Kagohara Elias
• Support Opportunities: Research Projects - Thematic Grants
• FAPESP's process: 19/01260-2 - The role of hypothalamic paraventricular nucleus GABAergic and CRHergic neurons on ghrelin's effect on energy metabolism
• Grantee: Raoni da Conceição dos Santos
• Support Opportunities: Scholarships in Brazil - Post-Doctoral