Impaired hypotensive effects of centrally acting oxytocin in SHR and WKY rats exposed to chronic mild stress
Autor: | Olena Wojno, Agnieszka Wsol, Agnieszka Cudnoch-Jędrzejewska, Robert Wrzesień, Ewa Szczepanska-Sadowska, Liana Puchalska |
---|---|
Rok vydání: | 2020 |
Předmět: |
Male
0301 basic medicine medicine.medical_specialty Time Factors Physiology Blood Pressure Oxytocin Rats Inbred WKY Random Allocation 03 medical and health sciences 0302 clinical medicine Heart Rate Stress Physiological Mild stress Rats Inbred SHR health services administration Physiology (medical) Internal medicine medicine Animals Chronic stress health care economics and organizations business.industry Infusion Pumps Implantable Rats Infusions Intraventricular 030104 developmental biology Endocrinology Blood pressure Receptors Oxytocin Hypotension business 030217 neurology & neurosurgery circulatory and respiratory physiology medicine.drug |
Zdroj: | American Journal of Physiology-Regulatory, Integrative and Comparative Physiology. 318:R160-R172 |
ISSN: | 1522-1490 0363-6119 |
DOI: | 10.1152/ajpregu.00050.2019 |
Popis: | The present study was designed to determine the role of centrally acting oxytocin (OT) in the regulation of blood pressure during chronic mild stress (CMS) in spontaneously hypertensive (SHR; n = 36) and normotensive Wistar-Kyoto (WKY; n = 38) rats. The rats were implanted with osmotic minipumps for intracerebroventricular infusions of 0.9% NaCl, OT, and oxytocin receptor antagonist (OTANT) and divided into two groups: SHR and WKY 1) exposed to 4-wk CMS and 2) not exposed to stress (controls). After 4 wk, hemodynamic parameters were recorded at rest and after an application of acute stressor [air-jet stress (AJS)]. Resting mean arterial blood pressure (MAP) was significantly lower in CMS-exposed SHR and WKY infused with OT than in the corresponding groups receiving saline. Exposure to CMS exaggerated the AJS-dependent pressor response in WKY receiving saline but not in the corresponding group of SHR. OT infusion reduced the AJS-dependent pressor response in both CMS-exposed and not exposed SHR and in CMS-exposed WKY. Intracerebroventricular infusion of OTANT potentiated the AJS-dependent pressor response in both stressed and not stressed WKY rats but not in SHR. The results show that centrally delivered OT decreases resting MAP during CMS in both SHR and WKY rats and that in SHR it reduces pressor responses to AJS under control and CMS conditions, whereas in WKY this effect is significant only after CMS exposure. The study indicates that endogenous centrally acting OT may play an essential role in buffering pressor responses to AJS in CMS-exposed and not exposed WKY rats and that this function is significantly impaired in SHR. |
Databáze: | OpenAIRE |
Externí odkaz: |