Vasopressin V1a receptors are present in the carotid body and contribute to the control of breathing in male Sprague-Dawley rats

Publication date: Available online 7 March 2018 Source:Peptides Author(s): Tymoteusz Żera, Jacek Przybylski, Tomasz Grygorowicz, Kaja Kasarełło, Martyna Podobińska, Dagmara Mirowska-Guzel, Agnieszka Cudnoch-Jędrzejewska Vasopressin (AVP) maintains body homeostasis by regulating water balance, cardiovascular system and stress response. AVP inhibits breathing through central vasopressin 1a receptors (V1aRs). Chemoreceptors within carotid bodies (CBs) detect chemical and hormonal signals in the bloodstream and provide sensory input to respiratory and cardiovascular centers of the brainstem. In the study we investigated if CBs contain V1aRs and how the receptors are involved in the regulation of ventilation by AVP. We first immunostained CBs for V1aRs and tyrosine hydroxylase, a marker of chemoreceptor type I (glomus) cells. In urethane-anesthetized adult Sprague-Dawley male rats, we then measured hemodynamic and respiratory responses to systemic (intravenous) or local (carotid artery) administration of AVP prior and after systemic blockade of V1aRs. Immunostaining of CBs showed colocalization of V1aRs and tyrosine hydroxylase within glomus cells. Systemic administration of AVP increased mean arterial blood pressure (MABP) and decreased respiratory rate (RR) and minute ventilation (MV). Local administration of AVP increased MV and RR without significant changes in MABP or heart rate. Pretreatment with V1aR antagonist abolished responses to local and intravenous AVP ...

Source: Peptides - March 8, 2018 Category: Biochemistry Source Type: research