Acute hypercalcemia in the conscious, unanesthetized rat, achieved by a 30-minute infusion of CaCl2 (serum calcium level, 12.8 +/- 0.6 mg/dl) resulted in significant elevation of mean arterial pressure (from 112 +/- 2 mm Hg to 129 +/- 3 mm Hg, p less than 0.001). This pressor response was associated with a significant increase in systemic vascular resistance, from 0.45 +/- 0.02 mm Hg/(ml/min)/kg body weight to 0.50 +/- 0.02 mm Hg/(ml/min)/kg body weight (p less than 0.05), but it caused no alteration in cardiac index. The pressor response to acute hypercalcemia does not appear to be mediated by vasopressor hormones or attenuated by vasodepressor hormones since inhibition of the renin-angiotensin system (nephrectomy), catecholamines (central and peripheral 6-hydroxydopamine), vasopressin (vascular antagonist), prostaglandins (indomethacin), and parathyroid hormone (parathyroidectomy) did not significantly alter the pressor response to infusion of CaCl2 in spite of similar serum calcium levels in all groups of animals. Rather, the pressor response to acute hypercalcemia seems to be mediated by a direct action of calcium ion on smooth muscle and perhaps myocardial cell contractility, since pretreatment with the calcium channel blockers verapamil or nifedipine blocked the pressor response to acute hypercalcemia.
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http://dx.doi.org/10.1161/01.hyp.7.6.923 | DOI Listing |
Eur J Appl Physiol
January 2025
Department of Physical Therapy & Rehabilitation Science, Carver College of Medicine, the University of Iowa, Iowa City, IA, 52242, USA.
Nociceptors contribute to the cardiovascular responses during a cold pressor test (CPT). While these responses are lower in females, data suggest that they perceive the CPT as more painful. Thus, we examined sex differences in associations between pain and cardiovascular responses to a CPT (Aim 1) as well as differences between females using (OC), and not using (NC), an oral contraceptive (Aim 2).
View Article and Find Full Text PDFClin Auton Res
January 2025
Department of Health and Kinesiology, Purdue University, West Lafayette, Indiana, USA.
Purpose: Resting beat-to-beat blood pressure variability is a strong predictor of cardiovascular events and mortality. However, its underlying mechanisms remain incompletely understood. Given that the sympathetic nervous system plays a pivotal role in cardiovascular regulation, we hypothesized that alpha-1 adrenergic receptors (the main sympathetic receptor controlling peripheral vasoconstriction) may contribute to resting beat-to-beat blood pressure variability.
View Article and Find Full Text PDFAJNR Am J Neuroradiol
January 2025
From the Department of Radiology, Medical Physics (MML, TJC), Department of Interventional Radiology (NS, GAC), Department of Surgery and Large Animal Studies (MAN), and the Department of Statistics (MG), University of Chicago, Chicago, IL, USA; Department of Anesthesiology (SPR), University of Illinois, Chicago, IL, USA; Department of Radiology (MSS), University of Massachusetts Chan Medical School, Worcester, MA, USA; Department of Radiology, Biomedical Engineering and Imaging Institute (Current affiliation MML), Icahn School of Medicine at Mount Sinai, New York, NY, USA; Mount Carmel Health Systems (Current affiliation GAC), Columbus, OH, USA.
Background And Purpose: In acute ischemic stroke, the amount of "local" CBF distal to the occlusion, i.e. all blood flow within a region whether supplied antegrade or delayed and dispersed through the collateral network, may contain valuable information regarding infarct growth rate and treatment response.
View Article and Find Full Text PDFInt J Behav Med
January 2025
Department of Clinical Psychological Science, Maastricht University, Maastricht, The Netherlands.
Background: Previous studies demonstrated that task-specific stress appraisals as well as the more general belief that stress is (mal)adaptive (i.e., stress mindset) can affect the stress response.
View Article and Find Full Text PDFAnxiety Stress Coping
January 2025
Neuroendocrine Unit, Department of Medicine, Massachusetts General Hospital and Harvard Medical School, Boston, MA, USA.
Background And Objectives: Laboratory-based stress inductions are commonly used to elicit acute stress but vary widely in their procedures and effectiveness. We compared the effects of stress induction techniques on measures of two major biological stress systems: the early sympathetic-adrenal-medullary (SAM) and the delayed hypothalamic-pituitary-adrenal (HPA) axis response.
Design: A review and meta-analysis to examine the relationship between stress induction techniques on cardiorespiratory and salivary measures of SAM and HPA system activity.
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