Involvement of the Cervical Sympathetic Nervous System in the Changes of Calcium Homeostasis during Turpentine Oil-Induced Stress in Rats

Abstract

Hypocalcemia is a common finding during stress. The objective of this study was to examine: (a) the changes in circulating calcium, parathyroid hormone (PTH) and calcitonin (CT) concentration in rats stressed by being given a subcutaneous injection of turpentine oil, and (b) the involvement of the sympathetic cervical pathway in stress-induced changes of calcium homeostasis. Four hours after receiving turpentine oil or vehicle, rats were subjected either to hypocalcemia, by being given EDTA intraperitoneally, or to hypercalcemia, by being injected CaCI₂ intraperitoneally. Significant changes in serum calcium (10% decrease), serum PTH (28% increase) and CT levels (40% decrease) were observed in stressed rats. EDTA administration brought about a significantly greater hypocalcemia, and a higher PTH secretory response in turpentine oil-stressed rats. During stress, the increase of serum calcium after CaCI₂ was significantly smaller, and the rise of CT was greater than in controls. In the case of CT the changes were still observed in rats subjected to superior cervical ganglionectomy (SCGx) 14 days earlier. In the case of PTH, the increase found in stressed rats, but not the augmented response after EDTA, was blunted by SCGx. The potentiation of hypocalcemia brought about by turpentine oil was no longer observed in SCGx rats. In vehicle-treated controls, SCGx delayed PTH response to hypocalcemia, but did not affect the increased response of CT to CaCI₂ challenge. The results indicate that a number of changes in calcium homeostasis arise during turpentine oil stress in rats. SCGx was effective to modify the set point for PTH release, but played a minor role in affecting the augmentation of CT release during stress.

Safety and Efficacy of Propofol With EDTA When Used for Sedation of Surgical Intensive Care Unit Patients

“…Little difference was observed in the change from baseline in mean ionised calcium, total calcium, or total magnesium concentrations between groups, and none of these differences were considered to be of clinical significance. Because surgical or trauma patients in an ICU are susceptible to increased stress and because hypocalcaemia commonly occurs during stress [18], patients were evaluated for evidence of hypocalcaemia at baseline and during sedation. Intermittent, mild hypocalca-S 457 emia was reported in a similar number of patients in the 2 groups at baseline and during sedation.…”

“…The mean rates of infusion for the propofol and propofol EDTA groups were 32. 18 The overall dose of propofol or propofol EDTA, the duration of sedation, and the time to extubation were greater in patients with APACHE II scores ³ 19; similarly, the number of patients with adverse events, number of treatment-related adverse events, and number of serious adverse events were all greater in patients with APACHE II scores ³ 19. There were no deaths among the 33 patients in the propofol EDTA group for whom APACHE II data were available (see section on Adverse Events for further analysis of mortality).…”

Correlation between serum and urinary calcium levels and psychopathology in patients with affective disorders

“…In a study in rats, we reported a fall of total serum calcium concentration, an increase of serum PTH, and a decrease of calcitonin levels during a mild stress caused by the subcutaneous injection of turpentine oil (Stern et al, 1993). Stress sequela were partially suppressed by excising the superior cervical ganglia, the major source of sympathetic innervation of parathyroid and thyroid glands, underlining the participation of cervical autonomic nerves in calcium homeostasis.…”

Neuroimmunoendocrinology of the cervical autonomic nervous system

“…A reasonable explanation for these results is that the supraliminal release of NE, a catecholamine displaying a greater activity on a-than on P-adrenoceptors, from the degenerating terminals produces activation of both types of adrenoceptor on C-cells, the cceffects being predominant. In a series of studies designed to examine the C-cell response to stress, as well as the participation of SCO neurons in rats injected with turpentine oil, we found that removal of the SCG had a relatively minor effect on stress-induced depression of calcitonin release (68)(69)(70).…”

“…The general pattern of PTH response differed significantly showing a slower response in SCGx rats the results indicating a modified sensitivity of parathyroid cells after chronic regional sympathetic denervation. To assess whether the cervical sympathetic nervous system was involved in conveying information to parathyroid cells on stress, a bilateral SCGx was performed in rats 14 days before to turpentine oil administration (68). SCGx blocked partially the PTH increase observed after turpentine oil injection.…”