Plasma histamine and hemodynamic responses following administration of nalbuphine and morphine

Effects of morphine on histamine release from two cell lines of canine mast cell tumor and on plasma histamine concentrations in dogs with cutaneous mast cell tumor

OBJECTIVE

To determine the effects of morphine on histamine release from 2 canine mast cell tumor (MCT) cell lines and on plasma histamine concentrations in dogs with cutaneous MCTs.

ANIMALS

10 dogs with cutaneous MCT and 10 dogs with soft tissue sarcoma (STS).

PROCEDURES

The study consisted of 2 phases. First, 2 canine MCT cell lines were exposed to 3 pharmacologically relevant morphine concentrations, and histamine concentrations were determined by an ELISA. Second, dogs with MCT or STS received 0.5 mg of morphine/kg, IM, before surgery for tumor excision. Clinical signs, respiratory rate, heart rate, arterial blood pressure, rectal temperature, and plasma histamine concentrations were recorded before and 5, 15, 30, and 60 minutes after morphine administration but prior to surgery. Data were compared by use of a 2-way ANOVA with the Sidak multiple comparisons test.

RESULTS

In the first phase, canine MCT cell lines did not release histamine when exposed to pharmacologically relevant morphine concentrations. In the second phase, no differences were noted for heart rate, arterial blood pressure, and rectal temperature between MCT and STS groups. Plasma histamine concentrations did not significantly differ over time within groups and between groups.

CONCLUSIONS AND CLINICAL RELEVANCE

No significant changes in histamine concentrations were noted for both in vitro and in vivo study phases, and no hemodynamic changes were noted for the in vivo study phase. These preliminary results suggested that morphine may be used safely in some dogs with MCT.

Pharmacokinetics and physiological effects of two intravenous infusion rates of morphine in conscious dogs

This study examined the pharmacokinetics and physiologic effects of two infusions rates of morphine in conscious dogs. Five adult dogs were randomly studied at weekly intervals. An initial dose of either 0.3 or 0.6 mg/kg were each followed by infusions of 0.17 and 0.34 mg/kg/h. Plasma morphine concentrations, physiological parameters, sedation and mechanical antinociception were evaluated during each infusion. Morphine was assayed by high pressure liquid chromatography (HPLC) with electrochemical coulometric detection and pharmacokinetic parameters were calculated. Data were fitted to a bi-compartment model with a rapid distribution (<1 min for both doses) and slower termination rate. For the high and low doses, respectively, mean+/-SD terminal half-life was 38+/-5 and 27+/-14 min, apparent volumes of distribution at steady-state were 1.9+/-0.5 and 1.3+/-0.8 L/kg, with clearances of 50+/-15 and 67+/-20 mL/kg/min. Steady-state plasma concentrations ranged from 93 to 180 ng/mL and 45 to 80 ng/mL in the high and low doses, respectively. Respiratory rate increased significantly, pulse oximetry remained>95% and body temperature decreased significantly during both infusions. No vomition or neuroexcitation occurred. Sedation and mechanical antinociception were both mild during the lower infusion rate, and mild to moderate during the higher infusion rate. In conclusion, morphine pharmacokinetics was not altered by increasing infusion rates, producing stable, long-lasting plasma concentrations.

Histamine increases sickle erythrocyte adherence to endothelium

Complications of sickle cell anaemia include vascular occlusion triggered by the adherence of sickle erythrocytes to endothelium in the postcapillary venules. Adherence can be promoted by inflammatory mediators that induce endothelial cell adhesion molecule expression and arrest flowing erythrocytes. The present study characterised the effect of histamine stimulation on the kinetics of sickle cell adherence to large vessel and microvascular endothelium under physiological flow. Increased sickle cell adherence was observed within minutes of endothelial activation by histamine and reached a maximum value within 30 min. At steady state, sickle cell adherence to histamine-stimulated endothelium was 47 +/- 4 adherent cells/mm(2), 2.6-fold higher than sickle cell adherence to unstimulated endothelial cells. Histamine-induced sickle cell adherence occurred rapidly and transiently. Studies using histamine receptor agonists and antagonists suggest that histamine-induced sickle cell adhesion depends on simultaneous stimulation of the H(2) and H(4) histamine receptors and endothelial P-selectin expression. These data show that histamine release may promote sickle cell adherence and vaso-occlusion. In vivo histamine release should be studied to determine its role in sickle complications and whether blocking of specific histamine receptors may prevent clinical complications or adverse effects from histamine release stimulated by opiate analgesic treatment.

Evaluation of histamine release during constant rate infusion of morphine in dogs

OBJECTIVE

To evaluate histamine release and selected physiologic variables during constant rate infusion (CRI) of morphine in dogs.

ANIMALS

Five healthy, conscious, intact female dogs.

MATERIAL AND METHODS

Using a Latin square, repeated-measures design, dogs were randomly assigned to three treatment groups to receive a 4-hour CRI of saline (SAL), or a loading dose of morphine at 0.3 mg kg(-1) (LM), or 0.6 mg kg(-1) (HM), followed by an infusion of 0.17 mg kg(-1) hour(-1) (LM) and 0.34 mg kg(-1) hour(-1) (HM) respectively. Dogs received each of the three treatments at intervals of at least 7 days. Plasma histamine concentration, skin flushing, edema and wheals, heart rate and rhythm and non-invasive arterial blood pressure were measured before the loading dose and at 1, 2, 5, 15, 30, 60, 120, 180 and 240 minutes during the CRI, or at the time of occurrence.

RESULTS

The loading dose induced the highest histamine release in the HM group being statistically higher than the SAL group. The histamine release obtained in the LM group after the loading dose did not differ from SAL. During the infusion, plasma histamine levels were numerically higher in the LM group. Besides one dog that developed hypotension for 2 minutes after the loading dose in the HM group and one dog that showed occasional ventricular premature contractions during both morphine infusions, cardiovascular variables were similar among the three treatment groups.

CONCLUSIONS AND CLINICAL RELEVANCE

Both doses of morphine induced variable histamine release with minimal adverse cardiovascular effects in these conscious, healthy dogs. The plasma histamine levels obtained may be associated with significant hemodynamic changes in patients with limited cardiovascular reserve and sympathetic nervous tone.

Morphine modulation of the contact hypersensitivity response: characterization of immunological changes

Previous investigations in our laboratory showed that systemic morphine administration 1 h prior to elicitation of the in vivo contact hypersensitivity (CHS) response produced a robust increase in inflammation at the site of antigen reexposure. The present study extended those findings by characterizing the effect of morphine on immunological processes important in the development of the CHS response. To induce contact hypersensitivity, the antigen 2,4-dinitrofluorobenzene was applied to the pinnae of previously sensitized rats. Morphine administration produced an increase in inducible nitric oxide synthase mRNA and the proinflammatory cytokine interleukin-6, at the site of antigen reexposure. In contrast, morphine did not alter expression of the anti-inflammatory cytokine interleukin-10. Morphine also produced an increase in the proliferation of lymphocytes from the peripheral (i.e., cervical) lymph nodes when assessed 72 h following challenge. These studies show that the morphine-induced increase in the in vivo CHS response involves immunologically specific alterations.

Characterization of histamine release induced by fluoroquinolone antibacterial agents in-vivo and in-vitro

Characterization of histamine release induced by fluoroquinolone antibacterial agents, levofloxacin and ciprofloxacin, was investigated in-vivo and in-vitro. Intravenous injection of levofloxacin and ciprofloxacin at 1-10 mg kg(-1) produced dose-related elevations in plasma histamine level in anaesthetized dogs. In contrast, levofloxacin was devoid of plasma histamine increment in anaesthetized rats at 100 mg kg(-1), whereas ciprofloxacin at the same dose caused endogenous histamine release. Levofloxacin and ciprofloxacin induced non-cytotoxic secretion of histamine from all mast cells tested in a concentration-dependent manner, whereas rat skin and peritoneal mast cells were thirty- to one-hundred-times less sensitive to the effect of fluoroquinolones as compared with the canine skin mast cells. These results suggest that the functional heterogeneity of mast cells from different species in histamine releasing activity of fluoroquinolones may exist, and that mast cells from the dog appear to be particularly sensitive to the effect of the fluoroquinolones.

Increased intestinal marker absorption due to regional permeability changes and decreased intestinal transit during sepsis in the rat

BACKGROUND

The intestinal barrier properties are impaired during inflammation and sepsis, but the mechanisms behind this are unknown and were therefore investigated during experimental sepsis in rats.

METHODS

The different-sized intestinal absorption markers 51Cr-labeled ethylenediaminetetraacetic acid (EDTA) and ovalbumin were gavaged to rats made septic by intra-abdominal bacterial implantation and to sham-operated rats. Regional tissue permeability was measured in diffusion chambers, and intestinal transit was evaluated by intestinal accumulation of gavaged 51Cr-EDTA.

RESULTS

In comparison with the sham-operated rats, septic rats had higher 51Cr-EDTA levels in blood and urine and showed a prolonged intestinal transit. Septic rats also had a lower tissue permeability to both markers in the small intestines but higher permeability to ovalbumin in the colon. Rats receiving morphine to decrease intestinal motility showed similar changes, with a decreased intestinal transit and increased marker absorption.

CONCLUSIONS

The results suggest that the increased intestinal absorption during sepsis was due to regional permeability changes and prolonged intestinal transit.

Opiates, mast cells and histamine release

Opiates have long been known to cause the release of histamine from mast cells, resulting in several undesirable effects, such as hypotension, urticaria, pruritus, and tachycardia. The mechanism of this opiate response has remained unclear, although it is known to be non-immunological in nature. A survey of the histamine-releasing properties of a variety of opiates shows that the pharmacology of opiate-induced histamine release from mast cells is distinct from that of known opiate receptors. Although functional opiate receptors may exist on mast cells and may be capable of modulating IgE-mediated histamine release, there is no evidence that these receptors account for opiate-induced histamine release. Since other basic compounds have been suggested to release histamine from mast cells by directly activating G-proteins, it seems possible that morphine and endogenous opiates may also share this mechanism.

Opioid peptides modulate immune functions. A review

In the past few years it has become evident that neuropeptides may be direct mediators in the modulation of the immune response and the unspecific defense by the brain. Lymphocytes have been thought to have opioid receptors and to respond to opioids with an increase in blastogenesis, cytotoxicity and factor release. Lymphocytes are said to release various neuropeptides. Furthermore, there are some unexplained effects of morphine on the immune system and of the immune system on morphine withdrawal. The purpose of this paper is to review what has been previously published in this field. The well established modulation of phagocyte functions by opioids will only be scanned.