Effects of ketoprofen for prevention of postoperative cognitive dysfunction in aged rats.

Postoperative cognitive dysfunction is a common geriatric complication that may be associated with increased mortality. Here, we investigated the effects of postoperative analgesia with ketoprofen on cognitive functions in aged animals and compared its effectiveness to morphine. Rats were randomly allocated to one of four groups: isoflurane anesthesia without surgery (group C), isoflurane anesthesia with laparotomy (group IL), and isoflurane anesthesia with laparotomy plus postoperative analgesia with ketoprofen or morphine.

Preventive effects of multisensory rehabilitation on development of cognitive dysfunction following systemic inflammation in aged rats.

Systemic inflammation can trigger transient or longer-lasting cognitive impairments, particularly in elderly patients. However, its pathogenesis has not been sufficiently clarified. In this study, we explored the potential effects of multisensory rehabilitation on cognitive dysfunction following systemic inflammation using an animal model.

Postoperative pain impairs subsequent performance on a spatial memory task via effects on N-methyl-D-aspartate receptor in aged rats.

Aims: Pain may be associated with postoperative cognitive dysfunction (POCD); however, this relationship remains under investigated. Therefore, we examined the impact of postoperative pain on cognitive functions in aged animals.

Main Methods: Rats were allocated to the following groups: control (C), 1.

Activation of ATP-sensitive potassium channels by nicorandil is preserved in aged vascular smooth muscle cells in rats.

Nicorandil, an ATP-sensitive potassium (KATP) channel opener having the properties of a nitrate, causes vasodilation, particularly of coronary arteries, and has been reported to reduce the frequency of perioperative cardiac events. We previously demonstrated that isoflurane could activate vascular KATP channels through an intracellular signaling pathway, but that this isoflurane-induced channel opening is suppressed by aging. Here, we investigated whether advanced age modifies nicorandil-induced activation of vascular KATP channels.

Biophysical and pharmacological properties of glucagon-like peptide-1 in rats under isoflurane anesthesia.

Background: Glucagon-like peptide-1 (GLP-1) increases insulin secretion and has an important role in maintaining glucose homeostasis. In this study, we evaluated the biophysical and pharmacological properties of GLP-1 by performing in vivo and in vitro experiments to determine the applicability of GLP-1 in glycemic control in rats under isoflurane anesthesia.

Methods: Levels of portal GLP-1, insulin, and glucose and dipeptidyl peptidase-4 activity were measured in the basal fasting state and after gastric glucose load before, during, and after exposure to 30% O(2) in air (control) or 1.

Dexmedetomidine directly inhibits vascular ATP-sensitive potassium channels.

Aims: Dexmedetomidine is reported to have an effect on peripheral vasoconstriction; however, the exact mechanisms underlying this process are unclear. In this study, we hypothesized that dexmedetomidine-induced inhibition of vascular ATP-sensitive K(+) (K(ATP)) channels may be associated with this vasoconstriction. To test this hypothesis, we investigated the effects of dexmedetomidine on vascular K(ATP)-channel activity at the single-channel level.

The involvement of the neurosteroid allopregnanolone in the antihyperalgesic effect of paroxetine in a rat model of neuropathic pain.

Paroxetine increases the levels of neurosteroids, such as allopregnanolone (AP), that influence the excitability of the central nervous system by positive allosteric modulation of γ-aminobutyric acid type A receptors. Here, we investigated the role of AP synthesis on the paroxetine-induced antihyperalgesic effect in a rat model of neuropathic pain induced by lumbar spinal nerve ligation (SNL). Subcutaneous administration of paroxetine in SNL rats, dose-dependently decreased the probability of hyperalgesic response and increased AP levels in the spine but not in either brain or serum.

Role of the neurosteroid allopregnanolone in the hyperalgesic behavior induced by painful nerve injury in rats.

The neurosteroid allopregnanolone (AP) influences the excitability of the central nervous system by acting as a positive allosteric modulator of γ-aminobutyric acid type A (GABA(A)) receptors. Here, we investigated the role of AP and its therapeutic potential in rats that showed hyperalgesic behavior after undergoing spinal nerve ligation (SNL). AP levels measured in the spinal cord and brain of rats that underwent SNL were greater than the corresponding levels in control animals.