Effect of chronic morphine treatment and naloxone precipitated morphine withdrawal on neuropeptide expression in the hypothalamus.

<p>Mean (±SEM) values of relative expression values of selected hypothalamic neuropeptide mRNAs in placebo or morphine treated rats two hours after saline or naloxone injection. Neuropeptide mRNA levels were normalised to GAPDH levels and expressed as fold change compared to the levels of placebo implanted saline groups set to 1. n = 6/group, *p<0.0.1 compared to saline injected respective controls.</p

Time course of relative expression levels of stress- and metabolic-related neuropeptide genes in the hypothalamus during naloxone precipitated morphine withdrawal.

<p>Mean (±SEM) fold change values of CRH, UCN2, POMC, NPY and AVP mRNAs in the hypothalamus of morphine-implanted naloxone injected (solid bars) compared to placebo-implanted saline injected animals (open bars). All values were normalized to GAPDH levels and shown as fold changes compared to levels of morphine and placebo implanted animals sacrificed at time 0, respectively. n = 5/time point, *p<0.05; **p<0.01; ***p<0.001, compared to placebo implanted, saline injected group (at the same time point).</p

Plasma hormone levels and blood glucose concentration 7 days after morphine or placebo implantation and 2 hours after saline or naloxone injection.

+<p>p<0,05 placebo+saline vs. placebo+naloxone; *p<0,05 morphine+saline vs. morphine+naloxone group; n = 6/group.</p

Mean±SEM plasma hormone concentrations in placebo- or morphine implanted and pair-fed rats 2 or 7 days after pellet implantation.

*<p><i>p</i><0,05 morphine vs. pair fed;⁺<i>p</i><0,05 placebo vs. morphine; n = 7/group.</p

Effects of chronic morphine treatment and pair feeding on metabolic parameters of male rats.

<p>Daily changes of food intake in placebo and morphine implanted animals. Pair fed rats were placebo implanted and received the same amount of food that was consumed by the morphine implanted pairs. n = 12, ⁺<i>p</i><0.05, ⁺⁺<i>p</i><0.01 morphine vs. placebo-implanted group (Student’s t-test) A. Mean (±SEM) values of daily changes in body weight of morphine implanted and placebo implanted and pair fed rats. Note that pair feeding of placebo implanted rats resulted in significantly more body weight loss compared to morphine implanted animals, n = 12, *<i>p</i><0.05 placebo implanted vs. pair fed group (Student’s t-test).</p

Time course of weight loss during morphine withdrawal.

<p>Mean (±SEM) values of body weight change in morphine implanted, naloxone injected- (solid dots) and placebo implanted, saline injected rats (open dots) at different time points after injection. n = 16/group, p<0.01 compared to time 0.</p

Mean±SEM relative expression levels of selected hypothalamic neuropeptides in placebo or morphine-treated and pair fed animals 2 or 7 days after pellet implantation.

*<p><i>p</i><0,01 placebo vs. pair fed; ^#<i>p</i><0,01 morphine vs. pair fed; ⁺<i>p</i><0,001 placebo vs. morphine; n = 7/group.</p

Schematic overview of the pair feeding and time course experiments.

<p>Baseline food intake (FI) and body weight (BW) data were obtained on days −2 and −1. On day 0 rats were subcutaneously implanted with placebo or morphine pellets. Based on the food consumption data of morphine implanted rats, a group of placebo implanted, pair fed rats was added on day 1. These rats received the same amount of food daily that was consumed by their morphine-implanted pairs on the previous day. Some morphine and placebo treated rats were decapitated on day 2 along their placebo-implanted, pair fed partners on day 3. On day 7, placebo and morphine-implanted groups were further divided into two groups half of the rats from each group received subcutaneous injection of saline or naloxone and sacrificed at different time points thereafter. Animals from pair fed group were decapitated on day 8 (7^th day after pellet implantation).</p

List of primer pairs used in real-time quantitative PCR reactions.

<p>List of primer pairs used in real-time quantitative PCR reactions.</p