E-rosette formation by human lymphocytes incubated with sheep red blood cells (sRBC) is inhibited by morphine. We studied the ability of the opiate antagonists naloxone and Tyr-MIF-1 (Tyr-Pro-Leu-Gly-NH2) to block this action. Active E-rosette formation by lymphocytes incubated with morphine was reduced from the control of 35.7±1.7% to 23.7±1.5% (p<0.001). Similarly, total E-rosette formation was reduced by morphine from the control of 65.8±1.3% to 53.2±2.9% (p<0.001). These effects were blocked by co-incubation of the lymphocytes with either Tyr-MIF-1 or naloxone (p<0.05). Tyr-MIF-1 was active (p<0.05) at concentrations as dilute as 10-13M. These results indicate that the neuropeptide Tyr-MIF-1 exerts an antiopiate effect at the human T-lymphocyte.

Naloxone (NAL) is administered parenterally or intranasally for treating opioid overdose. The short duration of action of NAL calls for frequent re-dosing which may be eliminated by the development of a transdermal system. This study aimed to assess the effect of microneedles on improving the skin permeation of NAL hydrochloride. In vitro permeation of NAL across intact and microneedle-treated (Dr. Pen™ Ultima A6) porcine skin was evaluated. The effect of microneedle length and application duration, and donor concentration on NAL permeation were investigated. In-vitro in-vivo correlation of the permeation results was done to predict the plasma concentration kinetics of NAL in patients. In vitro passive permeation of NAL after 6 h was observed to be 8.25±1.06 µg/cm2. A 56- and 37-fold enhancement was observed with 500 and 250 µm needles applied for 1 min, respectively. Application of 500 µm MNs for 2 min significantly reduced the lag time to ~ 8 min and increasing the donor concentration for the same treatment group doubled the permeation (p < 0.05). Modeling simulations demonstrated the attainment of pharmacokinetic profile of NAL comparable to those obtained with the FDA-approved intramuscular and intranasal devices. Microneedle-mediated transdermal delivery holds potential for rapid and sustained NAL delivery for opioid overdose treatment.

Indiana University-Purdue University Indianapolis (IUPUI) / Deaths due to prescription painkillers and heroin have quickly become national, state, and local public health concerns. Studies using data from Medical Examiners or Coroner Offices throughout the United States have been conducted and are contributing to the understanding of this epidemic. However, the analysis of these fatalities are specific to the communities where the study was conducted and cannot be assumed that the decedents in one community are similar to decedents in another community. Many local governments and agencies throughout the U.S. are aware that this problem exists in their communities, but are not prepared to adequately respond to and intervene in these fatalities as an analysis of those who have died has rarely been conducted. This dissertation is a replication study of longitudinal epidemiological analyses of opiate related fatalities that was implemented in a location where an analysis of opiate-related fatalities had not been conducted, Marion County, Indiana. The purpose of the dissertation was twofold: (1) to describe the demographic characteristics of the decedents using publicly available data from the Marion County Coroner’s Office to be used in informing future preventative efforts to decrease opiate-related fatalities in Marion County and (2) to inform other communities on how to conduct a similar analysis in their own community. This dissertation describes the methods of the replication study, provides descriptive results of the people who died from opiate-related overdoses, and: (a) Report the types of opiates identified in blood toxicology reports and (b) Present the histories of opiate-related decedents as reported in the Deputy Coroner Field Officer’s Reports (DCFOR). Additionally, analysis was conducted to determine if decedent characteristics deferred depending on the type of opiate fatality based on the toxicology in 1) heroin alone, 2) painkillers alone, and 3) heroin and painkillers combined.

No description available.

No description available.

Because endorphin receptor activation alters the function of the central noradrenergic system, opiates may change the regenerative sprouting of neurons in response to adrenergic neurotoxins. To test this hypothesis, newborn rats were treated with several opioids and 6-hydroxydopa (6-OHDOPA) and the development of the noradrenergic system was evaluated. In combination with 6-OHDOPA morphine and naloxone potentiated the development of norepinephrine (NE) levels in the pons-medulla and cerebellum by four weeks of age. β-Endorphin, Leu- and Met-enkephalin and d-Ala2-enkephalinamide produced a similar effect in the pons-medulla. The effect of morphine was partially attenuated by naloxone. Increased cerebellar noradrenergic histofluorescent staining was observed with the morphine + 6-OHDOPA and naloxone + 6-OHDOPA treatments. Both naloxone and morphine decreased NE levels in the pons-medulla of adult rats treated with 6-OHDOPA. These results suggest that opiates and endorphins may enhance sprouting of noradrenergic neurons following neonatal treatment with 6-OHDOPA, by increasing the toxicity of this neurotoxin.

Four experiments were conducted to investigate the effect of naloxone, an opioid receptor antagonist, on pituitary LH secretion in Holstein cows during two periods after parturition and two phases of the estrous cycle. In experiment 1, 24 cows (12 primiparous; 12 multiparous) received either saline (n = 12) or 1 mg/kg naloxone (n = 12) i. v. at 14 1 days postpartum. Blood samples were collected at 15-minute intervals for 2 hours before and 2.5 hours after naloxone or saline. Serum LH concentrations increased (P < .05) in response to naloxone injection in both primi- and multiparous cows. Saline injection did not affect LH concentrations. In experiment 2, 27 cows (13 primiparous; 14 multiparous) received either saline (n=14) or 1 mg/kg naloxone (n=13) i. v. at 28 ± 1 days postpartum. Blood samples were collected as in the previous experiment. Naloxone did not affect serum LH concentrations in either primi- or multi-parous cows at 28 days postpartum. In experiment 3, estrous cycles were synchronized via prostaglandin administration (25 mg) in 22 cows (10 primiparous; 12 multiparous). Cows received either saline (n=11) or 1 mg/kg naloxone (n=11) Lv. during the luteal phase of the estrous cycle. Blood samples were collected as in the previous experiments. Luteinizing hormone concentrations were not affected by naloxone in either primi- or multi-parous cows during the luteal phase of the estrous cycle. In experiment 4, the same cows used in experiment 3 received a second dose of prostaglandin (25 mg). Thirty-six hours later, during the follicular phase of the estrous cycle, the cows received either saline (n =9) or 1 mg/kg naloxone (n = 11) i. v. Naloxone increased (P < .05) serum LH concentrations in both primi- and multi-parous cows in the follicular phase. These results suggest that LH release in the early postpartum dairy cow is regulated, at least in part, by endogenous opioid pep tides , and the ability of naloxone to affect LH secretion may change as days postpartum increases, perhaps due to changes in degree of inhibition by endogenous opioid peptides, and (or) changes in serum progesterone concentration due to onset of ovarian activity during postpartum period. It appears that the modulation of LH secretion may be mediated via opioids during the follicular phase of the estrous cycle. However, an opioid-mediated mechanism for modulation of LH secretion was absent or overridden by progesterone feedback during the luteal phase of the estrous cycle. / Master of Science

No description available.

Opioid/adrenergic interactions were studied to evaluate two hypotheses: (1) naloxone potentiates the effect of epinephrine on cardiac contractility by increasing circulating epinephrine concentrations; and (2) endogenous and exogenous opioids alter left cardiac nerve stimulationinduced norepinephrine release and cardiac function. A canine isolated heart-lung preparation was used for the first study. Plasma epinephrine was determined and myocardial epinephrine uptake was calculated during intravenous epinephrine infusion. Naloxone (4 mg) was given and the epinephrine infusion was repeated. Naloxone increased cardiac contractility, coronary blood flow, and the coronary sinus epinephrine concentration. When coronary blood flow was subsequently held constant (100% above resting), naloxone increased only contractility. This result indicated that the previously observed increase in coronary sinus epinephrine was flow dependent. Corticosterone (an uptake II blocker) was employed as a positive control. Corticosterone increased the contractile response to epinephrine, but unlike naloxone, corticosterone was accompanied by a clear decrease in myocardial epinephrine uptake. The stereospecificity of the response to naloxone was investigated and (+) naloxone equaled or exceeded (-) naloxone in potentiating the inotropic effect of epinephrine. In the second study, the left cardiac nerve was isolated and electrically stimulated in intact dogs. Norepinephrine overflow gradually declined during successive control stimulations. Pretreatment with naloxone (100 Mg/kg) prevented or delayed the decline. An intracoronary dynorphin 1-9 infusion (2 nmol/min/kg for 20 minutes) reduced both norepinephrine overflow and cardiac performance, and both effects were prevented by pretreatment with naloxone (100 /xg/kg) . To summarize, naloxone potentiated the inotropic effect of infused epinephrine without altering circulating epinephrine concentrations or myocardial epinephrine uptake. This effect of naloxone was not stereospecific and probably not mediated through a traditional opiate receptor. Endogenous and exogenous opioids inhibited the left cardiac nerve stimulation-induced norepinephrine overflow, suggesting that opiate receptors may regulate cardiac excitability by modulating norepinephrine release.

Aferentes nociceptivos primários se projetam da periferia para o corno posterior da medula espinhal onde ativam grande número de neurônios de segunda ordem e de projeção. Há evidências de que a passagem de informações nociceptivas pelo CPME seguindo para níveis rostrais do sistema nervoso central, sofre profundas influências excitatórias e inibitórias. A presente pesquisa teve como objetivo comparar os efeitos dos antagonistas de opióides (naloxona), de serotonina (metissergida) e de noradrenalina (fentolamina), administrados por via subaracnóidea, sobre as fases I, intermediária e II do teste da formalina modificado, em ratos. Para tanto, foram utilizados 35 ratos wistar machos, pesando entre 220 e 300 gramas, distribuídos aleatoriamente em cinco grupos (n = 7) para receber solução salina (GC), fentolamina (GF), naloxona (GN), metissergida (GM) ou fentolamina associada a metissergida (GFM). A indução da dor foi realizada com administração de solução de formalina na região dorsal da pata posterior direita. Todas as elevações da pata, não relacionadas à marcha foram consideradas e a contagem foi realizada continuamente durante o período de 60 minutos. O teste foi dividido em três fases; fase I, intermediária e fase II, sendo que a fase I compreendeu o número de elevações durante os primeiros 5 minutos, a fase intermediária do sexto ao vigésimo minuto e a fase II, do vigésimo primeiro ao sexagésimo minuto. A análise estatística dos resultados obtidos foi realizada utilizando o programa SPSS (Statistical Package for Social Sciences), adotando o nível de significância de 5%. Para as variáveis: peso, idade e fase I do teste, os grupos foram estatisticamente semelhantes. Nos cinco grupos estudados, a fase intermediária diferenciou-se das outras duas, enquanto que as fases I e II foram estatisticamente semelhantes. Para a variável fase intermediária foi encontrada uma diferença estatisticamente significante entre os grupos GF, GM e GFM quando comparados com os grupos GC e GN, e para a variável fase II foi encontrada diferença significante entre o grupo GN em comparação a todos os outros grupos. No presente estudo, a metissergida e a fentolamina se mostraram eficazes em inibir o efeito modulador espinhal da dor, sugerindo efeito noradrenérgico e serotoninérgico inibitório da transmissão nociceptiva espinhal, sem haver efeito somatório ou potencializador quando utilizados em associação. Entretanto, estes efeitos não foram observados com naloxona, e assim um efeito opióide modulador espinhal, na interfase do teste não ficou estabelecido. Durante a fase II, a naloxona causou redução da resposta nociceptiva à formalina, corroborando a hipótese de que exerça atividade sobre os receptores -opiáceos / Primary nociceptive afferents are projected from the periphery to the dorsal horn of the spinal cord, where they activate a large number of second-order and spinal projection neurons. There are evidences that the passage of nociceptive information through the posterior horn of the spinal cord towards rostral levels of the central nervous system (CNS) are under profound excitatory and inhibitory influences. This research had as objective to compare the effects of the naloxone, methysergide and phentolamine, administered by intrathecal route, under phases I, II and intermediary of the modified formalin test in rats. Therefore, 35 male Wistar rats between 220 and 300 grams, randomly distributed in five groups (n = 7) to receive saline solution (GS), phentolamine (GF), naloxone (GN), methysergide (GM) or phentolamine associated to methysergide (GFM) were used. The induction of pain was performed with administration of formalin solution in the dorsal region of the posterior right paw. All paw lifting, not related to the march, were taken into account and the count was continuously performed during the 60 minute period. The test was divided into three phases: phase I, intermediary and phase II, whereas phase I comprised the number of elevations during the first five minutes, the intermediary phase from the sixth to the twentieth minute, and phase II, the number of elevations from the twentieth first minute up to the sixtieth minute to the sixtieth minute. The statistical analysis of the results obtained was performed using the program SPSS (Statistical Package for Social Sciences), adopting a 5% significance level. For the variables: Weight, age and phase I of the test, the groups were statistically similar. In the five studied groups, the intermediary phase was different from the other two, while phases I and II were statistically similar. For the intermediary phase variable it was found a statistically significant difference among groups GF, GM, GFM when compared with groups GS and GN, and for the phase II variable it was found significant difference between group GN when compared with groups GC, GF, GM and GFM. In this study, methysergide, a non-selective antagonist of receptors 5-HT and phentolamine, a non-selective adrenoceptor antagonist, were effective in inhibiting the spinal pain modulating effect, suggesting inhibitory noradrenergic and serotonergic effect of spinal nociceptive transmission. However, such effects were not noticed with naloxone, and thus, a modulating spinal opioid effect was not established in the test interphase. During phase II of the formalin test, naloxone causes the decrease of nociceptive response to formalin, suggesting that the k-opiate receptors are involved in naloxone-induced analgesia.