Effects of the dopamine D3 receptor agonist 7-hydroxy-2-(di-N-propylamino) tetralin in hyperthyroidism-induced premature ejaculation rat model

Various factors are involved in the aetiology of premature ejaculation (PE). Hyperthyroidism is one of the causes of acquired PE, but the exact mechanism by which it causes the disorder is not yet understood. The aim of this study was to evaluate the role of the dopaminergic system in hyperthyroidism-induced PE by the intracerebroventricular microinjection of the preferentially active dopamine receptor agonist 7-hydroxy-2-(di-N-propylamino) tetralin (7-OH-DPAT) in a rat model of this disorder. Wistar rats were randomly divided into hyperthyroid and control groups, and ejaculation was induced by the ICV administration of 7-OH-DPAT. To evaluate the emission and expulsion phases of ejaculation, measurements of seminal vesicle pressure (SVP) and electromyographic recordings of the bulbospongiosus muscle were taken. The interval between the 7-OH-DPAT administration and the first ejaculation was significantly less in the hyperthyroid group (p < .01) than in the control group, and the maximum amplitude of the SVP values revealed a statistically significant difference between the groups (p < .01). The intervals between contractions of the seminal vesicle and bulbospongiosus muscles were also significantly less in the hyperthyroid group (p = .0187) than in the control group. No other results differed significantly between the groups. This study determined that hyperthyroidism altered only the emission phase of ejaculation.

Soluble guanylyl cyclase activators increase the expression of tolerance to morphine analgesic effect

OBJECTIVES

It is aimed to investigate the effects of guanylyl cyclase activation and inhibition on acute morphine antinociception and the development of tolerance to its effect.

BACKGROUND

Nitric oxide-soluble guanylyl cyclase signal transduction cascade suggested to play an important role in the development of tolerance to antinociceptive effects of morphine.

METHODS

Nociception was evaluated by tail flick and hot plate tests in male Wistar rats. The analgesic effects of intraperitoneal protoporphyrin IX (PPIX; an activator of soluble guanylyl cyclase), 3-morpholinosydnonimine hydrochloride (SIN-1; NO donor and activator of guanylyl cyclase), S-Nitroso-N-acetylpenicillamine (SNAP; an activator of guanylyl cyclase), 3,3-Bis (amino ethyl)-1-hydroxy-2-oxo-1-triazene (NOC-18; NO donor activating guanylyl cyclase) and 1H-[1,2,4]oxadiazolo[4,3-a]quinoxalin-1-one (ODQ; an inhibitor of guanylyl cyclase) alone or in combination with subcutaneous morphine injection were evaluated. Their effects on morphine tolerance development were evaluated by giving these agents 20 minutes prior to twice daily morphine injection during tolerance development for 5 days. On day 6, the expression of morphine tolerance was determined.

RESULTS

PPIX, SIN-1, SNAP and NOC-18 significantly increased expression of morphine tolerance while ODQ decreased.

CONCLUSION

These data suggested that sGC activators have a significant role in tolerance to the analgesic effect of morphine (Tab. 1, Fig. 4, Ref. 29).

Pharmaceutical risk management in Turkey: the first national overview

Risk management plans and actions aim to limit the known risks of drugs and provide valuable data to evaluate actual risks and pre-disposing factors for adverse drug reactions. In this study, it is aimed to evaluate and summarize the risk management actions in Turkey between 2005 and 2013 for the first time. The drugs monitored with a risk management plan and actions taken are evaluated by examining the records of the Turkish Pharmaceuticals and Medical Devices Agency retrospectively. Various risk management actions such as provision of information, summary of product characteristics and patient information leaflets, direct communication with healthcare professionals, patient and physician brochures, change of the legal status of the drug, education of doctors and pharmacists, control of number and validity of prescriptions, using informed consent forms, using "drug safety surveillance form" for the TNF blockers (firstly on the world), using web-based monitoring system, web-based prescription and web-based adverse reaction monitoring system were used for safe use of drugs during and after authorization in Turkey. Although, most of the actions are similar to those of international health authorities, the remaining are specific to the conditions of Turkey such as "drug safety surveillance form" for the TNF blockers.

The effects of L type calcium channels on the electroencephalogram recordings in WAG/RIJ rat model of absence epilepsy

BACKGROUND

Epilepsy is one of the most important central nervous system disorder and 1% of the total world population suffers from this disorder which require a chronic drug treatment. Most of the researchers suggested that excessive calcium entry into neurons is the main triggering event in the initiation of epileptic discharges but the role of L type calcium channels has not been clarified in absence epilepsy.

AIM

In this study, it is aimed to investigate the antiepileptic effects of nifedipine, an L type calcium channel blocker and BAY K8644, an L type calcium channel opener in a genetic model of absence epilepsy in WAG/Rij rats.

MATERIALS AND METHODS

Thirty two WAG/Rij rats were allocated into four groups; sham (only saline injected), only nifedipine (an L type calcium channel blocker) injected group (40 µg/2 µl; 60 µg/2 µl; 80 µg/2 µl), only BAY K8644 (1,4 Dihydro-2,6-dimethyl-5-nitro-4-trifluoromethyl- phenyl-3-pyridine carboxylic acid methyl ester) (L-type Ca2+-channel activator) injected group (40 µg/2 µl; 60 µg/2 µl; 80 µg/2 µl) and combination of their most effective doses BAY K8644 (60 µg/2 µl) after nifedipine (60 µg/2 µl) injected group. All agents were given by intracerebroventricular injection. The beta, alpha, theta and delta wave ratios of electroencephalogram recordings and the frequency and duration of SWDs (spike and wave discharges) were analyzed and compared between four groups.

RESULTS

Nifedipine increased the number and duration of spike wave discharges whereas BAY K8644 decreased both of them. When BAY K8644 was given after nifedipine, there was no significant difference with control group.

CONCLUSIONS

L type calcium channels play an activator role on spike wave discharges and have positive effects on the duration and frequency.