The effect of the GABAA antagonists, bicuculline and picrotoxin, in the hot plate and writhing tests in mice and the paw-pressure test in rats was assessed. Subconvulsant doses of bicuculline (1.3-4 mumol kg-1, s.c.) or picrotoxin (0.8-2.5 mumol kg-1, s.c.) induced a dose-related increase in latency of licking in the hot plate test in mice, whereas subconvulsant doses of strychnine and thiosemicarbazide (0.9 and 6 mg kg-1, s.c. respectively), did not modify the threshold to thermal stimuli in mice.
RATIONALE: A recent in-vitro study demonstrated that the potent disulfide reducing agent, DL-dithiothreitol (DTT), may alter the structural stability of the GABA(B) receptor, probably inactivating the disulfide bonds between four cysteine residues located in the GABA(B1(a)) receptor structure. OBJECTIVES: The present study was designed to evaluate whether DTT treatment was capable of antagonizing some behavioral effects of pharmacological stimulation of the GABA(B) receptor.
The present study investigated whether the differential sensitivity of selectively bred gamma-hydroxybutyric acid (GHB)-sensitive (GHB-S) and GHB-resistant (GHB-R) rats to GHB- and baclofen-induced sedation/hypnosis generalized to the motor incoordinating effect of the two drugs. To this aim, GHB-S and GHB-R rats were tested on a Rota-Rod after the acute administration of GHB (100-500 mg/kg, i.p.) and baclofen (1.25-5 mg/kg, i.p.).
Gamma-hydroxybutyric acid (GHB)-sensitive (GHB-S) and GHB-resistant (GHB-R) rats have been selectively bred for their opposite sensitivity to the sedative/hypnotic effect of GHB. This opposite sensitivity has been found to generalize to the GABA(B) receptor agonist, baclofen. A control line [named GHB-control (GHB-C)] has been derived from the foundation stock of GHB-S and GHB-R rats. GHB-C rats have been bred without any evaluation of their sensitivity to GHB.
Two recently reported hit compounds, COR627 and COR628, underpinned the development of a series of 2-(acylamino)thiophene derivatives. Some of these compounds displayed significant activity in vitro as positive allosteric modulators of the GABAB receptor by potentiating GTP?S stimulation induced by GABA at 2.5 and 25 ?M while failing to exhibit intrinsic agonist activity. Compounds were also found to be effective in vivo, potentiating baclofen-induced sedation/hypnosis in DBA mice when administered either intraperitoneally or intragastrically.
In this case study we describe a dual approach to the palliation of difficult muscle spasms using intrathecal baclofen via a fully implanted system, together with the homeopathic approach to symptom control. The homeopathy is seen to complement rather than to replace conventional prescribing and using both approaches together appears to have avoided the necessity for increasing drug doses and to have minimized side-effects.
Compendium of Continuing Education in Dentistry (Jamesburg, N.J.: 1995)
The purpose of this article is to give a concise review of the diagnosis and management of trigeminal neuralgia (TN), with particular emphasis on idiopathic TN and symptomatic TN. The clinical characteristics of both conditions are presented, and the suspected underlying etiologies are discussed. Because it is crucial for clinicians to be able to rule out pain unrelated to TN, a list of differential diagnoses is presented. The authors stress that the diagnosis of TN is made clinically; however, diagnostic imaging may be indicated in selected cases.
The possible mechanism of electroacupuncture (EAc) in reference to the effects of neuropeptides on serotonergic neurons in rat spinal cord was studied. The tested drugs were administered by intrathecal injection or spinal push-pull perfusion. The results showed that baclofen, substance P (SP) and naloxone administered intrathecally could reduce the tail pressure pain threshold. The pain threshold was increased by met-enkephalin (EK) and EAc. The action of EAc was antagonized by naloxone.