GABAB receptor (EC50 = 34 μM)

The biochemical, electrophysiological and pharmacological properties of the new GABAB receptor blocker CGP 35348 are described. In a variety of receptor binding assays CGP 35348 showed affinity for the GABAB receptor only. CGP 35348 had an IC50 of 34 microM at the GABAB receptor. The compound antagonized (100, 300, 1000 microM) the potentiating effect of L-baclofen on noradrenaline-induced stimulation of adenylate cyclase in rat cortex slices. In electrophysiological studies CGP 35348 (10, 100 microM) antagonized the effect of L-baclofen in the isolated rat spinal cord. In the hippocampal slice preparation CGP 35348 (10, 30, 100 microM) blocked the membrane hyperpolarization induced by D/L-baclofen (10 microM) and the late inhibitory postsynaptic potential. CGP 35348 appeared to be 10-30 times more potent than the GABAB receptor blocker phaclofen. Ionophoretic and behavioural experiments showed that GABAB receptors in the brain were blocked after i.p. administration of CGP 35348. This compound may be of considerable value in elucidating the roles of brain GABAB receptors [1].

CGP 35348 promotes non-REM sleep and rapid eye movement (REM) sleep and lowers high spike currents [3].

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To study the effect of CGP 35348 on learning and memory in albino mice following hypoxia ischemia insult, 10 days old albino mice were subjected to right common carotid artery ligation followed by 8% hypoxia for 25 minutes. Following brain damage, mice were fed on normal rodent diet till they were 13 week old. At this time point, mice were divided into two groups. Group 1 received saline and group 2 intrapertoneally CGP 35348 (1 mg/mL solvent/Kg body weight) for 12 days. A battery of tests used to assess long term neurofunction (Morris water maze, Rota rod and open field) along with brain infarct measurement. Overall CGP 35348 has improved the motor function in male and female albino mice but effects were more pronounced in female albino mice. In open field, CGP 35348 treated female albino mice had demonstrated poor exploratory behavior. During Morris water maze test, gender specific effects were observed as CGP 35348 had improved spatial learning and memory and swimming speed in male albino mice but had no effect in female albino mice following hypoxia ischemia encephalopathy (HIE). We concluded that GABAB receptor antagonists CGP 35348 can be used to improve gender based spatial memory. [2]

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The GABAB antagonist CGP 35348 was intraperitoneally given in doses of 100, 300, and 900 mg/kg to old rats. These rats were earlier chronically provided with EEG and EMG electrodes. Sleep recordings based on visual inspection of EEG and EMG recordings were made for 3 h post injection, and spontaneous behaviour in the recording cage was additionally observed. With 100 and 300 mg/kg, the drug produced an increase in the duration of REM sleep compared to the saline-injected control group. The REM sleep latency was correspondingly reduced. Non-REM sleep and total sleep duration increased and an s-shaped dose-response relationship was found. Explorative behaviour was diminished after injections with 100 and 300 mg/kg CGP 35348. The number and duration of spike-wave discharges were reduced after all doses of CGP 35348 and during all 3 recording hours. The latter outcomes confirm the strong suppressive action of this drug on spike-wave discharges; these effects have also been reported in models of absence epilepsy. The hypnotic properties and especially the increase in REM sleep after the administration of CGP 35348 deserve attention considering the paucity of drugs which facilitate REM sleep. The discovery of drugs promoting REM sleep might have theoretical as well as clinical consequences [3].

Animal/Disease Models: Eight male Wistar rats [3]
Doses: 100, 300 and 900 mg/kg
Route of Administration: intraperitoneal (ip) injection Results given: Compared with the control group injected with 100 and 300 mg/kg saline, rapid Eye movement sleep duration increased.

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Following weaning, mice were separated from their parents and fed on normal mouse diet until 13th week of life when they either received intraperitoneal injections of GABAB receptor antagonist CGP 35348 [(3-aminopropyl), (diethoxymethyl) phosphinic acid] at the rate of 1 mg/mL solvent/Kg body weight or saline solution for 12 days. CGP 35348 was dissolved in saline solution. [2]
Rotarod [2]
Balance and coordination in mouse was observed by using rotarod (locally manufactured) tests. It consists of a rotating drum. The drum rotated with 40 revolutions per minute. The time the animal spent on rotating drum was recorded. One pretraining trial was given to each animal. Three more consecutive trials were given to complete the experiment. The average time of these trials was obtained by using Sunyer et al.'s methods.

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Open Field (OF) [2]
A video camera attached with computational tracking system, Any-Maze, was used for observing the mice in a chamber which was 40 cm × 40 cm long and walls were 70 cm high. Ten-minute time was used for observation. For each trial the individual mouse was released in the center of the box. Distance covered, mean speed, maximum speed, time mobile, resting time, rotations, and freezing time were studied following Weitzdoerfer et al.

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Morris Water Maze (MWM) [2]
Mice were trained to swim towards platform which was hidden under the water 1.5 cm deep. By using compass North East, North West, South West, and South East locations were allocated to the pool which divided the pool into four quadrants. It was attached to computerised tracking/image analyzer system with computational tracking system Any-Maze. During the experiment the centre of the North East quadrant had the platform. 16 training trials were carried out on the mice for four days which is called spatial acquisition phase. Four training trials were taken daily and after each trial there was an interval of 15 minutes. They were allowed to search for platform for 2 minutes.The mice were kept on the platform by hand for 30 sec if they failed to find the platform after 2 min. At the end of acquisition phase, animal was tested for probe trial on the 5th day. Mice started swimming from the south start point. They were allowed maximum time of 60 sec to swim freely. After an interval of six days of the first trial of the retention phase mice received second probe trial for 60 sec. Mice were not given any trial between the 1st and 2nd probe trials according to Sunyer et al. [12]. The swimming pattern during acquisition phase was also recorded.

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Eight male Wistar rats, with body weights between 389 and 460 g and ages of about 24 months, were used. Animals lived under a 12- 12 LD cycle with white lights on at 2000 h. Red light was switched on during the dark period. Rats were implanted with a permanent tripolar EEG electrode set for recording the fronto- occipital EEG, and a bipolar electrode set for recording the nu- chal electromyogram (EMG). Rats were randomly assigned to one of four order groups of two subjects. All animals received saline, 100, 300, or 900 mg/kg CGP 35348 in four different sequences according to a Latin square design to control for order effects, so each rat received all three drug doses and the control injection. CGP 35348, solved in saline, was admin- istered IP at a volume of 2 ml/kg. The intersession interval was at least 48 h. Pharmacokinetic studies of CGP 35348 have not been performed in vivo; pharmacological data show that the EEG effects of CGP 35348 disappear in 2 to 3 h after administration. Al- though kinetics might be different in old subjects, it is not likely that it will largely exceed the half-live values of commonly used rats. Therefore, it seems safe to state that the drug effects are not likely due to the 48-h wash-out period. Moreover, in a Latin square design, order effects are counterbalanced. [3]

[1]. CGP 35348: a centrally active blocker of GABAB receptors. CGP 35348: a centrally active blocker of GABAB receptors.

[2]. CGP 35348, GABA B receptor antagonist, has a potential to improve neuromuscular coordination and spatial learning in albino mouse following neonatal brain damage. Biomed Res Int. 2014;2014:295215.

[3]. Effects of the GABAB antagonist CGP 35348 on sleep-wake states, behaviour, and spike-wave discharges in old rats. Brain Res Bull. 1996;40(3):157-62.

In summary, we used CGP 35348 to observe its effect on behavior and physiology of male and female albino mice following brain damage. We observed that overall CGP 35348 had improved the motor function in male and female albino mice but this treatment was more effective in females than in male albino mice. In open field test, female albino mice displayed poor exploratory and locomotory behavior following CGP 35348 supplementation. During Morris water maze test, we again observed the gender specific effects as CGP 35348 improves spatial learning and memory in male albino mice but had no effect on female albino mice following HIE indicating that CGP 35348 has a potential to improve neuromuscular coordination and spatial learning in male albino mice.[2]

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In conclusion, this paper reports that the GABA~ antagonist CGP 35348 enhances non-REM sleep and REM sleep and re- duces strongly spike-wave discharges. Both behavioural and EEG parameters contributed to the establishment of a hypnotic effect. The highest dose of CGP 35348 was not effective in pro- moting REM sleep. The REM-sleep-enhancing effects might have theoretical and clinical relevance.[3]

C8H20NO4P

225.2225

225.113

C, 42.66; H, 8.95; N, 6.22; O, 28.41; P, 13.75

123690-79-9

107699

Off-white to light yellow ointment

1.131g/cm3

400.5ºC at 760mmHg

196ºC

1.55E-07mmHg at 25°C

1.459

1.662

2

5

8

14

182

0

NCCCP(C(OCC)OCC)(=O)O

QIIVUOWTHWIXFO-UHFFFAOYSA-N

InChI=1S/C8H20NO4P/c1-3-12-8(13-4-2)14(10,11)7-5-6-9/h8H,3-7,9H2,1-2H3,(H,10,11)

3-aminopropyl(diethoxymethyl)phosphinic acid

Cgp 35348; 123690-79-9; Cgp-35348; CGP35348; 3-aminopropyl(diethoxymethyl)phosphinic acid; Phosphinic acid, P-(3-aminopropyl)-P-(diethoxymethyl)-; (3-aminopropyl)(diethoxymethyl)phosphinic acid; P-(3-Aminopropyl)-P-diethoxymethylphosphinic acid;

2934.99.9001

Powder      -20°C    3 years

                     4°C     2 years

In solvent   -80°C    6 months

                  -20°C    1 month

Room temperature (This product is stable at ambient temperature for a few days during ordinary shipping and time spent in Customs)

H2O : ~83.33 mg/mL (~369.99 mM)

Solubility in Formulation 1: 25 mg/mL (111.00 mM) in PBS (add these co-solvents sequentially from left to right, and one by one), clear solution; with sonication.

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 (Please use freshly prepared in vivo formulations for optimal results.)