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Biomedical subjects

A Amir

Publications and source records attributed to A Amir.

67 records · Page 4Linked to original sources
PubMed1985

Effects of phencyclidine and analog drugs on acetylcholine receptor of cultured muscle cells.

Myotubes grown in culture provided a convenient experimental system for the study of the effects of phencyclidine (PCP) and analog drugs on both acetylcholine receptor (AChR) function and on its binding properties. The extent of PCP retention by these cells was studied on the same preparations. PCP, N-ethyl-l-phenylcyclohexylamine (PCE), PCP methiodide (PCPMeI), 1-[1-(3-aminophenyl)-cyclohexyl] piperidine (NH2PCP) and 1-[1-(2-thienyl)cyclohexyl] piperidine (TCP) were found to inhibit carbamylcholine (CbCh)-induced 22Na and 45Ca ion fluxes with 50% inhibition (I50) at 2-6 microM drug concentration. The I50 for CbCh-induced 42K+ efflux was 8-20 microM. Ketamine was less efficient with an I50 of 100 microM. Binding of [125I] alpha-bungarotoxin [( 125I]alpha-BGT) was not affected at drug concentrations that cause 100% inhibition of ion fluxes. Retention of [3H]PCP by the myotubes was a saturable process with half-maximal saturation at approximately 20 microM PCP. It was inhibited by PCP and several tertiary analogs, with and I50 of approximately 20 microM. PCPMeI was much less effective, with an I50 of 1 mM. PCPMeI was, however, as potent as PCP in its inhibition of the AChR function although the amount retained by the cells was 50-fold lower than that of PCP. These results are consistent with the theory that PCP and analog drugs affect AChR at a site other than the alpha-BGT binding site, possibly at the ionic channel of the nicotinic receptor.

Animals↗
PubMed1984

N-allyl analogues of phencyclidine: chemical synthesis and pharmacological properties.

Several N-allyl derivatives of 1-phenylcyclohexylamine (PCA) were prepared, and their pharmacology was briefly characterized. The mono- and diallyl derivatives had phencyclidine-like activities in mice but were less potent behaviorally than phencyclidine (PCP). None were PCP antagonists. In vitro these compounds were competitive inhibitors of butyrylcholinesterase (BChE) and protected against inhibition by DFP. In addition, these agents displaced tritiated N-methyl-4-piperidyl benzilate from mouse-brain homogenates and inhibited the effects of acetylcholine on isolated guinea pig ileum. None of these in vitro effects correlated with their PCP-like behavioral activity in vivo in mice.

Animals↗
PubMed1983

Synaptogenesis and myelination in dissociated cerebral microcarrier cell cultures.

A new approach for cultivating dissociated cerebral neurons is described. It is based on a rapid attachment of neurons to the DEAE-cellulose cylindrical MC and their subsequent interconnection to form cell-MC conglomerates. Intensive fiber growth followed by synaptogenesis and progressive myelin formation are indicative of optimal conditions of nutrition and oxygenation.

Acetylcholinesterase↗
PubMed1983

Cultures of central neurons grown in the presence of phencyclidine.

In order to study the mode of action of phencyclidine at the cellular level differentiating cultures of dissociated nerve cells from brain and spinal cord have been used. Cells were grown in the presence of 50-500 microM of PCP or tritium labelled PCP, for the periods of 1-11 days. PCP in the concentration of 500 microM caused progressive degeneration of nerve cells, already noticeable after 24 h. No significant morphological changes were observed in cells exposed to PCP at concentrations up to 200 microM. In brain cultures exposed to 200 microM PCP, 50% decrease of AChE activity was observed. No decrease in enzyme activity was found in cultures of spinal cord.

Acetylcholinesterase↗
PubMed1983

Neuronal cultures on microcarriers: dissociated spinal cord cells.

Dissociated spinal cord cells from rat fetuses were successfully cultured up to the state of synaptogenesis and myelin formation on DEAE cellulose cylindrical microcarriers. Nerve cells and microcarriers interconnected to form conglomerates offering optimal nutritional conditions which enhanced cell maturation. These conglomerates yielded large amounts of cells which could easily be harvested for biochemical analysis.

Animals↗
PubMed1983

Walking cane designed to assist partial weight bearing.

The device described indicates accurately the amount of weight borne on an affected leg. This device consists of two major elements: a weight measuring system incorporated in the walking cane's body, and a feedback mechanism situated in the cane's handle. By means of vibration or lights the patient and the therapist can determine whether or not the affected leg is bearing the prescribed weight. Thirty patients (10 with fractures, 10 with vascular disorders, and 10 below-knee amputees) and 10 healthy people participated in the study. The study concluded that young patients used the feedback information more readily than older patients. The intention in designing such a device is to help orthopedically disabled patients during their convalescence, to minimize strain on ischemic legs, and to assist amputees in monitoring weight-bearing postoperative walking.

Adolescent↗
PubMed1982

Interaction of phencyclidine with mouse neuroblastoma cells.

Growth of mouse neuroblastoma (Nb) cell (clone M1) was not affected by phencyclidine (PCP) concentrations of 10(-6)M up to 2 x 10(-4)M, whereas 10(-3)M PCP caused a 100% inhibition of cell growth. Several PCP analogs, including the quaternary PCP methiodide, exerted effects similar to those of PCP. The uptake of [piperidyl-3,4-3H]PCP ([3H]PCP) by the Nb cells was studied using cell monolayers in Petri dishes. Non-specific entry of PCP into the cells was linear with added substrate but specific uptake exhibited saturation kinetics. The concentration for half-maximum specific uptake was 2 x 10-(5)M, and the capacity of the cells at saturation was 2-3 nmoles [3H]PCP/mg protein, at 22 degrees. The uptake rate constant was 0.2 +/- 0.05 x 10(5) (M-1 min-1) and the dissociation constant was 0.25 +/- 0.05 (min-1). Uptake was temperature dependent and was inhibited by 2,4-dinitrophenol (DNP). This may indicate that this binding represents (at least in part) an active uptake process of PCP into the cells.

Animals↗
PubMed1980

The effect of phencyclidine on noradrenaline uptake by bovine chromaffin granules.

The effects of the psychotomimetic drug, phencyclidine, on the reserpine sensitive uptake of (-)noradrenaline, on the reserpine resistant uptake of tryptamine, and on catecholamine release were studied in vitro using bovine chromaffin granules. Phencyclidine inhibited the uptake of (-)noradrenaline and tryptamine in a concentration-dependent manner. It caused 50% inhibition of (-)noradrenaline uptake at 2 X 10(-4)M and of tryptamine uptake at 7 X 10(-4)M. Release of catecholamines was not affected by phencyclidine at 0 degree C and pH 6--8 in concentrations up to 8 X 10(-3)M, whereas at 37 degrees C the drug (4 X 10(-3)M) caused a release that was increased when the pH was raised from 6 to 8. Since the effects of phencyclidine on chromaffin granule uptake and release are observed at high concentrations of the drug only, there is no evidence that these effects are relevant to the in vivo effects of the drug.

Animals↗