A rapid procedure for the analysis of phenylalanine in brain tissue utilizing electron-capture gas chromatography

A rapid procedure has been developed for the analysis of phenylalanine in brain tissue. Perchloric acid extracts of brain tissue were made basic, and benzoyl chloride was added to derivatize the amine function. The aqueous layer was retained and made slightly acidic. To derivatize the carboxylic acid group, a solution of pentafluorobenzyl alcohol was added in the presence of the coupling agent dicyclohexylcarbodiimide and chloroform. After shaking for 15 min, the organic phase was retained and taken to dryness. The residue was taken up in toluene, washed, and an aliquot used for analysis on a gas chromatograph equipped with an automatic injector, a capillary column and an electron-capture detector. The procedure has been utilized for analysis of phenylalanine in brains of rats treated with vehicle or phenylalanine.     

case report: Ovarian stimulation in an infertile patient with growth hormone-deficient Oliver-Mcfarlane syndrome

Several authors have suggested that growth hormone may augmentovarian responses to follicle stimulating hormone in women (Homburget al., Clin. Endocrinol., 29, 1988; Ibrahim et al., Fertil.Steril., 55, 1991), and that this effect may be mediated byinsulin-like growth factor I (IGF-I) (Davoren and Hsueh, Endocrinology,118, 1986). Menashe et al. (Hum. Reprod., 6, 1991) reportedspontaneous pregnancies in women with a deficiency in growthhormone receptors and, consequently, low serum concentrationsof IGF-I. In this report, we present the case of a patient witha rare syndrome first described by Oliver and Mcfarlane (Arch.Ophthalmol., 74, 1965). The patient was shown to be growth hormonedeficient, with hypopituitarism as part of the syndrome. Adjuvantgrowth hormone did not influence her ovarian responses to exogenousgonadotrophins during assisted conception treatment, as reflectedby the required total number of ampoules of human menopausalgonadotrophin, the number of developing follicles, the rateof follicular growth and the serum oestradiol concentrations.     

IMAGES IN CARDIOLOGY: LEFT VENTRICULAR FREE WALL RUPTURE

Left ventricular free wall rupture is thought to account for approximately 15% of deaths following acute myocardial infarction (MI). We present a case of left ventricular free wall rupture in a 64-year-old man following a lateral MI. The diagnosis was made with 2D and colour flow Doppler echocardiography. Unfortunately the patient died before emergency surgery, could be performed.     

Tissue levels and some in vivo responses to a monofluorinated analogue of amphetamine in the mouse

The metabolism and some behavioral properties of each of the optical isomers of 2-amino-1-fluoro-3-phenylpropane hydrochloride (fluoroamphetamine, FAM) were examined and compared to those of the optical isomers of amphetamine (AM). Substitution of fluorine into the side-chain of AM increased the rate of elimination of drug from brain and modified the kinetics from a one- to a two-compartment model. Urinary excretion of unchanged S-(-)-FAM was reduced from that observed after R-(-)-AM, suggesting a more extensive metabolism. Fluorine substitution also modified the behavioral response to AM. Thus, each optical isomer of FAM produced paradoxical reductions in locomotor activity and body temperature.     

Brain levels of 5-hydroxytryptamine, tryptamine and 2-phenylethylamine in the rat after administration of N-cyanoethyltranylcypromine

1. Brain levels of 5-hydroxytryptamine (5-HT), tryptamine (T), 2-phenylethylamine (PEA) and monoamine oxidase activity at 5, 15, 30, 60, 120 and 240 min were determined in male Sprague-Dawley rats after intraperitoneal injection of the “pro-drug” N-2-cyanoethyltranylcypromine (CE-TCP, dose 0.1 mMole/kg).

2. Analyses of 5-HT, T and PEA were performed on an electron-capture gas Chromatograph with a capillary column. Activity of MAO-A and MAO-B was measured using a radiochemical method.

3. Results indicate substantial inhibition of MAO in rat brain after intraperitoneal administration of CE-TCP, leading to elevated levels of 5-HT, T and PEA as early as 5 min after drug administration.

4. Increases in brain levels of the trace amines T and PEA were much greater (approximately 40 and 100 times control levels, respectively) than with 5-HT (approximately 1.8 times control level) 240 min after administration of CE-TCP.