Brain Serotonin Metabolism and Δ9-Tetrahydrocannabinol-Induced Muricide Behavior in Rats

Abstract

-Using the redox potential of the myocardium (JFh) as a measure of the myocardial energy metabolism. the rnctaholie effects of three representative catechol amines, adrenaline (Adr). noradrenaline (Nor) and isoproterenol (Isp) were studied, in the canine heart-rung preparation supported by a donor. Adr and Nor produced an initial improvement of JLh, followed by a sustained debasement, while Isp produced only a debasement.Pretreatment of the preparation with phentolamine or dibenamine, resulted in an abolishment of the initial irniproscmcnt, while the efhect of Isp remained unchanged.After pretreatment of the preparation with practolol, the positisc inotropic and chronotropic effect and the associated increase in the myocardial oxygen con sumption were no longer seen w th all the catecholamines tested. Under these con ditions. Adr and Nor produced a sustained improvement of JLh, while Isp produced a transient debasement, sshich, in turn" was abolished by propranolol.A\ hen tile heart was dris en at a constant rate, the myocardial oxygen consumption did not increase with the catecholamines in most of the case and a sustained improvement of JEh was observed with Adr and Nor: Isp produced a transient debasement.These findings indicate that catecholamines produce an improvement of the myocardial energy me tabolism through act is ation of the adrenergic n-receptor.

Effects of treatment with a 5‐HT4 receptor antagonist in heart failure

“…5‐HT 4 stimulation increases cardiomyocyte cAMP content in the rat failing ventricle ( Qvigstad et al ., 2005a ), and increased protein kinase A activity in porcine ventricle ( Brattelid et al ., 2004b ). cAMP is known to increase cellular energy consumption, as indicated by the effects of β ‐adrenoceptor stimulation on myocardial energetics ( Otorii et al ., 1977 ; Hasenfuss et al ., 1989 ). This is critical because the energy production in the failing heart is probably limited ( Spindler et al ., 2003 ).…”

Effects of piridoxilate, a glyoxylic acid derivative, on the energy metabolism of the heart.

“…Experiments were performed on the canine heart-lung preparation supported by a donor (HLP c donor) ( Fig. 1), the details of which were described in previous publications.11), 14) Mongrel dogs of either sex weighing between 7 and 13Kg were anesthetized with sodium pentobarbital (35mg/Kg) injected intraperitoneally.…”

“…The pyruvic acid determinations were conducted as described in Jpn. Heart J. N ovember, 1980 a previous paper (Otorii et al, 1977). In order to record the oxidation-reduction state of the pyridine nucleotides within the cell continuously, an organ redoximeter, constructed on the basic principle developed by Chance et al2) and equipped with an analog computer which compensated for a "hemodynamic artifact"13) (Tateishi OMRON Electronics Co HEF-4), was used.…”