Study of the effects of L-dopa on some chemical transmitters in CNS in normal and liver diseased animals

The influence of intraperitoneal administration of L-dopa on brain chemical transmitters and liver function tests was investigated in rats with paracitamol induced hepatic necrosis. It was found that L-dopa produced a significant increase in the level of norepinephrine and a significant decrease in the level of epinephrine and serotonin. On the other hand, L-dopa did not improve the histopathological picture of the liver and the liver function tests of the diseased animals. These data indicate that the improvement in the clinical picture of hepatic coma by injection of levodopa could be explained by its effect on the neuro-hormonal transmitters and not due to direct action on the liver

Effect on interaction between clonidine and calcium channel blockers on vascular smooth muscles

The 2 alpha receptor triggered vasoconstriction appears to be largely dependent upon the influx of extracellular calcium ions. This study was conducted to study the interaction between calcium channel blockers [nifedipine and isradipine] and clonidine.Mongrel dogs were used to study this interaction on the blood pressure nifedipine and isradipine attenuated the effect of clonidine on the blood pressure. When dogs were subjected to bleeding, it was found that nifedipine and isradipine also attenuated the effect of clonidine on the blood pressure of dogs.Using Abino rat hind quarter preparations, it was found that nifedipine and isradipine produced significant increase in the vascular outflow rate. The effect of isradipine was more significant than that of nifedipine. Clonidine non- significantly decreased the vascular outflow rate nifedipine and isradipine significantly attenuated the vasoconstrictor response to clonidine and this should be taken in consideration if a subject under nifedipine or isradipine treatment needs alpha 2-stimulants for treatment of emergency hypotensive states

Natural honey as potential diuretic, [experimental study]

In this study the potential diuretic effect of honey was investigated in anaesthatized dogs and compared to hydrochlorothiazide as a standard diuretic drug. Intravenous administration of honey 1 gm/k gm in a 40% dilution in normal saline produced significant augmentation of volume of urine output, urine sodium, chloride and to less extent potassium excretion. The increase in cation excretion is covered with commonsurate increase of chloride ion i.e. chloride ions appears to be the main attending anion. The diuretic effect of honey starts immediately after administration and reaches maximum after 20 to 40 minutes. The pattern of diuretic effect of honey as well as the magnitude of this effect, compare favourably with the response to hydrochlorothiazide [2.5 mg/kgm I.V]. However, honey has the advantage that it produces less kaliuresis. Measurement of serum concentration of sodium, chloride and potassium following administration of honey or hydrochlorothiazide revealed that concentrations of these ions are not altered except the potassium concentration which shows mild hypokalaemia in dogs treated with hydrochlorothiazide. A mixture of glucose-fructose - sucrose - maltose [GFSM] in the same proportions as they are found in honey was tested in a group of dogs in a dose of 1 gm/kgm i.e. equal to the o dose of natural honey, this mixture failed to produce any diuretic effect. Such finding could suggest that the diuretic effect of honey is not attributed to its sugar content. Although the various mechanisms of action or the site of the diuretic effect at the nephron have not been elucidated, this is the first study which provides a controlled scientific evidence for the potential diuretic effect of honey. These preliminary results suggest that honey may be used clinically as a safe diuretic. However, further investigations are required to explore the mechanism [s] of this property and fully to ascertain it's clinical potential