ABSTRACT
This study investigates the effects of antinerve growth factor (anti-NGF) application on isolated ileal contractility in the rat. For this purpose, rats were divided into four groups. The control animals (n=8) received only intraperitoneal injection of an isotonic NaCl solution (i.p). Anti-NGF was daily administered intraperitoneally at the dose of 1 ng/g level in the first experimental group (n=8), and at doses of 10 ng/g (n=7) and 40 ng/g (n=7) in the second and third experimental groups, respectively. Seven days after the injections rats were sacrificed and ileum segments were isolated. Responses to acetylcholine (ACh) were evaluated by using standard Tyrode, double-calcium Tyrode and calcium-free Tyrode solutions. The average peak amplitude of ACh-induced contractions recorded in standard Tyrode solution was significantly decreased in all three experimental groups as compared to the control group (p 0.05). When double-calcium Tyrode solution was used as the perfusion medium, the responses to ACh were also lower in all anti-NGF applied groups as compared to its control group (p 0.05). Our results showed that the application of anti-NGF reduced the contractile responses of the rat isolated ileum apparently by decreasing the calcium influx from the extracellular medium.
Subject(s)
Ileum/drug effects , Ileum/physiology , Muscle Contraction/drug effects , Muscle Contraction/physiology , Muscle, Smooth/drug effects , Muscle, Smooth/physiology , Nerve Growth Factor/immunology , Animals , Antibodies/administration & dosage , Dose-Response Relationship, Drug , Female , Gastrointestinal Motility/drug effects , Gastrointestinal Motility/physiology , Injections, Intraperitoneal , Male , Rats , Rats, WistarABSTRACT
The aim of the study was to investigate the acute and chronic effects of hyperoxygenation on platelet aggregation and adenosine triphosphate (ATP) release. To observe the acute effects of hyperbaric oxygen (HBO2), seven New Zealand rabbits were exposed to 2.4 atm abs oxygen for 90 min (group 1). Eight other rabbits were further exposed to O2 daily for 20 days (group 2) to observe the chronic effects of HBO2. Adenosine diphophate (ADP) and collagen-induced platelet aggregation and ATP release were evaluated before and after oxygenation in groups 1 and 2. It was found that the maximal rate of ADP and collagen-induced platelet aggregation decreased after hyperbaric oxygenation in group 1. No significant alteration was observed in platelet responses at the end of 20 days of oxygenation in group 2. The adaptation of platelets of 2.4 atm abs O2 after 20 days of exposure seems to need further investigation.
