[Clinical evaluation on antagonistic effects of tolazoline on xylazine Hcl in calves]

To determine the antagonistic effects of tolazoline on xylazine Hcl sedation, 12 male Holstein calves of 8 to 12 months age with an average weight of 210 Kg were considered and arranged in 2 groups of 6 calves as the test and control groups. All calves were received an initial IM injection of xylazine Hcl [0.4 mg/Kg of 2% solution] followed in 15 minutes by IV injection of Tolazoline [2 mg/Kg of 10% solution] in test group and IV injection of the same volume of 0.9% normal saline in control calves. The significance reversal effects of tolazoline for xylazine Hcl on rectal temperature, heart and respiratory rates and recovery time [9.67 +/- 0.7 minutes] [P<0.05] indicated that, tolazoline is potentially enable to diminish the undesirable effects of xylazine Hcl such as prolonged sternal recumbancy with minimal complications

Urinary bladder serosal chemoreceptor induced cardio-respiratory responses: possible pathway.

There is limited experimental information about pain originating from the urinary bladder. In the present study application of 3-5 ml of 1% ammonium oxalate, 1% potassium chloride, 100m M citric acid, IM ammonium chloride, 1% oxalic acid, 0.5% sodium hydroxide, or 2 micrograms/ml bradykinin, to the serosal surface of the urinary bladder in anaesthetized dogs, resulted in an increase in heart rate, rise of both systolic and diastolic blood pressures and increase in respiratory rate and depth. These facilitatory cardio-respiratory responses were coupled with powerful contractions of the urinary bladder wall. By contrast, mucosal application of the chemicals did not bring about any significant change. The cardio-respiratory responses obtained were completely abolished on serosal application of procaine (1%), section of the hypogastric nerves or by spinalectomy at T8. Bilateral cervical vagotomy and pelvic nerve section did not modify the responses. However, the blood pressure responses were abolished by the administration of tolazoline hydrochloride, indicating a major role of sympathetics in this nociceptive reflex.

Effect of adrenergic and cholinergic antagonists on post-hemorrhagic erythropoiesis in rats.

Experiments were carried out in albino rats to find out the effect of propranolol, priscol and atropine on post-hemorrhagic erythropoiesis. Administration of either propranolol or priscol decreased reticulocyte response following hemorrhage, whereas administration of atropine produced no change. The results indicate that alpha as well as beta adrenergic systems participate in the control of erythropoiesis following hemorrhage, whereas parasympathetic system does not take part.