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Biomedical subjects

W I Cranston

Publications and source records attributed to W I Cranston.

At least 55 records · Page 3Linked to original sources
PubMed1971

Local blood flow, cerebrovascular autoregulation and CO2 responsiveness in the rabbit hypothalamus.

1. Local blood flow has been measured in the hypothalamus and other areas of the brain in the conscious rabbit, by measuring the rate of clearance of small volumes (2.5-10 mul.) of a saline solution of the inert tracer (133)Xe injected locally.2. Increasing the arterial P(CO2) caused a mean rise in the hypothalamic blood flow of 34%.3. The hypothalamic blood flow remained relatively constant over a mean arterial blood pressure range of 41-140 mm Hg.4. Hypothalamic blood flow was relatively unaffected by anaesthesia with intravenous pentobarbitone; by contrast, blood flow in the cerebral cortex was greatly reduced.5. It is concluded that the technique is a valid and useful one, since CO(2) responsiveness and autoregulation is maintained. Different areas of grey matter have different flow rates, and vary in their responsiveness to barbiturate anaesthesia.

Anesthesia, General↗
PubMed1970

Acute effects of a monoamine oxidase inhibitor, tranylcypromine, on thermoregulation in the conscious rabbit.

1. The effect of a single injection of the monoamine oxidase inhibitor, tranylcypromine, administered intravenously (20 mg/kg) or into the lateral cerebral ventricle (5-10 mg), on hypothalamic and rectal temperature, has been investigated.2. Intravenous tranylcypromine causes a significant rise in body temperature, which is due, at least in part, to cutaneous vasoconstriction; this vasoconstriction is augmented by sympathectomy. It is concluded that this vasoconstrictor effect is not mediated via the central nervous system.3. Intraventricular tranylcypromine caused a transient but significant fall in core temperature. This is interpreted as being compatible with selective augmentation of hypothalamic levels of 5-hydroxytryptamine.

Animals↗
PubMed1970

The effects of salicylate on temperature regulation in the rabbit.

1. A stable pyrexia has been produced in rabbits by intravenous injection of leucocyte pyrogen followed by a continuous infusion.2. Intravenous sodium salicylate, given 4 hr after the start of pyrogen infusion, induced rapid and progressive defervescence. The rate of fall of temperature was dose dependent.3. Intravenous injection of sodium salicylate had no effect on the temperature of afebrile rabbits.4. The intraventricular injection of small doses of sodium salicylate, given 4 hr after the start of a pyrogen infusion, caused a rapid, dose-dependent defervescence, but had no significant effect on the temperature of afebrile rabbits.5. Salicylates exert at least part of their antipyretic activity through an action on the central nervous system.

Animals↗
PubMed1970

Observations on the mechanism of salicylate-induced antipyresis.

1. Fever has been produced in conscious rabbits, first, by injection of leucocyte pyrogen into the lateral cerebral ventricle and, second, by local cooling of the hypothalamus.2. Both intravenous and intraventricular salicylate produce antipyresis during an established fever due to intraventricular leucocyte pyrogen. This is incompatible with the hypothesis that salicylate acts by interfering with the passage of leucocyte pyrogen from the circulation into the hypothalamus.3. Intravenous sodium salicylate has no effect on the fever due to local cooling of the hypothalamus. This suggests that salicylates do not act on central or peripheral efferent pathways involved in thermoregulation.

Animals↗