Pharmacological and Biochemical Effects of 5-Hydroxytryptamine in Adrenalectomised Rats

Abstract

In adrenalectomised rats 5-hydroxytryptamine induces a fall of temperature and blood pressure which is more marked than in intact animals. This hypersensitivity is not related to changes in tissue monoamine oxidase or serum ceruloplasmin. Administration of 5-HT raises the levels of tissue 5-HT in adrenalectomised rats to the same extent as in control rats.

The Effect of 5-Hydroxytryptamine on the Cotton Pellet Local Inflammatory Response in the Rat

“…A major deterrent to speculation relating this finding in rats to fibrosing reactions in man is the very large doses of 5-HT required to produce these effects in the rat. The effective dose of 5-HT is well within the reported J-950 in rats using subcutaneous routes (115 mg/kg) (23,31,32), although minimal level tubular dilatation has been noted when this dose is given over 10 days. Higher doses may cause significant renal damage (15,33,34).…”

“…Another complicating factor is that adrenalectomized rats are more sensitive to the hypotensive and hypothermic effects of 5-HT. While these effects are marked at doses higher than those used in our experiment, moderate effects have been noted at 10 mg/kg (23). The adrenalectomized rats in the present study appeared grossly to tolerate 10 mg/kg as well as control rats.…”

“…The effects of 5-HT on granuloma and thymus weights in adrenalectomized rats are summarized in Table V. An additional dose of 5-HT (3 mg/kg) was studied since adrenalectomized rats have been reported to be more sensitive to the toxic effects of 5-HT than control rats (23), but the adrenalectomized rats in the present study tolerated 5-HT up to and including 10 mg/kg well. 5-HT (1 mg/kg and 3 mg/kg) failed to alter significantly either granuloma weight or thymus weight from control levels.…”

Some factors influencing the release of 5‐hydroxyindol‐3‐ylacetic acid in the forebrain

“…Thus our results are in accordance with experimental data reported by Towne & Sherman (1960), Garattini, Lamesta, Mortari, Palma & Valzelli (1961), Resnick, Smith & Gray (1961) and Pfeifer, Vizi, Satory & Galambos (1963). ( Fig.…”