Straub tail reactions

An assay procedure based on the Straub tail reaction in mice has been shown to be capable of ranking the activities of both agonists and antagonists, results which are consistent with previous estimates [241]. 

A significant discovery came about in 1939 at the laboratories of Farbenindustrie (Germany), during the investigation of antispasmodic medications related to atropine. At this time, Schaumann [60] examined a compound synthesized by Eisleb for in-vivo antispasmodic activity, and observed a Straub tail reaction which was usually associated with the centrally exciting component of opioid activity. This... 

The initial report of the potent biological activity of 112 generated a great deal of interest. Epibatidine was found to be 200 times and 500 times more potent than morphine in causing hot plate analgesia and in eliciting a Straub-tail reaction, respectively. It had a very low affinity for opioid receptor sites, which suggested an alternate mechansim of action was involved [322]. 

Papaverine does not cause deep narcosis or marked analgesia. It may produce convulsions, and cause the Straub tail reaction. The excitability of isolated nerves and muscles is abolished. Respiration is not profoundly affected. A single injection in rabbits causes an increase in blood sugar which is cancelled out by adrenalectomy or by a repetition of the injection over a period of days. Hyperglycemia follows withdrawal. 

DilAienylpropylamines emd Miscellaneous thiophthalanes studied for analgesic activity,-most active. It was approximately equal to morphine (mice, hot-plate, tail-pinch and Mlsen tests), produced a Straub-tail reaction and was antagonized by nalorphine. Similar thiophthalanes with a propylamlno side chain had been previously studied as antidepressants, but were not analgesics and did not produce a Straub-tall. 

Precipitation reactions for the detection of morphine have been recorded [215-38 inc.]. In the Straub biological test as little as 0-01 mg. of the alkaloid injected subcutaneously on the back of a white mouse causes the animal to lay its tail over its back [239]. Other methods for the detection of morphine [240-4] and of its diacetyl ester (heroin) [228-30, 233-4, 242, 245-6] are known. 

---