PREGANGLIONIC AND POSTGANGLIONIC STIMULATION OF THE GUINEA-PIG ISOLATED VAS DEFERENS PREPARATION

The isolated vas deferens of the guinea-pig contracted when stimulated transmurally with parallel wire electrodes. These contractions persisted in concentrations of hexamethonium, pentolinium, nicotine and mecamylamine which at the same time abolished the responses to hypogastric nerve stimulation. Procaine and lignocaine in local anaesthetic concentrations abolished the responses to transmural stimulation but potentiated the contractions produced by added noradrenaline. Guanethidine and bretylium in concentrations specific for adrenergic neurone blockade abolished the contractions due to transmural stimulation without impairing the responses of the muscle to added noradrenaline or acetylcholine. In contrast, high concentrations of the adrenergic-blocking agents phentolamine and dihydroergotamine were needed to block the contractions due to transmural stimulation; these concentrations also blocked the response to added noradrenaline but simultaneously reduced the responses to added acetylcholine or potassium chloride. Preparations from guinea-pigs previously treated with reserpine at first responded normally to transmural stimulation; thereafter the contractions diminished progressively but were never abolished. Hyoscine and atropine produced a small decrease in the response to transmural stimulation when present in concentrations up to 1x10(-5) and a larger decrease only in concentrations of 1x10(-4) or greater. Hemicholinium produced a small decrease of the contractions due to transmural stimulation in concentrations up to 1x10(-4); concentrations of 5x10(-4) present for 1 hr produced only a slightly greater reduction in response. These experiments show that when the guinea-pig vas deferens is removed without the hypogastric nerve and stimulated transmurally by the method described, contractions are produced mainly by excitation of postganglionic adrenergic nerves.

LEAKAGE OF TRANSMITTERS IN SALIVARY GLANDS

Salivary secretion evoked by sympathetic stimulation or by injection of guanethidine, adrenaline or synephrine is slightly reduced by parasympathetic antagonists in doses which abolish the secretory responses to stimulation of the parasympathetic nerve. Similarly, an adrenaline antagonist caused a small diminution of the salivary flow elicited by parasympathetic stimulation or by injection of methacholine chloride. Secretion caused by pilocarpine could be accelerated by physostigmine. We conclude that transmitter leaks in subliminal concentrations, as far as secretion is concerned, from the sympathetic and parasympathetic postganglionic nerve endings.

Effect of isocarbacyclin methyl ester incorporated in lipid microspheres on experimental models of peripheral obstructive disease

The effect of TTC-909 (isocarbacyclin methyl ester (CAS 88931-51-5, TEI-9090) incorporated into lipid microspheres) on obstruction of the peripheral artery was studied in two different animal models. The first was a peripheral occlusion model induced by intra-arterial injection of sodium laurate in rats. The second was a tail gangrene model induced by subcutaneous injection of both ergotamine and epinephrine in rats. Intravenous bolus-administered TTC-909 at 1.0 microgram/kg resulted in the inhibition of both progression of lesions induced by sodium laurate and the extension of tail gangrene by ergotamine and epinephrine. Moreover, the inhibitory effect of TTC-909 was more potent than that of PGE1 (LM) (prostaglandin E1 incorporated into lipid microspheres). These findings suggested that TTC-909 may be clinically useful for the therapy of peripheral vascular disorders such as thromboangiitis obliterans (TAO) and atherosclerosis obliterans (ASO).

MMPI and critical flicker frequency (CFF) analysis in headache patients with and without drug abuse

Sixty-three headache patients (migraine: n = 28; tension-type headache: n = 35) who fulfilled the IHS criteria of 'drug abuse' were investigated by means of the Minnesota Multiphasic Personality Inventory (MMPI) and the Critical Flicker Frequency (CFF) analysis. The results were compared to those of 63 headache patients without drug abuse (matched-pair case-control study). With respect to the MMPI results, no statistically significant differences between patients with drug abuse and patients without drug abuse were found. However, patients with drug abuse showed significantly decreased CFF values compared to patients without drug abuse. This was true both for patients with migraine and for patients with tension-type headache. Thus, CFF analysis may serve as a useful method to differentiate between headache patients with drug abuse and those without drug abuse.

Denial of hospitalization by insurers for inpatient treatment of medication rebound headaches

Inpatient treatment with intravenous dihydroergotamine has been remarkably successful in managing chronic daily headaches due to excessive use of analgesics or ergotamine tartrate. Recently we have been denied authorization in appropriate patients for this procedure by third party payers on the grounds that it was "not medically necessary," "based on anecdotal information," or is "an outpatient procedure." Three cases are described in which the insurer's decision was either contested as an issue of substandard care, or the patient elected to pay for the procedure. The outcome in two cases was dramatically favorable, at least from the patient's and the physician's point of view. The third case is currently being appealed. Time and energy spent on combating the position of the third party payer on issues of standards of specialist care should be unnecessary. Publication of standards of care by specialists, and a requirement that these care standards must be provided by third party payers are needed in order that quality medical care can continue in this society.

Mitral valve disease associated with long-term ergotamine use

A 43-year-old woman with symptoms and signs of congestive heart failure and intermittent claudication was found to have moderately severe mitral stenosis and regurgitation, as well as severe bilateral upper and lower extremity arterial occlusive disease. She had a history of migraine headaches and had abused ergotamine tartrate (Cafergot) chronically for more than 20 years. Only rare instances of valvular heart disease have been associated with chronic ergotamine toxicity, with the majority of previously reported cases based on auscultatory findings alone.