Urethral supersensitivity and occult urethral neuropathy.

The phenomenon of postural increases in urethral tone in patients with neuropathic bladder dysfunction has been investigated and, using the technique of simulated alterations in posture, a humoral response of urethral smooth muscle has been demonstrated. Serial measurements of circulating catecholamines have shown that a close correlation exists between the contraction of urethral smooth muscle and the variations in circulating catecholamines brought about as part of cardiovascular homeostasis. Identical urethral responses have been recorded in a group of neurologically intact patients who have urethral outflow obstruction, and it is speculated that these patients may have an occult urethral neuropathy.

Plasma catecholamine levels and cardiac rhythm before and after cardiac catheterisation.

Plasma catecholamine concentrations were estimated in a group of 17 fasting patients immediately before and 3 days after cardiac catheterisation. At both times electrocardiograms were recorded and blood pressures, heart rates, and respiration rates measured. Control catecholamine values were established in a group of 10 male and 10 female volunteers, bled at the same time of day under the same conditions of nutrition and posture. Levels of adrenaline and noradrenaline were increased substantially before catheterisation; 3 days later, the values were comparable to those of the control group, though still marginally higher. The increments in catecholamine levels were independent of sex and of the presence or otherwise of persistent supraventricular arrhythmias. In spite of the considerably raised catecholamine levels, electrocardiographic patterns remained unchanged, as did the other physiological values. The absence of any relation between enhanced catecholamine secretion and physiological effects is considered to be the result either of enhanced parasympathetic activity or of adaptation to a prolonged period of stress.