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The hypothesis that muscle chemoreflex causes subsequent vasoconstriction in renal vascular arteries due to renal sympathetic stimulation was tested by measuring arterial blood pressure and renal blood flow to the hindlimb during exercise in anesthetized dogs following denervation of the right kidney. Results showed that graded reductions in hindlimb blood flow decreases renal vasculature conductance through a process that is independent of renal sympathetic nerve activity.

Severe hypoxia for 20 min in conscious rabbits enhances the ventilation renal sympathetic nerve activity (RSNA) bradycardia and regulates blood pressure. In rabbits pulmonary receptors have little effect on the regulation of sympathetic response to viscera during severe hypoxia stress. High sensitivity to pulmonary stretch receptor input in dogs is due to pulmonary reflex regulation of sympathetic activity during hypoxia. The increased bradycardia observed in rabbits is due to increased vagal and decreased cardiac sympathetic activity.

Study of intrapericardial blocking agent injection into anesthetized dogs suggests that agents such as hexamethonium, atropine and propranolol, on injection, exhibit extracardiac effects. Atropine or propranolol affects the neural modulation of tracheal smooth muscle. Intrapericardial hexamethonium cannot subject the parasympathetic input of the heart to preferential blockade.

To determine the impact of a longer-than-average compressed workweek on police officers’ sleep, cognitive abilities, health, quality of life, and work performance, two precincts of the Phoenix Police Department participated in a 9-month, repeated-measures study. The experimental precinct worked three consecutive 13-hr 20-min (13:20-hr) shifts per week for 6 months, while the control precinct worked four 10-hr shifts per week. Officers were assessed using the Pittsburgh Sleep Quality Index, Psychomotor Vigilance Test, STROOP Color-Word test, Quality of Life Inventory, and measures of salivary cortisol. The Phoenix Police Department provided data for Professional Standards Bureau complaints, shooting qualifications, vehicular accidents, self-initiated calls, adult bookings, field interrogations, overtime, and time off for the 6 months of the study period and the same 6 months of the previous year. Self-reported caffeine intake and shift preference were also collected. Officers working 13:20-hr shifts experienced significant (p < .05) decreases in hours of sleep, overall quality of sleep, concentration, cognitive processing, and quality of life (overall and in six of eight subareas). Significant (p < .05) increases were observed in fatigue, daytime dysfunction due to sleepiness, reaction time, anticipatory errors, and Professional Standards Bureau complaints. There were no significant differences in most indices of work performance or differences due to working day or night shifts. When officers working 13:20-hr shifts returned to 10-hr shifts, all variables returned to baseline (prestudy) levels. Officers from both precincts overwhelmingly preferred 10-hr shifts. This study indicates that there are no apparent advantages but considerable liabilities associated with 13:20-hr shifts for police officers. [ABSTRACT FROM AUTHOR]