Effects of a pyrogen reaction on urine concentration in the dog

¹ Section of Renal Diseases, Department of Medicine, The Mount Sinai Hospital, New York City

The administration of Piromen, a pyrogenic extract, to anesthetized, dehydrated, vasopressin-supplemented dogs uniformly produced a fall in urine concentration without a significant change in solute excretion. In seven hydropenic animals, urine osmolality decreased from 1,664 to 855 milliosmols/kg and urine flow increased from 0.41 to 1.00 ml/min. In 17 animals a pyrogenic reaction was produced during a solute diuresis, in 11 during a rising or stable T^c_hh2o-C_osm relationship, and in 6 during a spontaneously falling T^c_hh2o. In the former group T^c_hh2o fell 1.9 ml/min and in the latter 3.1 ml/min. In five studies hypotonic urine was excreted. In three studies, appreciably increasing C_osm by hypertonic infusion produced a gradual decline of T_hh2o in two and no change in one. These data are interpreted as indicating that pyrogen impairs renal concentration by decreasing medullary solute content as a consequence of renal hyperemia. Alterations in distal tubular membrane permeability to water cannot be excluded.

Key Words: dog T^c_hh2o • pyrogen reaction and T^c_hh2o • pyrogen reaction and urine concentration • pyrogen and renal hyperemia • free water excretion with vasopressin • T^c_hh2o relationship • stability of C_osm with pyrogen • distal tubular hypotonicity with vasopressin • distal tubular hypotonicity with solute diuresis

Submitted on November 30, 1964