WATER-SOLUBLE COOLING LUBRICANTS INDUCE AIRWAY HYPERRESPONSIVENESS INRABBITS

Airway hyperresponsiveness (AHR) to water-soluble cooling lubricants ( CL) induced by aerosol administered by tracheal tube was studied in a rabbit model of occupational lung disease. Two commercial GL were exam ined: the first was of the boric acid amine ester type without biozide (CL-BAE), the second was of the sulfonate type with biozide (CL-SB). 50, 5.0 or 0.5 mg/m(3) GL was administered over a period of twice 2 h to six different groups of rabbits. Airway responsiveness (AR) to aero sols of 0.2% and 2.0% acetylcholine solution (ACH) was measured before and after each exposure to CL. A control group A of nine animals not exposed to CL showed no significant respiratory responses following in halation of 0.2% AGH for 1 min. Conversely, inhalation of 2.0% AGH alm ost doubled the dynamic elastance (E-dyn) in the ACH challenge test in this animal group. Airway resistance (R-1), E-dyn, Slope of inspirato ry pressure generation (Delta P-es/t(I)), arterial pressure (P-a) and arterial blood gas tensions (PaO2, PaCO2) were not significantly alter ed during and after exposures to GL, However, after CL-BAE inhalation of 50 and 5 mg/m(3) over 4 h, the amplitude of the AGH-induced airway obstruction indicated by the changes in E-dyn rose significantly to al most five times the control response before exposure (group C, D, p < 0.005), Similar changes in R-I and Delta P-es/t(I) were obtained. Afte r inhalation of 0.5 mg/m(3) CL-BAE (group D), no significant changes i n AR were observed. Similar to CL-BAE inhalation of 50 mg/m(3), CL-SB caused enlarged AR in the AGH challenge test (group E), whereas no sig nificant changes were found after exposure to 5.0 and 0.5 mg/m(3) in g roups F and G. In summary, CL aerosols with and without biozide in the range of 50 and 5 mg/m(3) applied via tracheal tubes increased AR to ACH within 4 h of exposure in a time-and concentration-dependent manne r. It has to be assumed that this augmented AR indicates an increased risk of developing lubricant-induced obstructive lung diseases.