en Respiratory Physiology/Pharmacology Respiratory Physiology/Pharmacology Experimental research article Experimental research article <p><span style="font-size:12px;"><span style="font-family:Arial;"><strong>Introduction: </strong>Histamine directly interacts with airways smooth muscles to initiate contraction. This occurs even at low concentrations among individuals predisposed to increased airway inflammation and asthma.<br /> <strong>Methods: </strong>A digital vitalograph, nebulizer, histamine, and pulse oximeter were used in this research. A total of one hundred and sixty subjects were selected and categorized into two groups; Group 1 (Test subject) and Group 2 (Control), each group contained eighty (80) subjects. Group 1 comprised occupationally exposed vulcanizers and Group 2 comprised selected students from the University of Calabar as control. Both groups comprised young male subjects of equal age (20-40 years), devoid of pre-existing respiratory disorders or on any medication(s). Demographic parameters were used to obtain sufficient information for overall analysis. Lung parameters (FVC, FEV1, PEFR, and FEV1%) were evaluated using a Vitalograph Spirometer.<br /> <strong>Results:</strong> Basal measurement showed that Group 1 had a moderate decrease in lung volumes (FVC, FEV1, PEFR, and FEV1%) of 65 subjects (representing 81.25%) and a mild decrease in 15 subjects (18.75%); all the subjects in Group 2 showed a mild decrease in lung volumes. Inhalation of histamine mist of different concentrations showed that Group 1 had a severe decrease in lung volumes of 70 subjects (87.5%) and a mild decrease in 10 subjects (12.5%). All Subjects in Group 2 showed a mild decrease in lung volumes.<br /> <strong>Conclusion: </strong>Histamine provocative test helps to evaluate asthma signs and symptoms. Airways Hyper reactiv-ity is associated with inflammation as a consequence of airway hyperreflexia. It is evidenced that associated pollutants and their chronic inhalation by the vulcanizers have a retrogressive impact on their airways which manifests with hyper response an indication for asthma signs.</span></span></p> Spirometric evaluation,Vulcanizer,Histamine,Bronchial responses 123 134 http://ppj.phypha.ir/browse.php?a_code=A-10-2241-1&slc_lang=en&sid=1 Utionkpan Linna Paul linns.paul@yahoo.com 3200319475328460038098 0000000319460675 Yes Human Physiology, University of Calabar, Calabar, Nigeria Helyn A Ikem 3200319475328460038099 3200319475328460038099 No Human Physiology, University of Calabar, Calabar, Nigeria Cecilia Peter 3200319475328460038100 3200319475328460038100 No Human Physiology, University of Calabar, Calabar, Nigeria Solomon Beshel 3200319475328460038101 3200319475328460038101 No Zoology and Environmental Biology, University of Calabar, Calabar, Nigeria