Female Guinea Pig Model for Cough Studies and Its Response to Most Common Tussive Substances

Methods of Cough Assessment and Objectivization

Cough is one of the most important airway defensive reflexes aimed at removing foreign particles or endogenously produced materials from the airways and provides protection against aspiration. Generally considered, cough is a vital physiological defensive mechanism for lung health. However, in case of cough dysregulation this reflex can become pathological and leads to an adverse influence on daily life. Therefore, it is necessary to effectively evaluate the severity of cough for its diagnosis and treatment. There are subjective and objective methods for assessing cough. These methods should help describe the heterogeneity of cough phenotypes and may establish better treatment by monitoring response to nonpharmacological or pharmacological therapies. It is important to keep in mind that the clinical assessment of cough should include both tools that measure the amount and severity of the cough. The importance of a combined subjective and objective evaluation for a comprehensive assessment of cough has been advocated in the guidelines of the European Respiratory Society on cough evaluation. This review article provides an overview of subjective and objective methods for assessing and monitoring cough in children and adults comparing to animal models. Key words Cough frequency; Cough intensity; Cough reflex sensitivity; Cough monitors; Cough assessment.

Modification of oestrogen signalling pathways influences cough induced by citric acid but not capsaicin in the animal model of both sexes

To clarify the role of oestrogen signalling and the role of oestrogen receptor alpha (ERα) in the cough pathways we performed a study in which coughing was observed in both sexes animal models after the treatment by selective ERα degrader fulvestrant (ICI 182-780) and inhibitor of oestrogen synthesis danazol. Degradation of ERα with the normal plasma oestrogen levels induced by fulvestrant, significantly augments the cough response of female but not male guinea pigs. These changes were observed in citric acid-induced cough. Female guinea pigs responded with an increased count of cough expulsions per challenge time and we also detected shorter cough latency. The capsaicin-induced cough did not change. A similar response was observed after danazol treatment, which decreased the plasma oestrogen level. Our results indicate that the transient receptor potential vanilloid-1 (TRPV1) channel-mediated cough is resistant to the hypoestrous state, while the citric acid-mediated cough is oestrogen-dependent and hypersensitive during the hypoestrous state.

Inhibition of inflammatory pain and cough by a novel charged sodium channel blocker

BACKGROUND AND PURPOSE

Many pain-triggering nociceptor neurons express TRPV1 or TRPA1, cation-selective channels with large pores that enable permeation of QX-314, a cationic analogue of lidocaine. Co-application of QX-314 with TRPV1 or TRPA1 activators can silence nociceptors. In this study, we describe BW-031, a novel more potent cationic sodium channel inhibitor, and test whether its application alone can inhibit pain associated with tissue inflammation and whether this strategy can also inhibit cough.

EXPERIMENTAL APPROACH

We tested the ability of BW-031 to inhibit pain in three models of tissue inflammation:- inflammation in rat paws produced by complete Freund's adjuvant or by surgical incision and a mouse ultraviolet (UV) burn model. We tested the ability of BW-031 to inhibit cough induced by inhalation of dilute citric acid in guinea pigs.

KEY RESULTS

BW-031 inhibited Na_v 1.7 and Na_v 1.1 channels with approximately sixfold greater potency than QX-314 when introduced inside cells. BW-031 inhibited inflammatory pain in all three models tested, producing more effective and longer-lasting inhibition of pain than QX-314 in the mouse UV burn model. BW-031 was effective in reducing cough counts by 78%-90% when applied intratracheally under isoflurane anaesthesia or by aerosol inhalation in guinea pigs with airway inflammation produced by ovalbumin sensitization.

CONCLUSION AND IMPLICATIONS

BW-031 is a novel cationic sodium channel inhibitor that can be applied locally as a single agent to inhibit inflammatory pain. BW-031 can also effectively inhibit cough in a guinea pig model of citric acid-induced cough, suggesting a new clinical approach to treating cough.

Gender Difference in Chronic Cough: Are Women More Likely to Cough?

Chronic cough is a common complaint for patients to seek medical cares all over the world. Worldwide, about two thirds of chronic cough patients are females. However, in some regions of China the prevalence of chronic cough between sexes is roughly the same. Estrogen and progesterone can not only have an effect on transient receptor potential vanilloid 1 channel, eosinophils and mast cells, but also influence laryngeal dysfunction, gastroesophageal reflux disease and obstructive sleep apnea hypopnea syndrome, which may lead to increased cough sensitivity in women. On the other hand, the quality of life was adversely affected more in female patients with chronic cough. Both hormones possibly cause gender difference in chronic cough.

Animal models of cough

Cough is a vital airway reflex that keeps the respiratory tract wisely protected. It is also a sign of many diseases of the respiratory system and it may become a disease in its own right. Even though the efficacy of antitussive compounds is extensively studied in animal models with promising results, the treatment of pathological cough in humans is insufficient at the moment. The limited translational potential of animal models used to study cough causes, mechanisms and possible therapeutic targets stems from multiple sources. First of all, cough induced in the laboratory by mechanical or chemical stimuli is far from natural cough present in human disease. The main objective of this review is to provide a comprehensive summary of animal models currently used in cough research and to address their advantages and disadvantages. We also want to encourage cough researchers to call for precision is research by addressing the sex bias which has existed in basic cough research for decades and discuss the role of specific pathogen-free (SPF) animals.

Various aspects of sex and gender bias in biomedical research

The main role of research in medicine is to provide relevant knowledge which, after successful translation to clinical practice, improves the quality of healthcare. The sex bias which is still present in the majority of research disciplines prefers male subjects despite legislation changes in the US grant agencies and European research programme Horizon 2020. Male subjects (cells, animals) still dominate in preclinical research and it has detrimental consequences for women's health and the quality of science. Opposite bias exists for data obtained mainly in animal models utilizing female subjects (e.g. research in multiple sclerosis, osteoporosis) with skewed outcomes for men affected by these diseases. Either way, scientists are producing results which compromise half of the population. Assumptions that females as cohorts are more variable and another assumption that the oestrous cycle should be tracked in case the females are enrolled in preclinical studies were proven wrong. Variability of male versus female cohorts are comparable and do not only stem from hormonal levels. The widespread prevalence of sex differences in human diseases ultimately requires detailed experiments performed on both sexes, unless the studies are specifically addressing reproduction or sex-related behaviors.

Various aspects of sex and gender bias in biomedical research

The main role of research in medicine is to provide relevant knowledge which, after successful translation to clinical practice, improves the quality of healthcare. The sex bias which is still present in the majority of research disciplines prefers male subjects despite legislation changes in the US grant agencies and European research programme Horizon 2020. Male subjects (cells, animals) still dominate in preclinical research and it has detrimental consequences for women's health and the quality of science. Opposite bias exists for data obtained mainly in animal models utilizing female subjects (e.g. research in multiple sclerosis, osteoporosis) with skewed outcomes for men affected by these diseases. Either way, scientists are producing results which compromise half of the population. Assumptions that females as cohorts are more variable and another assumption that the oestrous cycle should be tracked in case the females are enrolled in preclinical studies were proven wrong. Variability of male versus female cohorts are comparable and do not only stem from hormonal levels. The widespread prevalence of sex differences in human diseases ultimately requires detailed experiments performed on both sexes, unless the studies are specifically addressing reproduction or sex-related behaviors.

Legacy of Prof. Juraj Korpáš: International Impact of Slovak School of Experimental Respirology

Human health is the main role of medical research. Scientists were always intrigued by disease prevention, their diagnostics and proper treatment. In fact, research in medicine is always directed towards the improvement of the health care and improvement of the quality of life of the target population. Nowadays, physiological research, which is the base stone for clinical research, progresses fast forward, providing new information about body functions in health and diseases. This obvious progress is associated with modern methods, such as neuronal tracing, patch-clamp methods, electrophysiology, molecular biology and many more, which supported by comprehensive information technology guarantees high quality and complex data. Our younger colleagues, young scientists, post-docs or PhD students are well-trained and qualified in utilizing these new methods.