Respiratory responses to microinjections of leptin into the solitary tract nucleus
- 105 Downloads
The regulatory peptide leptin has a respiratory stimulating effect along with its well known hypothalamic effects. The present study, performed on anesthetized rats, addressed respiratory responses to microinjections of 10−10−10−4 M leptin into the solitary tract nucleus, which contains a high concentration of leptin receptors. Injections of 10−8−10−4 M leptin led to stimulation of respiration, inducing a dose-dependent increase in the level of pulmonary ventilation and an increase in respiratory volume, accompanied by an increase in bioelectrical activity in the inspiratory muscles; 10−6 M leptin also induced a transient increase in respiratory rate due to shortening of inhalation and exhalation. A characteristic feature of the response was the appearance of “sighs” – deep, prolonged inhalations accompanied by increased volley activity on the electromyograms of the inspiratory muscles and lengthening of the subsequent intervolley interval. These leptin effects, along with data on the high concentrations of specific leptin receptors (ObRb) in the solitary tract nucleus, suggested that endogenous leptin has a role in controlling respiration at the level of the dorsal segment of the respiratory center.
KEY WORDSregulation of respiration respiratory center solitary tract nucleus leptin
Unable to display preview. Download preview PDF.
- 1.E. N. Glazkova and A. N. Inyushkin, “Respiratory reactions to microinjection of bombesin into the solitary tract nucleus and their mechanisms,” Ros. Fiziol. Zh. im. I. M. Sechenova, 91, No. 5, 521–529 (2005).Google Scholar
- 2.A. N. Inyushkin, “Respiratory and hemodynamic reactions in rats to microinjection of opioids into the solitary tract nucleus,” Ros. Fiziol. Zh. im. I. M. Sechenova, 83, No. 3, 112–121 (1997).Google Scholar
- 3.A. N. Inyushkin and N. A. Merkulova, “Effects of microinjection of thyroliberin into the solitary tract nucleus area on measures of respiration and blood circulation,” Ros. Fiziol. Zh. im. I. M. Sechenova, 79, No. 11, 52–58 (1994).Google Scholar
- 21.R. A. Mitchell, H. H. Loeschcke, and N. H. Massion, “Respiratory responses mediated through superficial chemosensitive areas on the medulla,” J. Appl. Physiol., 18, No. 3, 523–533 (1963).Google Scholar
- 23.C. P. O'Donnell, S. D. Schaub, A. S. Haines, D. I. Berkowitz, C. G. Tankersley, A. R. Schwartz, and P. L. Smith, “Leptin prevents respiratory depression in obesity,” Amer. J. Respir. Crit. Care Med., 159, 1477–1484 (1999).Google Scholar
- 27.V. Y. Polotsky, J. A. Wilson, A. S. Haines, M. T. Scharf, S. E. Soutiere, C. G. Tankersley, P. L. Smith, A. R. Schwartz, and C. P. O'Donnell, “The impact of insulin-dependent diabetes on ventilatory control in the mouse,” Amer. J. Respirat. Crit. Care Med., 163, 624–632 (2001).Google Scholar