Acta physiologica Scandinavica. Supplementum
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Acta Physiol Scand Suppl · Apr 1999
ReviewOn the role of PGD2 metabolites as markers of mast cell activation in asthma.
Prostaglandin D2 (PGD2) is the major cyclooxygenase metabolite of arachidonic acid released after stimulation of mast cells. Quantification of metabolites of PGD2 can be used as an objective indices of PGD2 production and hence mast cell activation in vivo. The aim of this thesis was to investigate the feasibility of measuring the primary urinary metabolite of PGD2, 9 alpha,11 beta-PGF2 with enzyme immunoassay (EIA). ⋯ Seven of the subjects (responders) experienced bronchoconstriction, whereas, the pulmonary function of the remaining five subjects (non-responders) remained stable. The urinary excretion of 9 alpha,11 beta-PGF2 in the responder group increased significantly compared to the non-responders at 30 and 90 minutes after exercise. The urinary excretion of LTE4 and N tau-methylhistamine was not significantly different between the two groups at either time point after exercise, although there was a tendency for elevated levels of N tau-methylhistamine in the responder group. (ABSTRACT TRUNCATED)
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Acta Physiol Scand Suppl · Jan 1995
Autoradiographic visualization and pharmacological characterization of vanilloid (capsaicin) receptors in several species, including man.
Sensory neurons sensitive to vanilloids (the paradigm of which is capsaicin, the pungent principle in hot peppers) were visualized by [3H]resiniferatoxin (RTX) autoradiography in several species, including man. Vanilloid binding sites were detected in somatic (trigeminal and dorsal root) and visceral (nodose) sensory ganglia, peripheral (vagal and sciatic) nerves, dorsal horn of the spinal cord, as well as in nuclei in the central nervous system receiving sensory input, such as the nucleus of the solitary tract (containing vagal afferents) and the spinal trigeminal nucleus. Twenty four hrs after ligation of the vagal or the sciatic nerves, a strong accumulation of specific RTX binding sites was observed proximal to the ligature, implying anterograde intraaxonal receptor transport from the nodose and dorsal root ganglia, respectively, to the periphery. ⋯ In conclusion, specific binding of [3H]RTX provides a unique tool to visualize vanilloid receptors and to study their pharmacology. A heterogenous vanilloid receptor system is emerging with types/subtypes, and marked species-related differences. The interaction of protons and neuroleptics at vanilloid receptors may provide a rational basis to explain their actions on on primary sensory neurons.
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Acta Physiol Scand Suppl · Jan 1994
Comparative Study Clinical TrialCardiovascular and pulmonary responses to breath-hold diving in humans.
Cardiovascular and pulmonary responses to breath-hold diving (breath holding, submersion, and compression) were investigated. In addition, the effects of transitions between dry conditions and head-out immersion during eupnea were studied. Surface breath holds at a large lung volume with relaxed respiratory muscles resulted in a positive esophageal (transthoracic) pressure and a reduced cardiac output. ⋯ Changes in the intrathoracic pressure and in the distribution of venous blood volume induce changes in cardiac output. All of these changes affect the temporal and spatial distributions of pulmonary perfusion and peripheral blood flow. Also, the circulatory changes affect the temporal and spatial distributions of alveolar gas exchange and of tissue gas stores of the body.
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Acta Physiol Scand Suppl · Jan 1992
Diuresis and natriuresis following isotonic saline infusion in healthy young volunteers before, during, and after HDT.
In the present study the response to acute saline loading was investigated. During a 24-day study period six male subjects followed a standardized diet including a daily intake of 40 ml water and 125 mg NaCl per kg body weight. Before, during, and after a ten-day period of 6 degrees head down tilt (HDT) each volunteer received an intravenous 0.9% saline infusion of 22 ml/kg body weight over 20 minutes. ⋯ The long-term renal response was paralleled by an increased excretion of urinary cyclic GMP. HDT produced significant changes in body fluid distribution, but only minor changes in the regulatory responses to an acute saline load. We conclude from these data that the excretion of an acute isotonic saline load requires several days and that the renal response appears to be independent of the secretion of ANP from the heart.