Track topics on Twitter Track topics that are important to you
We tested the hypothesis that antagonism of progesterone receptor (PR) in newborn rats alters carotid body and respiratory responses to hypoxia and nicotinic receptor agonists. Rats were treated with the PR antagonist mifepristone (daily oral gavage 40 μg/g/d) or vehicle between postnatal days 3 and 15. In 11-14-day-old rats, we used in vitro carotid body/carotid sinus nerve preparation and whole body plethysmography to assess the carotid body and ventilatory responses to hypoxia (65 mmHg in vitro, 10% O2 in vivo) and to nicotinic receptor agonists (as an excitatory modulator of carotid body activity-nicotine 100 μM for in vitro studies, and epibatidine 5 μg/kg, i.p., which mainly acts on peripheral nicotinic receptors, for in vivo studies). The carotid body responses to hypoxia and nicotine were drastically reduced by mifepristone. Compared with vehicle, mifepristone-treated rats had a reduced body weight. The ventilatory response to epibatidine was attenuated; however, the hypoxic ventilatory response was similar between vehicle and mifepristone-treated pups. Immunohistochemical staining revealed that mifepristone treatment did not change carotid body morphology. We conclude that PR activity is a critical factor ensuring proper carotid body function in newborn rats.
Department of Pediatrics, Laval University, Centre de Recherche (D0-711), Hôpital St.-François d'Assise, 10 rue de l'Espinay, QC, G1L 3L5, Canada.
This article was published in the following journal.
Myometrium holds the structural integrity for the uterus and generates force for parturition with its primary component, the smooth muscle cells. The progesterone receptor mediates progesterone-depend...
Recent study showed that hypoxia activates a Ca(2+)-sensitive, Na(+)-permeable non-selective cation channel (NSC) in carotid body glomus cells. We studied the effects of mitochondrial inhibitors that ...
We tested the hypotheses that: (1) carotid body size can be measured by computed tomographic angiography (CTA) with high inter-observer agreement, and (2) patients with sleep apnea exhibit larger caro...
It has been demonstrated that κ-opioid receptor agonists can reduce hypoxia-ischemia brain injury in animal models. However, it is unclear how the κ-opioid receptor responds to hypoxia-ischemia. In ...
M3 muscarinic receptor antagonism has been associated with glucose intolerance and disturbance of insulin secretion.
Past research has demonstrated that cocaine dependent women experience less severe responses to cocaine during the luteal phase of the menstrual cycle, when estrogen and progesterone conce...
The general aim of this study is to define the response to hypoxic challenge in patients with diabetes. The investigation will provide response for different questions that are central for...
Climbing at high altitude and tolerating hypoxic environment require specific physiological adaptations. Large intersubjects differences exist regarding the ability to adapt to high altitu...
The purpose of this study is to help us determine how hormones impact the production of cervical mucus which is a fluid secreted by the opening of the uterus, also called the cervix. Durin...
Each year over a million patients worldwide undergo cardiac surgery requiring cardiopulmonary bypass (CPB). CPB is associated with significant morbidity including the transfusion of alloge...
A small cluster of chemoreceptive and supporting cells located near the bifurcation of the internal carotid artery. The carotid body, which is richly supplied with fenestrated capillaries, senses the pH, carbon dioxide, and oxygen concentrations in the blood and plays a crucial role in their homeostatic control.
Specific proteins found in or on cells of progesterone target tissues that specifically combine with progesterone. The cytosol progesterone-receptor complex then associates with the nucleic acids to initiate protein synthesis. There are two kinds of progesterone receptors, A and B. Both are induced by estrogen and have short half-lives.
Dioxygenase enzymes that specifically hydroxylate a PROLINE residue on the HYPOXIA-INDUCIBLE FACTOR 1, ALPHA SUBUNIT. They are OXYGEN-dependent enzymes that play an important role in mediating cellular adaptive responses to HYPOXIA.
Damages to the CAROTID ARTERIES caused either by blunt force or penetrating trauma, such as CRANIOCEREBRAL TRAUMA; THORACIC INJURIES; and NECK INJURIES. Damaged carotid arteries can lead to CAROTID ARTERY THROMBOSIS; CAROTID-CAVERNOUS SINUS FISTULA; pseudoaneurysm formation; and INTERNAL CAROTID ARTERY DISSECTION. (From Am J Forensic Med Pathol 1997, 18:251; J Trauma 1994, 37:473)
Pathological conditions involving the CAROTID ARTERIES, including the common, internal, and external carotid arteries. ATHEROSCLEROSIS and TRAUMA are relatively frequent causes of carotid artery pathology.
Prostate cancer (cancer de prostata) Prostate cancer (cancer de prostata) is a form of cancer that develops in the prostate, a gland in the male reproductive system. Most prostate cancers are slow growing; however, there are cases of aggressive prostat...
Asthma COPD Cystic Fibrosis Pneumonia Pulmonary Medicine Respiratory Respiratory tract infections (RTIs) are any infection of the sinuses, throat, airways or lungs. They're usually caused by viruses, but they can also ...