Biomedical subjects

D P Cardinali

Publications and source records attributed to D P Cardinali.

293 records · Page 17Linked to original sources

PubMedDate not supplied

GABA activity in dispersed bovine pineal cells: effect on serotonin release and calcium and chloride uptake.

The presence of gamma-aminobutyric acid (GABA) and peripheral and central benzodiazepine receptors in the mammalian pineal gland prompted the examination of GABAergic transmission in dispersed bovine pineal cells. The effect of GABA on 3H-serotonin (5HT) release was examined in bovine pineal cells. GABA, by acting through GABA B receptor subtype, decreased 5HT release and by acting through GABA B, and presumably through GABA A receptor subtypes, inhibited depolarization-induced 45Ca2+ uptake in bovine pinealocytes. GABA, by acting on GABA B as well as on GABA A receptors, prevented the 5HT2- or 5HT1C-mediated stimulatory effect of serotonergic agonists on calcium uptake in pineal cells. GABA augmented 36Cl- uptake by bovine pineal cells. These results are interpreted to indicate that, by regulating the release of 5HT, GABA may modulate the synthesis and action of melatonin.

Analysis of Variance↗

PubMedDate not supplied

Thyroid growth-stimulating and growth-inhibiting factors.

This article reviews the biological signals and factors involved in normal and pathological thyrocyte proliferation. The role of thyrotropin, cyclic adenosine 3'5'-monophosphate and hormones of anterior pituitary and placental origin are discussed. The effects on thyroid growth of insulin and insulin-like growth factors, epidermal growth factor and fibroblast growth factor are analyzed, as well as those of metabolites of arachidonic acid, iodide, neuropeptides like somatostatin, calcium metabolism and melatonin. Thyroid growth is also under the control of the sympathetic and parasympathetic nerves of cervical sympathetic and vagal origin, respectively. Involvement of growth-affecting factors that contribute as risk factors for thyroid tumorigenesis, and the pathological immunoglobulins stimulating or inhibiting thyroid growth are reviewed. The picture that emerges underlines the complexity of the regulating phenomena controlling thyroid growth.

Animals↗

PubMedDate not supplied

Influence of the autonomic nervous system on calcium homeostasis in the rat.

The local surgical manipulation of sympathetic and parasympathetic nerves innervating the thyroid-parathyroid territory was employed to search for the existence of a peripheral neuroendocrine link controlling parathyroid hormone (PTH) and calcitonin (CT) release. From 8 to 24 h after superior cervical ganglionectomy (SCGx), at the time of wallerian degeneration of thyroid-parathyroid sympathetic nerve terminals, an alpha-adrenergic inhibition, together with a minor beta-adrenergic stimulation, of hypercalcemia-induced CT release, and an alpha-adrenoceptor inhibition of hypocalcemia-induced PTH release were found. In chronically SCGx rats PTH response to EDTA was slower, and after CaCl2 injection, serum calcium attained higher levels in face of normal CT levels. SCGx blocked the PTH increase found in sham-operated rats stressed by a subcutaneous injection of turpentine oil, but did not affect the greater response to EDTA. The higher hypocalcemia seen after turpentine oil was no longer observed in SCGx rats. The effects of turpentine oil stress on calcium and CT responses to a bolus injection of CaCl2 persisted in rats subjected to SCGx 14 days earlier. Interruption of thyroid-parathyroid parasympathetic input conveyed by the thyroid nerves (TN) and the inferior laryngeal nerves (ILN) caused a fall in total serum calcium, an increase of PTH levels and a decrease of CT levels, when measured 10 days after surgery. Greater responses of serum CT and PTH were detected in TN-sectioned, and in TN- or ILN-sectioned rats, respectively. Physiological concentrations of CT decreased, and those of PTH increased, in vitro cholinergic activity in rat SCG, measured as specific choline uptake, and acetylcholine synthesis and release. The results indicate that cervical autonomic nerves constitute a pathway through which the brain modulates calcium homeostasis.

Animals↗

PubMedDate not supplied

2-[125I]iodomelatonin binding sites in murine mammary tissue.

2-[125I]iodomelatonin binds in vitro to murine mammary gland membranes, in a specific, saturable, reversible and temperature-dependent and pH-dependent way, displaying an affinity within the low nM range. The order of affinity to displace the radioligand from mammary membranes was: 6-hydroxy-melatonin > 5-hydroxyindoleamines > noradrenaline > 6-chloromelatonin > 5-methoxyindoles (melatonin included). There was a diurnal rhythm in Kd and Bmax of 2-[125I]iodomelatonin binding, displaying the highest affinity and the lowest binding site concentration during the scotophase. The functional significance of melatonin binding sites was indicated by changes in binding parameters related to different rates of mammary growth during puberty, estrous cycle, pregnancy, lactation and the postlactation period.

Animals↗

PubMedDate not supplied

[A survey of sleeping difficulties in an urban Latin American population].

AIMS: To report the results of the first regional survey on the prevalence of sleep disturbances in an urban Latin American population. SUBJECTS AND METHODS: Door-to-door and telephone interviews in main urban areas were performed in two phases. In phase one, 1776 adults, aged 18 to 70 were interviewed in Buenos Aires and São Paulo. In phase two, adults aged 18 to 77 were interviewed in Buenos Aires, São Paulo and Mexico City (n = 300 in each city). RESULTS: Two-thirds of those surveyed in phase 1, regardless of age and gender, reported some type of sleep problem within the last 12 months. Up to 25 % of individuals surveyed in phase 2 reported being severely affected or moderately affected by their sleep problems. The severity of the condition increased with age, women being more severely affected than men. On average, individuals reported suffering from sleep difficulties for a period of 5 years and were affected 15.5 nights per month. Although 8.2 hours of sleep was most desired, Latin Americans were sleeping on average 5.8 hours per night. Those severely affected lost about 3 hours per night. Individuals reported stress and worry as the primary trigger for their sleep problems, followed by health concerns. All respondents reported the negative impact of poor sleep on their health and quality of life. CONCLUSIONS: The survey indicates that the prevalence of sleep difficulties in an urban Latin America population is high.

Adolescent↗