Biomedical subjects

C Hedetoft

Publications and source records attributed to C Hedetoft.

5 recordsLinked to original sources

PubMed2000

Pituitary adenylate cyclase-activating peptide stimulates acute progesterone production in rat granulosa/Lutein cells via two receptor subtypes.

Pituitary adenylate cyclase-activating peptide (PACAP) is transiently expressed in ovarian granulosa/lutein cells from eCG/hCG-treated rats, and in vitro immunoneutralization of endogenously released PACAP inhibits acute progesterone secretion and subsequent luteinization in such cells. This suggests that PACAP mediates locally some of the effects of the LH surge, but the putative PACAP receptor(s) involved in such an auto or paracrine activity is presently unknown. Reverse-transcription polymerase chain reaction with specific primers to the three cloned PACAP-binding receptors called PAC(1), VPAC(1), and VPAC(2) demonstrated both PAC(1) and VPAC(2) mRNA in extracts from preovulatory follicular cells. Radioligand-binding assays revealed the presence of high-affinity binding sites with characteristics of these two receptors on the intact cells, and autoradiography demonstrated that the binding was restricted to a minor proportion of the follicular cells as well as the oocytes. Pituitary adenylate cyclase-activating peptide and vasoactive intestinal peptide (VIP) dose-dependently stimulated cAMP accumulation and acute progesterone accumulation. Forskolin and db-cAMP also stimulated acute progesterone accumulation, and the protein kinase A inhibitor H89 dose-dependently inhibited peptide induced acute progesterone accumulation, suggesting involvement of cAMP and the protein kinase A pathway in the process. In conclusion, two of the three PACAP binding receptors are present on preovulatory follicular cells and are involved in the effects of PACAP on acute progesterone production. The data provide further evidence to establish PACAP as an auto- or paracrine regulator of LH-induced acute progesterone production in rat preovulatory follicles.

Animals↗

PubMed2000

Effect of glucagon-like peptide 1(7-36)amide in insulin-treated patients with diabetes mellitus secondary to chronic pancreatitis.

Diabetes mellitus secondary to chronic pancreatitis is characterized by a progressive destruction of the pancreas, including loss of the islet cells, leading to a form of diabetes that can mimic both type 1 and type 2 diabetes. Glucagon-like peptide 1(7-36)amide (GLP-1), an intestinally derived insulinotropic hormone, represents a potential therapeutic agent for type 2 diabetes, because exogenous GLP-1 has been shown to increase the insulin and reduce the glucagon concentrations in these patients, and thus induce lower blood glucose, but without causing hypoglycemia. Ten patients with diabetes mellitus secondary to chronic pancreatitis and five normal subjects were studied. Nine patients were treated with insulin and one patient with sulfonylurea. In the fasting state, saline or GLP-1 in doses of 0.4 or 1.2 pmol/min/kg body weight were infused intravenously for 4 hours. Blood glucose was reduced in all patients with both doses of GLP-1; plasma C-peptide increased (p<0.02), and plasma glucagon decreased (p<0.02) compared with basal levels, also in three patients with normoglycemia and high levels of presumably exogenous insulin. Similar results were obtained in the normal subjects. In conclusion, GLP-1 treatment may be considered in patients with diabetes mellitus secondary to chronic pancreatitis, provided that a certain amount of alpha- and beta-cell secretory capacity is still present.

Aged↗

PubMed1999

[Amphetamine, ecstasy and cocaine. Clinical aspects of acute poisoning].

Consumption of the illicit drugs amphetamine, ecstasy and cocaine is increasing in Denmark and Europe leading to an increasing number of intoxications with these drugs. Abroad, several deaths after ingestion of a few doses of the drugs have been reported. Amphetamine, ecstasy and cocaine increase the amount of dopamine, norephedrine and serotonine in the nervous system, resulting in CNS stimulation and a general sympathomimetic stimulation. Symptoms to be treated originate mainly from the CNS and the cardiovascular system, and present as tachycardia, hypertension and seizures, later hypotension and coma. Hyperpyrexia, rhabdomyolysis and affections of the kidneys, lung and liver function are also often seen. Hyperpyrexia is an important marker of poor prognosis, and must be handled aggressively. A review of the literature concerning the optimal treatment based on pharmacological and diagnostic considerations is given in the article.

Amphetamine↗

PubMed1999

[Fatal poisoning with Letigen].

The anorexic agent Letigen, which contains 200 mg coffeine and 20 mg ephedrine, has been extensively used during the last decade. The case report describes a 19 year-old woman who ingested 50 Letigen tablets in a suicidal attempt. She developed severe toxic manifestations from the heart, CNS, muscles, liver and kidneys leading to several cardiac arrests, and died subsequently of cerebral oedema and incarceration on the fourth day of hospitalization. Because of the potentially life-threatening intoxication following an overdose, prescription of Letigen must be carefully administered.

Adult↗

PubMed1997

Leptin: a potent inhibitor of insulin secretion.

The hormone leptin is expressed and secreted by the adipose tissue and impacts on the central nervous system. Leptin is involved in the regulation of energy balance, satiety, and body composition. The lack of active leptin results in obesity, high food intake, hyperglycemia, and hyperinsulinemia. We present data supporting effects of leptin on the endocrine pancreas. We found the leptin receptor to be expressed in insulin- and glucagon-secretin cells derived from mouse, hamster, and rat pancreas. In the isolated perfused rat pancreas leptin is a potent inhibitor of basal and glucose-induced insulin secretion, especially during the first phase of the insulin response. At isolated mouse islets and insulin-secreting INS-1 cells leptin reduced promptly and persistently the intracellular Ca2+ levels. Cytoplasmic Ca2+ oscillation amplitude was decreased and the oscillation frequency increased. These findings suggest functional active receptors for leptin on insulin-secreting B-cells. Therefore, leptin is a metabolic hormone and not only a signal to the brain indicating filled fat stores. Our data suggest that leptin is also a signal back to the endocrine pancreas that no more insulin is required to replenish fat stores. Thus, an "adipo-insular axis" operating with two arms exists: insulin and glucagon are signals to the adipocyte. This releases leptin, which could be the mediator of the respective feedback to the pancreas. A defective leptin suppression of insulin secretion could contribute to hyperinsulinemia and disturbances of glucose metabolism.

Animals↗