Cardiovascular effects of the intracerebroventricular injection of adrenomedullin: roles of the peripheral vasopressin and central cholinergic systems

Our objective was to investigate in conscious Sprague-Dawley (6-8 weeks, 250-300 g) female rats (N = 7 in each group) the effects of intracerebroventricularly (icv) injected adrenomedullin (ADM) on blood pressure and heart rate (HR), and to determine if ADM and calcitonin gene-related peptide (CGRP) receptors, peripheral V1 receptors or the central cholinergic system play roles in these cardiovascular effects. Blood pressure and HR were observed before and for 30 min following drug injections. The following results were obtained: 1) icv ADM (750 ng/10 µL) caused an increase in both blood pressure and HR (DMAP = 11.8 ± 2.3 mmHg and ΔHR = 39.7 ± 4.8 bpm). 2) Pretreatment with a CGRP receptor antagonist (CGRP8-37) and ADM receptor antagonist (ADM22-52) blocked the effect of central ADM on blood pressure and HR. 3) The nicotinic receptor antagonist mecamylamine (25 µg/10 µL, icv) and the muscarinic receptor antagonist atropine (5 µg/10 µL, icv) prevented the stimulating effect of ADM on blood pressure. The effect of ADM on HR was blocked only by atropine (5 µg/10 µL, icv). 4) The V1 receptor antagonist [β-mercapto-β-β-cyclopentamethylenepropionyl¹, O-me-Tyr²,Arg8]-vasopressin (V2255; 10 µg/kg), that was applied intravenously, prevented the effect of ADM on blood pressure and HR. This is the first study reporting the role of specific ADM and CGRP receptors, especially the role of nicotinic and muscarinic central cholinergic receptors and the role of peripheral V1 receptors in the increasing effects of icv ADM on blood pressure and HR.

Fluid balance: changes in cycling rats treated with difluoro-methyl-ornithine [DFMO] during the pro-oestrus.

Plasma vesopressin levels have been shown to fluctuate through out the rat oestrus cycle and following ovariectomy. To determine how these fluctuations in vesopressin are related to fluid regulations during the rat oestrus cycle. Studies have been carried out in cycling females rats using a specific inhibitor of Ornithine Decarboxylase [ODC], Di-fluoro-methyl Ornithine [DFMO 20 mg/100g body weight], the animals were housed in individual metabolism cages under 12 hours light/12 hour dark regimen with free access to food and water. Urine samples were collected to determine the osmolality and sodium concentration at 8.00 and 17.00-18.00 hours. The results of this study indicate a significant decrease in urine osmolality and sodium retention in the cycling pro-oestrus rats treated with DFMO as compared to the controls. The result of this study indicates that cause of fluid retention in the cycling rats during pro-oestrus may be the oestradiol dependent increased levels of vesopressin and the increase in the ODC activity in the Magno-cellular neurons is the part of mechanism underlying the oestradiol induced Vesopressin release

Acetato de desmopresina en niños enuréticos resistentes a terapias convencionales / Desmopressin acetate in children with conventional therapy resistant enuresis

Se describen los resultados obtenidos con acetato de desmopresina en aerosol por inhalación nasal en 29 niños (15 varones) entre 8 y 10 años de edad, que sufrían enuresis nocturna resistente a tratamiento con imipramina sola y/o asociada a ácido oxibutinino. En todos ellos la anatomía y función vesical eran normales y ninguno sufría enfermedades neurológicas o renales. La desmopresina se suministró en dosis diarias de 10 µg que fueron aumentadas semanalmente, si era necesario, en igual proporción, hasta obtener uno o ningún episodio semanal de enuresis o un máximo de 40 µg diarios del fármaco. La dosis así titulada se mantuvo por 3 meses, al cabo de los cuales se redujo progresivamente en 10 µg semanales hasta suspenderla. Los pacientes fueron seguidos hasta un mes después de la supresión del tratamiento. Se obtuvo buen éxito (uno o menos episodios de enuresis por semana) en 65 por ciento de los casos. Un mes después de suspender la desmopresina se registraban 62,2 por ciento de niñoscon uno o menos episodios semanales de enuresis, sugiriendo una baja proporción de recaídas en plazos cortos. No se anotaron efectos colaterales importantes duarnte el estudio en este grupo de niños, salvo cefalea persistente en un paciente con antecedentes de jaqueca

study of antidiuretic hormone and aldosterone in children with grand epilepsy as influenced by drug therapy

This study was conducted on thirty children with grand mal epilepsy attending the paediatric neurology clinic of the Alexandria University Hospital for Sick Children, all of them were new untreated cases. The diagnosis was built up on both clinical and electroencephalographic grounds. Children were divided into two major groups; the first group received CBZ as the sole drug of therapy, the second group received sodium vaiproate as the sole antiepileptic drug. Serum and urinary sodium, potassium, osmolality, serum aldosterone and plasma ADH were determined for all the cases before initiation of therapy and three months later. Twenty normal age matched children without personal or family history of epilepsy or febrile convulsions were included in this study as controls and subjected to the same laboratory investigations